Late 70's to Late 80's Engines to Avoid or Not to Avoid

Started by Joe Vastola, September 11, 2016, 06:56:25 PM

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Joe Vastola

I'm starting to consider my next classic Cadillac purchase.  Years wise I'm focusing on the full size models in the 1977 - 88 range.  I'm only interested in the big Cadillac ride so CDV, Deville, Fleetwood are all good options. 

I have read much about the quality of the late 70's engines and about the problems with the HT-4100.  Unlike my 49, I expect to drive the car quite often.  Maybe daily since it will have a/c.

Besides the HT4100 are there other engines to avoid?  What years/engines/displacements are the most dependable?

Scot Minesinger

There were some improved versions of the 4.1, such as the 4.5 and I would avoid it too and all front drives 1982 and after.  On late 1970's to late 1980's I would consider:

Eldorado 1979 and 1980.

Seville 1975-1979 (1980 might be OK)

DeVille/Fleetwood 1977-1980

(I left off 1981 due to 8-6-4, but that can be deactivated and then you have a 368 - same as 1980)  However that 425 engine from 1977 thru 1979 I super nice.

Brougham 1986-1992 (with 5.7 if available)

Also the Broughams from 1993-1996 are great too.

Any 1970's or earlier you cannot go wrong.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Barry M Wheeler #2189

The Buick V-6 available in 1981 (which I have) has been quiet and dependable (80K) and I read a favorable review not too long ago elsewhere. Seville/Eldo.
Barry M. Wheeler #2189


1981 Cadillac Seville
1991 Cadillac Seville

Eric DeVirgilis CLC# 8621

Curious as to why the cutoff at 1988...? The full size RWD Brougham is essentially the same car from 1977 - 1992, although with about 10 different driveline combinations throughout that period.

For maximum reliability I would agree with Scot's choices but I would also suggest sticking with carbureted 425 only (77-79), 368 of 1980/1981. V8-6-4 is a fine engine. 5.0 (307) Olds powered Brougham from 1986 - 1990 is okay but dreadfully underpowered. Also recommended are 5.0 (305) & 5.7 (350) Chevy powered Brougham from 1990 - 1992.

* Note that 305 Chevy was in 1991 & 1992 only; 1990 was standard with the 307 Olds and the 350 Chevy optional. 
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

Greg Powers

The only engine that I did not see listed  so far was the infamous "diesel" option. These are still around in a few Cadillacs from the early 1980's, especially Sevilles, but should definitely be avoided at all costs. Some were actually swapped out for gasoline engines by the dealerships after numerous problems.
G.L. Powers>1954 Series 62 Sedan/1958 Fleetwood 60 Special-sold/1963 Series 62 Convertible-sold/1970 Fleetwood Brougham-sold/1994 Fleetwood Brougham/1971 Sedan Deville-sold/2000 Deville-sold/2001 DTS-sold/1976 Eldorado Convertible-sold/1983 Coupe Deville-sold/1990 Allante-sold/1990 and 1991 Brougham deElegance-sold/1992 Brougham-sold/Always looking!

Joe Vastola

#5
This is exactly the information I was hoping to get and still leaves me with a good long list of alternatives. If the message is that the Brougham still had the Cadillac ride through the full model run, then it's an add to the list. 

Beyond the power plant, are there any other model or year mechanical considerations, fit and finish considerations or pluses and minuses that should be applied as additional filters or preferred options?

Maynard Krebs

I had a number of RWD GMs from the 1980s with the Olds 307s.   Half of 'em self-destructed, and those that didn't.. were dreadfully weak & slow.   Thus, I say.. avoid them.

Scot Minesinger

Eric,

I know that in 1982 the full size RWD Cadillacs were equipped with the 4.1 V-8 I hate so much.  I think this ran until 1985, and then in 1986 you could get the 5.0 in Brougham.  I cut off in 1988 because I think that was the first year of the 5.7 option in a RWD Cadillac.  Although the 5.0 engine in the 1986 thru 1989 or so was not terrible, why go there if a 5.7 is available.

All,

I forgot about the few V-6 Cadillac engines of the 1980's, and I would stay away from them for collectivity purposes, many said during that time, my Grandmother included " It is a V-8 or nothing!" when they tried to sell her a V-6.

On the diesels, same thing collectability, would avoid them too.  However, my Father drove a 1980 GM Diesel and he liked it so much he purchased another and both drove over 150k miles trouble free - understand this was rare.  You can do nice things with diesels now, one of our local guys owns a 1981 Seville diesel and he has had the performance improved, and is faster than anything else Cadillac offered at the time.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Eric DeVirgilis CLC# 8621

#8
Quote from: Scot Minesinger on September 24, 2016, 08:48:55 AM
Eric,

I know that in 1982 the full size RWD Cadillacs were equipped with the 4.1 V-8 I hate so much.  I think this ran until 1985, and then in 1986 you could get the 5.0 in Brougham.  I cut off in 1988 because I think that was the first year of the 5.7 option in a RWD Cadillac.  Although the 5.0 engine in the 1986 thru 1989 or so was not terrible, why go there if a 5.7 is available.

Scot, I was referring to statement posted by the OP in the thread opening:  I'm starting to consider my next classic Cadillac purchase.  Years wise I'm focusing on the full size models in the 1977 - 88 range.

Engine use in RWD models from 1986-1992 as follows:

1986-1989: 307 Oldsmobile 4bbl standard engine.  No other engines available.

1990: 307 Oldsmobile 4bbl standard; Chevrolet 5.7 Liter FI optional.

1991 & 1992: Chevrolet 305 FI standard; 5.7 Liter FI optional.

Buick 4.1 Liter V6 available [mid year] 1980 - 1982.

Thanks.
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

Scot Minesinger

Eric,

Thanks I was never quite clear on the year and options of engines (305Chevy/307 Olds vs 5.7 Chevy between 1986-1992).  Just knew the dark period from 1982-85 when the 4.1 was installed in RWD Cadillacs, and that 1986 thru 1992 worst case 5 liter GM engine in RWD Cadillacs.  You would think 1990-1992 that the 5.7 would have been a popular option.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Eric DeVirgilis CLC# 8621

Quote from: Scot Minesinger on September 24, 2016, 09:23:22 PM
Eric,

Thanks I was never quite clear on the year and options of engines (305Chevy/307 Olds vs 5.7 Chevy between 1986-1992).  Just knew the dark period from 1982-85 when the 4.1 was installed in RWD Cadillacs, and that 1986 thru 1992 worst case 5 liter GM engine in RWD Cadillacs.  You would think 1990-1992 that the 5.7 would have been a popular option.

Scot, in 1991 the 5.0 Chevrolet 305 FI replaced the 307 Oldsmobile as the the new standard engine in the Brougham. Performance of the new 305 was far superior to the 307 and not that different than the 350, perhaps making the 5.7 not as necessary as it had been in 1990.

It is a shame there were no engine options from 1986-1989 because these were even more gutless than a 4100. But then, GM had been trying to pull the plug on the Brougham every year after 1984.
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

bill06447

I sold these new from 87-92. The 5.7 was a limited availability option due to fuel economy regulations; the order window was narrow, and many times the car you ordered with 5.7 showed up with 5.0 anyway. When you tried to swap with another dealer to get a 5.7 they had, they sometimes wanted 2 for 1 in trade, usually FWD DeVilles rather than the 5.0 Brougham you had on hand, as those were far superior sellers.

Bill

T J Lankes

Treat yourself to a '79 and shoot for the heritage of a genuine Cadillac Clark St. unit, IMHO.

The high quality 425 CID engine, derived from the 472/500, is great as is the ride and quiet interior.

Best of luck.

   

Scot Minesinger

Eric,

Have to disagree on your comparison of the Olds 307 and Caddy 4.1 V-8's.  The 307 Olds engine is better than the Cadillac 4.1 V-8 engine.  I could live with a 307, but no way a 4.1.  This is from recent personal experience.

Just this year I worked on an Olds 307 engine and the year before a 4.1 powered RWD Cadillac.  The 307 was much better than the 4.1.  It is unlikely that you could write anything that would change my mind on this based upon recent driving experience.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Eric DeVirgilis CLC# 8621

Scot, there is no disagreement the 307 was a better and much more reliable powerplant than the 4100 it replaced. But it was hardly a powerhouse by any stretch of the imagination and I have personally found it no better than a 4100 in terms of off-the-line acceleration. Final gearing may well account for this, I cannot say.

Regardless of the relative performance figures between the two, it is a fact that Cadillac received an awful lot of complaints about sluggish acceleration from Brougham owners which is why in 1990 the 5.7 Liter was finally added to the options list, and in 1991 & 1992, the 307 was dropped altogether and replaced by the Chevrolet 305 standard engine giving the RWD model the best acceleration it had since 1979.

Thanks.
A Cadillac Motorcar is a Possession for which there is no Acceptable Substitute

Scot Minesinger

Yes agreed 307 was better than 4.1, but no powerhouse for sure.  As the current President of Cadillac said recently, "Cadillacs should have a sense of power."
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

bill06447

The 307 was dropped not because of any perceived problems, but because of GM's reorganization of their engine production. No more Buick/Olds/Pontiac engines just GM Corporate a/k/a Chevy engines....oh and the 4.1 heritage engine

Bill