Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => General Discussion => Topic started by: TJ Hopland on December 31, 2014, 09:46:50 PM

Title: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on December 31, 2014, 09:46:50 PM
Just wondering how many people here currently own a diesel Cadillac?   

I still have my 80 Eldo but after a deer hit have not been driving it.   Sort of replaced it with an 81 Riv diesel but its just not a Cadillac.

There has to be some others out there still running.       
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Barry M Wheeler #2189 on January 03, 2015, 01:25:31 PM
Lars has a nice one.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 03, 2015, 02:29:51 PM
I know there are a few.   I occasionally get an email or PM from someone asking questions.  Just for some reason they don't seem to want people on the board to know they have one and like it.   Lately I have noticed a lot more people with 4100 era cars 'coming out' so I thought maybe some more diesel folks would appear.  Maybe they are just that rare today?    I suppose you take the number of 4100 people here vs the number sold and apply that same formula to the diesels it makes sense that there are none here.   Then you could factor in the 'survival rate' and none should still exist. 
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: David King (kz78hy) on January 03, 2015, 03:20:17 PM
I would love to have Seville diesel.  Back in '84, I had a '81 Sedan DeVille diesel and loved it.  The car was stolen and I replaced it w/a gas Seville, but I would not be afraid of the later designed 350 diesel.

David
Title: Anyone else currently own a 78-85 Cadillac diesel?
Post by: bcroe on January 03, 2015, 07:33:43 PM
I drove a few of those diesels, 3 are still here (converted after the diesel died). 
If you convert a RWD to a switch pitch trans, you will be amazed at the
improvement in performance.  That, because it gets the engine into its power
band far sooner.  The only reason a 120 hp engine can't move a car smartly
around town, is poor gearing.  Bruce Roe
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Eric DeVirgilis CLC# 8621 on January 04, 2015, 12:45:20 PM
Diesels are definitely scarce today; many were traded, converted and/or scrapped while in their prime. The few owners who followed all maintenance directives to a T had far better service from their diesels than those who didn't.

The fact that gasoline powered Cadillacs up until 1980 required very little by way of conscientious & deliberate care probably did not help matters any: Newbie diesel owners were unprepared - more or less - for the special needs of their machines.

Probably the rarest of the rare in diesel Cadillac is the 1986 FWD DeVille/Fleetwood. I only saw one in my entire life - a 1986 Fleetwood Sedan, brown with beige leather.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Walter Youshock on January 04, 2015, 01:20:43 PM
Former owner of a funeral home I worked at bought a new early '80's diesel.  The car was so loud, he said he had to dump it after about 6 months.  Families were complaining about how noisy it was.

I went to college with an older lady who's husband bought her a ne '81 diesel sdv.  She said the car left her stranded so many times, she dumped the car AND the husband!
Title: Anyone else currently own a 78-85 Cadillac diesel?
Post by: bcroe on January 04, 2015, 01:52:27 PM
Quote from: ericdevDiesels are definitely scarce today; many were traded, converted
and/or scrapped while in their prime. The few owners who followed all maintenance directives
to a T had far better service from their diesels than those who didn't.

The fact that gasoline powered Cadillacs up until 1980 required very little by way of conscientious & deliberate care probably did not help matters any: Newbie diesel owners were unprepared - more or less -
for the special needs of their machines.   

My first diesel was an early 80 model; next was a replacement engine in an 81.  As I recall
we put a special pickup (recall) in the 80 tank; about the only maintenance was oil changes
and oil & filter changes done religiously.  At about 40K miles the (now notorious) poor quality
injection pump developed a problem.  The dealer managed to fix that, but the engine now
had what sounded like a rod knock.  The (either incompetent or completely dishonest) dealer
informed me I needed to put in a new engine and trade in the car on a new one.  After telling
him where he could go (trade my NEW car??), I put in a gas engine.  Seems I created a car
with lots of extra sound proofing, super duty electrical system, hydro boost brakes, 28 gallon
gas tank with no gas restrictor, high flow exhaust with no cat converter, and no emissions
testing ever.  Currently my best car ever at over 300K.   I eventually took the the rods off
the diesel engine crank; the bearings were like new.  Reading the manual revealed the noise
was caused by a defective fuel injector (put in by the dealer).  The engine is still here too,
just in case. 

So I could pick up great diesel cars for a song when the engine or (crappy) TH200 trans
failed.  I had and converted a few to gas back then.  The second engine in the 81 eventually
failed too.  By now the price of diesel was far above gasoline, instead of far below; I saw no
reason to try and keep the diesel going.  That Cutlass with 403 engine and a mere 220,000
miles is still here too, for reasons mentioned above. 

Perhaps the diesels were just about upgraded enough when they were dropped; too bad.  The
V6 I took apart had a lot more reinforcement in the block than the first V8s.  Still needed a
better injection pump.  Maybe some owners were lax, but even those who were meticulous
experienced failures.  The way to go is the turbo diesel.  Bruce Roe
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Big Apple Caddy on January 04, 2015, 01:53:24 PM
Quote from: ericdev on January 04, 2015, 12:45:20 PMProbably the rarest of the rare in diesel Cadillac is the 1986 FWD DeVille/Fleetwood. I only saw one in my entire life - a 1986 Fleetwood Sedan, brown with beige leather.

1986?  Did you mean 1985?  I thought production of the 4.3L V6 diesel used in the FWD Electra, 98 and DeVille/Fleetwood models ended in late 1984, maybe early 1985.  Too early to be available in a 1986 model.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Dr. John T. Welch on January 04, 2015, 02:43:04 PM
There are only two kinds of GM 5.7L diesel engines:  those that failed catastrophically between 75K and 100K miles and those that will. Any exceptions are just that: random good fortune. I've owned ,used and converted several of these diesel powered vehicles in various GM platforms.

In correspondence with the Oldsmobile Division Chief Engineer  during  the heyday of the 5.7 diesel engine experience, I was assured of GM's commitment to customer satisfaction and the solid warranty provisions covering the powertrain. Here are the empirical facts about the 5.7L  and derivative 4.3L  engine programs:

The engines were developed to allow an accelerated compliance with emerging EPA corporate average fuel economy (CAFE) statutes. This was a major cross divisional program including passenger cars and very light duty GMC and Cheverolet pickup trucks. This was no small feat from an engineering and manufacturing standpoint for GM.

The program was not viable financially within the proscribed time frame without using existing  manufacturing resources for the major cast engine components: block, cylinder heads, camshaft, crankshaft. An existing engine architecture was chosen after evaluation of several possibilities: the Oldsmobile Division "small block" V-8 whose development and manufacturing costs were already fully amortized. The machining of these major  components occurred on the same lines as the conventional gasoline engines, minimizing manufacturing costs.

The main problem with the service life of the engines derived from the vibrations and related harmonics  inherent in  diesel combustion.
The block/head assembly did not fare well with vibration propagation through it, resulting in broken headbolts and cracked cylinder heads that led to catastrophic hydrolocking and engine destruction. Early indicators of the problem were coolant in the oil and white smoke out the exhaust that masqueraded as simple headgasket failure.  A particular concentration of severe second and third order harmonic phenomena occurred at the lower left area of the block at the starter mounting boss. GM went through three designs of the starter motor cast aluminum end housing attempting to defeat the fracture of this piece from vibrations transmitted to it during normal engine operation. Also afflicted in a similar way were rocker arm pedestals and some accessory mounting brackets in the front of the engine.  No amount of customer compliance with recommended maintenance schedules would defeat these inherent destructive forces.   
 
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 04, 2015, 04:36:08 PM
What I have found since I have become a diesel enthusiast is that about 95% of what I have always heard about diesels (especially when it comes to the early 80's) is just not true.   Some of it was never true and then the rest was mostly related what was available for fuel, oil, and service at the time.  If you think back to 1980 there just was not a lot of diesel stuff around especially at the average consumer level.  Lighter construction equipment was all gas, heck even some of the bigger stuff was still gas.  Only the larger farm equipment was diesel.  City delivery trucks were gas, some 'semi's' were even gas.  The GM ads from the era told you to stop by and get a pamphlet showing you where you could buy diesel fuel so just finding it had to be a big issue for some buyers if gm bothered to print those and advertise / distribute them.   

The fuel at the time was prone to algae growth and gelling in cold climates.   Factor in how leaky a lot of underground tanks were at the time you also got a lot of water issues which is a much bigger issue for diesels than gas engines.   Take a leaky tank in a low volume gas station and you could be lucky to get any actual diesel fuel out of the pump.  EPA has taken care of the leaky tanks.  Fuel formulas have improved so you typically don't have gelling or algae issues.   The engine oils have dramatically improved.   I heard often times in the 80's a Cadillac dealer may not have had diesel rated oil in stock.  You often had to run out to a 'truck stop' or an ag (tractor) dealer to get a diesel motor oil (maybe that is also where you had to go for your fuel?).   Today I would say 1/2-3/4 of 'gas' stations have diesel.   Many of them have at least one option for a diesel rated oil and fuel treatment on the shelf.   You can go to a walmart and have a dozen options for a diesel rated oil.    My 2013 Jetta looks, sounds, smells, starts, and drives like any other 2013 Jetta, only difference is I typically go over 600 miles without having to stop to fill up.   My Suburban can go 800 miles but that is a 42 gallon tank, vs the 12 ish of the Jetta.   

Just for fun when you are out driving start looking close at all the VW's you see, look for the TDI badge on the back.   I bet you will be amazed how many are actually out there.  I never really noticed till I started thinking about buying one.   Some parts of the USA it almost seems like half the ones you see are diesels.   The current $1 ish spread between gas and diesel is not an incentive at the moment but the previous 9 months it was a lot closer so you had a pretty good shot and some savings for many applications.

The 80's ones were loud on the outside so I can see where an application like the funeral home was maybe a problem.   Amazingly Cadillac and Olds really did an excellent job of insulating all that noise from the interior.   Going down the highway in my 80 you would not know its a diesel.   I am not sure if the lower models got the same treatment, the few Chev's I have been in were kinda loud but that could also have been an age thing. 

The Rosamaster (now Stanadyne) injection pump basic design I think dates back to the 1930's or 40's.  Got to be commonly used in the 1950's I think.   Same basic pump was used on several smaller tractors including John Deere and International.  Was used on all the GM light diesels through 2000ish.  Used on all the US light us military vehicles (I think it still may be used). Used on all the Ford diesel pickups till the mid 90's.         

The 85's apparently had a lot of changes so it really appeared they thought the program was going to continue even though it looked like sales had fallen pretty badly, likely a combination of the reputation and raising fuel prices.   Also don't forget that the early 80's a full size car with the Chev or Olds 5.0 could see 20 mpg.  When the program started you would be lucky to see mid teens from your full size car and small cars were really terrible so the prospect of getting 20's for MPG from a cheaper fuel and keep the comfort of you land yacht really appealed to a lot of people. 

I have never heard of any actually titled as 86's.   Have heard of fairly late build date 85's but that was likely due to all the problems they had getting the FWD C's into production, I would imagine they focused on the gas ones first since those were likely bigger sellers.   People also said the had seen a diesel option listed in many of the 86 parts manuals at the time. 
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 04, 2015, 04:59:44 PM
I was curious and looked up the 86 passenger car VIN chart and the only diesel listed there was a 4cyl produced in Japan.  Apparently they knew they were giving up by the time they produced the VIN charts.   I also didn't know GM had a plant in Japan in the mid 80's. 
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Eric DeVirgilis CLC# 8621 on January 04, 2015, 05:01:13 PM
Quote from: Big Apple Caddy on January 04, 2015, 01:53:24 PM
1986?  Did you mean 1985?  I thought production of the 4.3L V6 diesel used in the FWD Electra, 98 and DeVille/Fleetwood models ended in late 1984, maybe early 1985.  Too early to be available in a 1986 model.

I did. Thanks for the correction.


I've known a number of people over the years who positively swear by the 350 diesel - but these were people intimately familiar with these engines as well as which years were the best and which to avoid.

Supposedly the Goodwrench "Target" replacement engine had been thoroughly reengineered to address the maladies for which the 350 became infamous. The injection pump was also a well known weak point.

Despite the many myths surrounding the diesel's kinship to its gasoline counterpart, there was very little in commonality between the two other than displacement and V-8 configuration. Recently I had read a detailed article on the subject but I cannot recall where I saw it.
Title: Anyone else currently own a 78-85 Cadillac diesel?
Post by: bcroe on January 04, 2015, 08:16:39 PM
Quote from: ericdev
Despite the many myths surrounding the diesel's kinship to its gasoline counterpart, there was very little in commonality between the two other than displacement and V-8 configuration.   

I have spent a lot of time 5.7L diesels and Olds gas engines, and swapping their parts.  The
350 Olds is a direct bolt in; essentially everything fits.  Sure the power producing internal
parts are all reworked for the diesel.  But all the geometry is the same, including all the
common accessory mounts.  Valve covers, oil pan, oil filter mounting, oil pump, and more
have been swapped here.  An Olds 425 crank drops in. 

AND the worlds biggest small block, Olds 403, also drops in, with even more in common with
the gas 350.  I know they only claimed some 160 hp from the 403.  But with the right spark
advance curve (not that emissions version) and a really good exhaust, my measurements
calculate out to 260 hp.  My "diesels" surprised a lot of people.  Bruce Roe
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: 936CD69 on January 04, 2015, 08:30:24 PM
.  My "diesels" surprised a lot of people.  Bruce Roe
LOL sounds like the 403 I pulled from a 77 88 freshened up, with a mild cam, standard intake and carb and headers for a 260, dropped into a 78 Cutlass. Wasn't much around that could touch it in the 1/4. With 3.73 posi it was out of breath at 85 turning about 6000....

Bruce can you give an explanation of your "switch pitch" trans conversions..or perhaps have it on your website?

Craig
Title: Anyone else currently own a 78-85 Cadillac diesel?
Post by: bcroe on January 04, 2015, 09:38:48 PM
Quote from: 936CD69.  My "diesels" surprised a lot of people.  Bruce Roe
LOL sounds like the 403 I pulled from a 77 88 freshened up, with a mild cam,
standard intake and carb and headers for a 260, dropped into a 78 Cutlass. Wasn't
much around that could touch it in the 1/4. With 3.73 posi it was out of breath
at 85 turning about 6000....
Bruce can you give an explanation of your "switch pitch" trans conversions..or perhaps
have it on your website?  Craig   

You would be far ahead of my 2.41 cruising axle in the 1/4 mile, but the car measured
a 91.2 MPH quarter and still climbing (would do 100 in second). 

All big block 65-67 Buick, Olds, and Cads used a switch pitch trans, other years can be
converted.  A normal torque converter gives about a 2:1 torque increase stopped,
gradually decreasing to a straight 1:1 fluid coupling over some 3000 rpm.  So it stretches
the useful range of each gear, compared to a stick.  A 3 speed TH400 has a great advantage
over a 3 speed stick. 

Normally with the car stopped, the engine is limited to some 1500 rpm "stall" speed,
below its best power band.  Racing "high stall" converters will allow the engine to rev well
above 2000 rpm, getting at more power to begin with.  But racing converters are dogs on
the street, since the car won't move till 2000 rpm. 

The switch pitch converter allows changing any time between low stall and a modestly
high stall operation.  This comes with somewhat more than initial 2:1 torque multiplication. 
This is useful in getting any vehicle going, I used it for diesels and late 70s with 2.41:1
"gas economy" rear axles.  WIth a properly running engine, it reduced the 0-60 time
of my Olds by a full second, and it will do the same for a 70s Seville.  Meanwhile the gas
mileage is the same or just a bit better, with a 2 state converter instead of a single
compromise.  I use electronic pitch control, the OEM control wasn't very effective. 

Bruce Roe
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 04, 2015, 10:26:06 PM
The Olds museum has a V5 diesel on display.   It was supposed to be the diesel engine option for the small and mid size transverse FWD cars.  It never went into production because they pulled the plug on the whole program.  Just one more thing they were spending money on and then abandoned when they maybe finally got it right. 

Apparently the transverse FWD 4.3v6  cars has some major overweight weight issues.   I read that they had a lot of lightweight body parts up front to try and lighten things up.  Compared to a 4100 or typical V6 I suppose they were a little on the heavy side.  I never looked close, I would imagine the had two batteries like the 5.7's did which is just more weight and space.

There is a guy on one of the diesel forums that is on his 3rd or 4th 85 diesel coupe deville (or maybe they were Fleetwoods?).  I think total Cadillac diesel production for 85 was only around 1000 cars so a coupe has got to be rare.  He thinks maybe as few as 100 were made. 

I have dealt with Olds 403's and they really should not have been a good engine but they seemed to be reliable and you could get some good power out of em.  Most of the other engines they squeezed that size bore in had lots of issues.  Lots of those ended up in Firebirds as well as your full sized land yachts.     
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: wrench on January 04, 2015, 10:50:08 PM
I don't know about any Caddy's still running diesel, but I had one of those in a 82 Olds Cutlass Cruiser wagon...got to the point i could replace the head gasket blindfolded. I still have that special wrench for the injection pump...jeez that motor was a boat anchor...but I did run it on free sumped jet fuel with a little bit of marvel mystery oil and that thing ran like a locomotive and got great gas mileage...just the head gasket would blow every 15k miles or so...

I remember going to the local Olds dealer and asking for a new set of head bolts...the parts guy says 'Set?'...'There's no set. You have to look up each bolt as a separate line item AND pay freight in for each one'...Now that's customer service...bah!

And the torque on the head bolts was what? 160 foot pounds? Or some ungodly amount of torque you could barely apply...
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 04, 2015, 11:08:05 PM
I have heard a lot of stories about diesel wagons.  They must have sold quite a few.  There does not seem to be a lot of survivors.  I suppose it was the mileage appeal there too, 9 passengers and decent mpg for the big family vacation. 
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Eric DeVirgilis CLC# 8621 on January 05, 2015, 09:45:10 AM
Quote from: bcroe on January 04, 2015, 08:16:39 PM
I have spent a lot of time 5.7L diesels and Olds gas engines, and swapping their parts.  The
350 Olds is a direct bolt in; essentially everything fits.  Sure the power producing internal
parts are all reworked for the diesel.  But all the geometry is the same, including all the
common accessory mounts.  Valve covers, oil pan, oil filter mounting, oil pump, and more
have been swapped here.  An Olds 425 crank drops in. 

Correct, externals are the same.

Internals are very different - and the diesel weighs 500 lbs more than the gasoline version.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 05, 2015, 10:21:54 AM
It made a lot of sense to make things the same.  Using the same 'tin' and bolt on accessories likely saved them tons.  If they were more or less the same on the outside it would require less changes to install them in the cars.   By that time I think every car but the Corvette already had an Oldsmobile engine option.   Even the 6.2 diesel that came out in 82 was designed to replace a gas engine.   Basic dimensions were similar.   Same bellhousing.  Exhaust manifold dumps in the same spots, stuff like that.   

Over all the concept worked well for the Olds but one major area they should not have done that was the head bolt design.  That also came directly from the gas engine.  Most diesels have at least 4 bolts per cylinder.  The olds had 10 per head, a typical 4 cylinder diesel head would have at least 18.   

I imagine on paper and even 'in the lab' 10 was enough but in the real world of 1980 diesel that design did not leave any margin for error (or abuse) including the quality and spec of the original bolts they apparently used.   If they would have come up with a better head clamping design originally or even with their first major redesign around 80 the outcome would have likely been a lot different.   The transverse V6's that came out around 83 did have a much better design.   I would imagine they didn't bother to put it on the 5.7 because after 85 there were not going to be many cars that would want a 5.7, remember most of the RWD cars were gone by 87.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Big Apple Caddy on January 05, 2015, 12:44:35 PM
In the early 1980s, Cadillac was still playing up resale value advantages of the diesels.  Attached is part of a 1982 brochure.  It wouldn't be too long, however, before Cadillac and other GM passenger car diesels would be seeing major value deductions!
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: James Landi on January 05, 2015, 01:07:45 PM
WOW-- the "LAST REASON"--- gets my conspiratorial nerves on end! Did the marketing department already know that this model was the least valuable among the fleet?  I wish to mention Dr. Welsh's commentary in previous posts here as well.  The GM engineers were struggling with block failures...as he mentions, cracks in the castings that developed overtime. I have read many posts about the poor quality of available diesel, the lack of water separator filters in passenger vehicles, and the blown gaskets due to hydrolock... but aluminum durability appears to be an issue as Dr. Welsh cites, and does it not continue to be an issues for the next three and a half decades ?
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Eric DeVirgilis CLC# 8621 on January 05, 2015, 01:21:36 PM
Depending upon when that ad copy was written, they would have been correct - at least according to NADA guide and other so-called blue book publications.

I seem to remember the "Add for Diesel" adjustment as late as 1981 or 1982; within a very short time the "Add" became "Deduct for Diesel -$500 and shortly after that it became "Deduct 50% of Trade In Value for Diesel."

Say what you will but the fact is that there is a definite "cult" following for the once-maligned power plant today and you'll see no shortage of interest/activity on GM diesel powered cars when they do appear on eBay.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Big Apple Caddy on January 05, 2015, 02:16:34 PM
Quote from: James Landi on January 05, 2015, 01:07:45 PM
WOW-- the "LAST REASON"--- gets my conspiratorial nerves on end!

It was an interesting choice of words given how things turned out.  Perhaps there was an "inside joke" going on there.

There were already known and notable problems with the diesels by September 1981 but I guess it took a little while longer for the resale market to reflect these issues.

I believe 1981 was the sales peak for the GM passenger car diesels but with falling gasoline prices, more widely known reliability issues, etc. the market for these engines quickly declined over the next few years.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Big Apple Caddy on January 05, 2015, 02:17:42 PM
Quote from: ericdev on January 05, 2015, 01:21:36 PM
Say what you will but the fact is that there is a definite "cult" following for the once-maligned power plant today and you'll see no shortage of interest/activity on GM diesel powered cars when they do appear on eBay.

Very true.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Dr. John T. Welch on January 05, 2015, 11:14:45 PM
The marketing of the VIN code L 5.7L diesel powered vehicles was problematic.  Because this was a centrally mandated cross divisional powertrain option (meaning a forced factory option in addition to all the divisions' established standard and  optional  gasoline engines) and each division had its own advertising agency, the marketing and advertising came in many flavors.  Suddenly, each division had to fit this" new child on the block" into its own demographic and established tag lines for the overall benefit of the whole CAFE. This was decidedly new territory for GM and was difficult to handle.  Add  to that the woes of early mechanical failure and customer disappointment;  this inflicted some damage on all the brands.

A major priority of product planning and engineering was to have the diesel experience be" transparent" to the owner/operator. The esthetics and dynamics of vehicle operation were to mimic as close as possible the gasoline powered versions. The only differences perceptible to the user were  to be the brief glow plug heat time before start and fueling from a different pump at the filling station. Otherwise, it was to be same as, same as, and "be sure to visit your local authorized GM dealer for regularly scheduled maintenance and service".  It didn't quite work out that way.

The divisions marketed the diesel option as an upsell, and the added cost definitely made it so.  Frequently, the diesel option was included among those of otherwise heavily optioned and accessorized units which drove the total vehicle cost even higher. People didn't like having paid a premium to have such confounding  and repeating problems of operation and reliability in otherwise wonderfully appointed cars, especially during the first 12 to 24 months of use. Many owners could not get away from their 5.7L diesel powered cars fast enough even though they were still under factory warranty and short of lease/purchase contract terminations.

The 6.2L engine family was completely new architecture and shared no cast components with any previous or other engine family. There was major engineering input from Detroit Diesel, and this engine was robust in areas critical for sustaining diesel combustion.  It did use conventional indirect injection employing the Stanadyne Roosamaster pump. This was a very successful diesel engine program and eventually allowed expansion of displacement and turbocharging in the later years.  This product was limited to C/K light,  medium duty  trucks,suvs and vans, cab/chassis conversions and military /civilian versions of Hummers. There were no passenger car installations of the 6.2L family of engines.

The 6.6L Duramax family of engines replaced the 6.2L series and has been very successful in the era of modern diesel emissions compliance.

A casualty of the GM bankruptcy was the 4.5L Duramax.  This is a revolutionary "reverse induction" diesel engine designed from scratch by GM Powertrain.  It was ready to go as an option in the GMT900 platform vehicles until GM had to do the Pelosi political pivot away from pickups and large SUV in order to get the bailout. Google "4.5 Duramax" for details on this astonishing engine from Wards publications.

The newest generation, foreign and domestic,  of passenger and light truck/suv diesel powered vehicles are technical marvels. 

       
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: James Landi on January 06, 2015, 10:04:03 AM
John, 

Interesting that you mention Detroit Diesel in your narrative.  Having owned two large boats, power by 871 Detroits, I became very familiar with these amazing two cycle, mechanically fuel injected, super charged engine platforms.  These engines enjoyed extraordinary long maintenance free service life, and could run up all day at 90 output without straining internal components.  ALas, they pushed unburned hydrocarbons out every pore, and as you clocked thousands of hours, they'd push out amazing clouds of smoke when cold started, much to everyone's discomfort and embarrassment.   GM had several "runs" at early 4 cycle diesels for marine conversions, but they were not reliable.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 06, 2015, 11:11:30 AM
The 6.2 / 6.5 'baby Detroit's' didn't really have much in common with their full size relatives.  They still had to try and keep the size and weight similar to the gas engines they were intending to replace.    Up till the Duramax series GM's diesel philosophy was always more in the direction of economy than power.   There is still a few companies doing marine versions of the 6.5.  Just like in the trucks it was just an alternative to a big block gas engine, basically a bolt in swap.  GM quit making the 6.5 in 2000.  At that time AM General bought the tooling and built their own engine plant primarily to continue supplying the military with the engines.  I think GM continued to buy them for the P series vans/trucks for several years.   I think the more current offerings for GM delivery van type of things are all Isuzu based.     The Duramax is/was a joint effort between GM and Isuzu.  Isuzu has its own line of diesel engines but just like the 5.7 and 6.2 GM wanted something tailored to fit the intended market so that is where the Duramax like came from.   The diesel Forums have been buzzing about the 4.5 for years and as far as I know its still not any closer to production.     

Interestingly about the time of the Duramax project GM bought half of VM Matori who primarily makes smaller diesel engines.   The assumption at the time was that GM was going to expand its diesel offerings world wide but apparently not much happened during the period they owned em.   I believe currently they are fully owned by Fiat.   Chrysler was using Matori diesel engines till the Mercedes deal at which point they switched to Mercedes diesels.   Guessing that deal ended with that partnership so the new Fiat group bought Matori to continue their supply of diesels.   Some non USA markets are primarily diesel so owning and producing your own diesel engine is important.   

I think currently the Cruise is the only GM car you can get in the USA and I think it came mid 14.   I believe all the major manufactures have announced several diesel options for the USA market over the next couple years.    I think Ford and Toyota are the only ones that don't have anything last time I looked.

I looked at the Cruise and just didn't like it.  I didn't find it comfortable or a nice ride.  Also didn't like the options you could get with the diesel.   Other than USA markets there were a lot more options including a wagon they just didn't offer em here. 

If the spread between gas and diesel stays over $1 per gallon that will likely slow down diesel growth here.  Apparently our refineries are tailored to produce mostly gas so with low production and high demand the prices stay high.    Most people don't realize they used diesel every day so most people don't care.    Almost all goods and services move by diesel or a close retaliative jet fuel so everyone is paying for the high prices now.   If more diesel cars got on the road and our refining process don't change I would think things would get even worse.   Guess its like most things these days, we can't win.       
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Eric DeVirgilis CLC# 8621 on January 06, 2015, 11:21:06 AM
A bit off topic here but I clearly remember diesel powered cars exhibiting far less rust than their gasoline counterparts.

I even recall discussing this with others who had also witnessed the same phenomenon back in the day. I guess the soot provided some sort of "undercoating" to the body and chassis...

Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: TJ Hopland on January 06, 2015, 11:56:47 AM
Only reason I could think if there would be less rust is you could not get em started or they were in the shop more often than their gas counterparts so they just didn't get the exposure. 

Seal wise there were identical to any other Oldsmobile and not much different than any other V8 of the era so they leak about the same as anything else in the era.   Some leaks like say valve cover gaskets are a lot more expensive labor wise to fix.   Imagine doing the gaskets on a gas engine with solid steel spark plug wires.   Lots more stuff to take off to get to em.   

You did get some soot out the tail pipe but I would think that would only effect things at the back.   Bumpers and truck lids rusted so bad in that era I can't imagine it helping or hurting.   Maybe helped because owners washed the cars more to get the soot off?
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Dr. John T. Welch on January 06, 2015, 04:04:41 PM
Eric,

Thanks for your astute and insightful observations concerning a seeming
corrosion differential  between diesel and gasoline versions of this era GM
vehicles.  I say "seeming" because I have no empirical evidence to reinforce my
similar observations.

I attend many large wholesale, municipal, insurance salvage and private fleet 
auction sales.  Typically, the vehicles are not detailed or otherwise prepped
prior to sale.  It's an "as is where is, what you see is what you get"
experience.  To my eyes, diesel powered passenger cars and light trucks stand
out for reduced corrosion damage.  The differences are subtle but significant. I
have no way to control this observation for the effects of different climates.
In my experience,  Mercedes products are standouts for these comparisons,
especially among the big S series sedans. 

Several acquaintances store diesel powered vehicles at seasonal homes for summer
use. The storage conditions are very favorable, always enclosed and usually
heated,  and the vehicles are properly prepped for protracted periods of non
use. The garage areas where the vehicles are stored always emit the typical
diesel fuel aroma, and over time a very thin fog develops on the interior panes
of the building windows and on all of the glass surfaces of the vehicles. This
film can be wiped with a finger and "felt" as a finger wipes the body
surfaces... bingo, your finger smells of diesel fuel.  The same phenomena can be
observed around the  diesel fueling areas of truck stops. All the pumps, hoses,
towel dispensers, squeegees and card readers have and impart  diesel odor in the
absence of visible liquid fuel.  This is not the case in gasoline dispensing
areas.

I think you are right in that diesel vehicles seem to generate their own "micro
climate" as it relates to corrosion inhibition. Even after 12 months had passed
since I stored a diesel vehicle in my garage, I could still detect a faint
diesel aroma there, and many items stored would leave the slight odor on my
hands after touching them.



Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Eric DeVirgilis CLC# 8621 on January 06, 2015, 04:48:48 PM
Thanks John for posting your experience & observations regarding the "non rusty diesel" phenomenon.

Back in the day whenever a relatively clean older GM model was spotted on the road, "Must be a diesel" or "Too bad it's a diesel" was the common refrain.  ;D

It's reassuring to see that I am not the only one on the forum who has witnessed the odd - but decidedly - above average condition of diesel vehicles.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: Big Apple Caddy on January 06, 2015, 07:34:37 PM
Quote from: ericdev on January 06, 2015, 11:21:06 AM
A bit off topic here but I clearly remember diesel powered cars exhibiting far less rust than their gasoline counterparts.

I had never heard this theory before.

My experience growing up was that the GM diesels tended to be higher optioned, upper trim models e.g. not a base Cutlass but a loaded Cutlass Brougham, not a base Century but a loaded Century Limited, not a base Bonneville but a loaded Bonneville Brougham, etc.  Not always, but often.  Early on, the diesel engine alone was also a pricey option.  I don't know if historical sales data would support my "loaded up" observation but if so, perhaps the diesel cars were simply taken care of better, stored better, etc. because they were more likely to have had comparatively wealthier owners.

I also think they may have been used less in winter or in snowier climates due to potential cold start issues.
Title: Re: Anyone else currently own a 78-85 Cadillac diesel?
Post by: bcroe on January 06, 2015, 09:26:31 PM
Quote from: ericdevCorrect, externals are the same.
Internals are very different - and the diesel weighs 500 lbs more than the gasoline version.

The diesel cars definitely weighed more, I don't know how much.  They had an extra battery, and
a really big starter.  We were just talking about the heavier torsion bars used in the diesel Eldos. 
Fortunately in addition to all the above, the ENGINE was not 500 lb heavier, or the whole scheme
would have been unworkable.  Complete engines or their parts are here for examination. 

The small block Olds got a heavier crank of the identical stroke, and big block mains.  A heavier
timing chain turned both the cam and the injection pump.  This required the front seal to be
moved forward a fraction, and a stronger ring gear met the starter.  The oil pump drive was
identical, but a vacuum pump was plugged in the same position since the HEI wasn't used. 
Cylinder walls though in the identical position, were heavier.  Rods & pistons were redone. 
There was the injection pump instead of a carb, and the heads were totally new.  However they
used the same pattern, so experimenters had no trouble bolting on gasoline heads to creates a
supper strong gas engine out of an old diesel.  Put back the HEI, gas fuel pump, etc.  Bruce Roe
Title: 5.7 L diesel coda
Post by: Dr. John T. Welch on January 06, 2015, 10:35:10 PM
In '87 I made a killer oval track Olds 350 using a diesel short block and the big valve 403 heads. Joe Mondello made a billet plug for the injection pump hole in the front of the block. Roller cams for this engine were scarce at that time, but Crower stepped up the the plate  with a roller version of the W-40 stick.  The flat top diesel pistons gave 11.5: 1 compression. We could never kill the engine and nor could the three subsequent owners. The reciprocating assembly was heavy but bulletproof.  The keys were the big block main journals,  the beefy diesel rods, and floating wrist pins. As I said earlier, the vibration harmonics just didn't let this work for durable and reliable diesel combustion.

Sorry for this not being Cadillac, but fun nonetheless.

End of this topic for me.  'Nuff said.  Thanks to everyone.