1984 Eldorado

[Troy Alexander]

Can anyone in the Club please inform me if the 1984 Eldorado Biarritz
came in any other Engine options than the 4.1 Litre? I am aware of
the Diesel Engine. Were either the 4.5 or 4.9 Litre available in that year?
This Car will soon be available for sale. It has only 19M original miles.
Owner unsure what Engine he has?

if anyone knows this, please contact me as soon as possible.
Can anyone tell me if the 4.1 Litre had any longevity before trouble starts?

Thank You.
Troy
Cadillac Club
E-mail: troyala1email addresses not permitted
Office: 310 822-2388 or Cell: 310 701-5567

[Dave Shepherd]

4.1 was was the only 8 cyl. gas engine.  Generally this was a troublesome engine with camshaft failures, #1 main bearing noises and various leaks. I was in on the ground floor trying to keep these running back then, earned my keep.  LOL  Lots of major work was done under 50k!

[TJ Hopland]

84 there were only the 2 choices from the factory.  Gas HT4100 and Diesel 5.7.    The 4.5 and 4.9 were later engines based on the 4100.  There were 2 different 4100's an longitudinal (RWD and Eldo / Seville) and then the transverse that went into some of the 85's and all the 86+.  The 4.5 and 4.9 was only made transverse.  I have read if someone was real ambitious they could swap some of the internals from an early 4.5 to a early 4100 but dont imagine that was a common thing.  Due to the electronics, weight, and not sharing dimensions with any other engine swaps were not extremely common, most people just gave up on em.   The diesel however had minimal electronics and did share all its external dimensions with the gas Oldsmobile V8's so swaps were very common on those.  The fuel gauge on the dash most likely would still read 'diesel fuel only' and it would most likely have a carburetor on it.   If it was originally a HT4100 car it would have had the fuel monitor trip computer on the dash.  Most of the swaps I have seen they left that dead in the dash.

8th digit in the VIN number is the engine.  The Diesel was N.  HT4100 was 6.       

Mid 80, 81, 82 those could be had with the Buick 4.1 V6 4bbl.  80 was the DEFI 6.0 or CA emissions Olds EFI 350.  81 was the infamous DEFI 6.0 V8-6-4.  79 was the Olds EFI 350.  The 4100 came out in 82.  The Riverias and Toronado had a Buick 3.8, 4.1 V6 or Olds 5.0 V8.  In theory any of those cars could have been engine donors.  85 was the last year for the body style.  Other engines would be unlikely because of the unique FWD design.     

[Eric DeVirgilis CLC# 8621]

"Is there any longevity of the 4100 before trouble sets in?"

In a word, no. They can develop problems at any time without warning. However, those who maintained their 4100s as prescribed were less likely to have issues than those that didn't. On the bright side, some improvements were made throughout the span of the 4100 years and 1984+ were more reliable than the 82/83 in my experience.

Re the 1981 V-8-6-4: Mechanically, this engine was as robust as any V-8 Cadillac ever made. It was the early computers and wiring harnesses that gave runability problems which had nothing to do with the mechanical integrity of the engine itself. These issues had been addressed and sorted long ago. Additionally, the V-8-6-4 was the last for the THM-400 which is far superior to the metric 4-speed trans that was fitted in HT 4100 cars.

[TJ Hopland]

Yesterday I saw a 84 Toronado  21K miles original diesel been swapped for a gas so you never know........

[Eric DeVirgilis CLC# 8621]

Yesterday I saw a 84 Toronado  21K miles original diesel been swapped for a gas so you never know........

If that diesel was healthy, that was not a wise thing to do.

[TJ Hopland]

Story was engine replaced 3x under warranty and after the 3rd one quit it got parked and it then sat till one of the grand kids took a slight interest in it and did the swap but now he runs the 'tuner' cars and is trying to sell the Olds for a lot of money to pay for his new toys. 

[Davidinhartford]

If I found a mint 82-85 Eldorado I had to have,  I'd look into swapping in a gas motor from a 79-85 Riviera or Toronado.

[waterzap]

The Riviera and Toronado had an Olds motor, similar to my 76 Seville if I am correct?
Dont think there were too many problems with those motors.

[TJ Hopland]

Riv's tended to have V6's.  79 80 Toro would have been the 350 which was the same as the Seville but no EFI.  81 I believe was the start of the Olds 307.   I dont think they ever put the Olds 260 V8 in those cars.    The 307 was the motor that went into the 85-90 Broughams.  It was nothing special but it was all cast iron.  Always had a computerized 4bbl carb. 

[76eldo]

Here's a link on complete swap info on replacing an HT4100 with something else:

http://www.radar58.com/eldo/swap.html

There is NO direct bolt in swap, you need to be a bit of a hot rodder to pull this off correctly.

Too bad my 81 Eldo with all of the proper components and a great running 70K drivetrain went to the crusher.  I tried to sell it here for the same $400.00 the junkman gave me.  Just didn't have any more room to store the car.

Brian

[Eric DeVirgilis CLC# 8621]

   The 307 was the motor that went into the 85-90 Broughams. 

1985 Broughams had the 4100; 1986-1989 Broughams had the 307 exclusively. The 1990 Brougham was standard with 307, 350 FI optional.

GM Diesels have developed a "cult" following lately and are bringing similar or greater money than their gasoline counterparts. Very different from years ago when you couldn't give one away. 

[bcroe]

Some of us figured out diesels 30 years ago.  Get the car for next to nothing, low
miles.  Put in a 403 Olds, never get called for emission testing.  Fast car, heavy
duty electrical, extra sound proofing was SO QUIET, the big air cleaner contributed
to performance, 4 extra gallons in the tank with no unleaded only fuel restrictor. 
My 80 Delta with switch pitch & stock 403 would do 91 mph in the 1/4 mile, sure
surprised a lot of people.  For those still driving a diesel, get a switch pitch trans; it
positively transforms the car.  Bruce (has 3 diesels) Roe