View Full Version : Listing of PROBLEM engines...

Kent Dorsey
10-23-2014, 11:13 PM
I was discussing problem engines with a bus mechanic the other day, who said the 2007 International school buses were a nightmare. I am aware of some mid 2000 era Ford Navistar engines that have had issues. I know there are some Cadillac engine issues of '83-'84 vintage...
I am hoping we can compile a list of problem engines here... and please no, "I've had a blah blah blah '98 Northstar that has 209,000 miles and I would drive it to Bangkok..." type stuff... there are exceptions everywhere. I am talking about the engine issues we can all agree exist and a fair warning needs to be made when thinking of a purchase of a car (or truck) of this era.
Please help me fill in the blanks on any of these I mentioned in the first paragraph...
I'll start...
1997-2002 Cadillac Northstar engines
(blow head gaskets, blown engines, etc...)

Mitch Fiandt
10-24-2014, 09:12 PM
1999 North Star engine eagle coach used 3 quarts of oil between changes started at 60k miles

Pat Post
10-24-2014, 10:55 PM
1999 North Star engine eagle coach used 3 quarts of oil between changes started at 60k miles

My '97 needed a new engine due to a cracked block at 87k.

Shawn Koenig
10-24-2014, 11:23 PM
Would like to know more of the '83-'84 Cadillac engine issues. I have an '83 myself. It wasn't in '82? Just got one of that year that is going to a friend, so any help is good and appreciated.

Kurt Arends
10-25-2014, 12:04 AM
All '82-'85 Cadillacs, with the exception of the '82-'84 Cadillac commercial chassis, came with either the HT4100, or diesel engine. The HT4100 continued through '86 on the FWDs.

John Royark JR
10-25-2014, 12:18 PM
All '82-'85 Cadillacs, with the exception of the '82-'84 Cadillac commercial chassis, came with either the HT4100, or diesel engine. The HT4100 continued through '86 on the FWDs.

The 4.1 was also used in 1987. Ive never had any problems with them, but Ive heard the stories.

Patrick J. Martin
10-25-2014, 07:34 PM
I also had a Cadillac 4100 motor, and also had no issues with it. Very underpowered yes, at least in my application of a rear drive six door limo, but mechanically it was fine. The poor reputation they received was because the design apparently tended to blow head gaskets internally, allowing the coolant and oil to mix, and then blowing the motor if it wasn't caught. I remember my owners manual calling for oil changes every 2500 miles rather than the more common 3000 miles, and I remember it calling for the use of radiator sealer tablets whenever the coolant was changed. Most people neglect their car maintenance and usually it has no serious effect, but in the case of this motor, it could be fatal.

Another Cadillac motor from the early 1980s that I'm sure someone will bring up as being a problem engine is the V8-6-4 from 1981. This is a motor that there is a lot of misbelief about, even within the Cadillac community. First of all, the V8-6-4 was not a unique motor. The V8-6-4 was the Cadillac 368 V8 fitted with a unique fuel injection system, but the 368 itself existed in carbureted form from 1980-1984. The V8-6-4 fuel injection system relied on a speed sensor in the transmission. All eight cylinders would be active at low speed, then two cylinders would stop receiving fuel at moderate speed, and four cylinders would stop receiving fuel for highway cruising. The problem was that the technology wasn't sufficiently developed at the time to allow for this to work as it should have. Even when the system was working properly, there was a brief but noticeable lag as cylinders went inactive or became reactivated, which the traditional Cadillac buyer found annoying. More serious malfunctions involved cylinders going offline too early resulting in horrendous acceleration, or even of fuel delivery being cut off entirely. Since the system was all based on speed sensor readings, simply unplugging the transmission sensor allowed the motor to perform as a full time V8.

Then there was the infamous GM diesel, which was available in Oldsmobiles, Buicks, and Cadillacs. The GM diesel was a rush program to get into production, and as such was just a modified gasoline motor. The problem was the converted gas motor couldn't withstand the high compression that a diesel required, and they would blow themselves apart.

Take three major engine public relation disasters, add in the Cimarron embarrassment and the Chevmobile scandal, all taking place within short order of each other, and sadly its not hard to see why GM and the American auto industry slipped so badly in public confidence at the time.

Joe Rackov
10-26-2014, 10:59 PM
Well, a few "vintage" engines issues:

305/350 Chevrolet engines from about 1975 to 1979 had camshaft faillure issues due to improper heat treating.

Same engines/years, a knock on cold engine startup. Various reasons were cited by GM for this. Fix was selective fit front main bearings. I forget the sizes but there were several. Technician would mix and match sizes to get the desired clearance.

Same engines/years. When tearing these down there were some odd sized bearings used as main journals often were not ground to the same size on all. No selective fit service parts, standard and .010 IIRC, warranty fix was to replace crankshaft with a new one with all standard sized bearing journals. Now if they could do this for service parts why not production parts?

1965 to 1972 Pontiac V8 engines had a nylon/aluminum camshaft sprocket that would shed the nylon and jump time. Usually no valve damage. Saw some at a couple thousand miles fail. I shucked a timing gear on my Ram Air 3 engine at about 90K. We used to do so many under warranty that to this day I still remember all the part numbers involved. If you ever have this happen, be sure to drop the oil pan and clean out all the debris. Otherwise the oil pump will pick up the pieces and they wiil get stuck in the oil pump pickup screen thereby restricting oil to the bearings.

Strange thing, Chevrolet used a similar gear but it was not as problematic with them.

While on the subject of Pontiacs, if you replace the water pump be sure to remove the metal divider plate between the timing cover and the old pump and reuse it. If not reinstalled YOU WILL OVERHEAT, you will not pass go, you will not collect two hundred dollars. Also, 1969 and later use a insert tube on each side between it and the timimg cover. Be sure they are there and the seals are good. Also never run a Pontiac without a 50/50 coolant mix. Timing covers will corrode due to electrolysis.

Pontiac parts interchangeability can be a little tricky, ask a professional (or myself) before changing heads or intakes or timing covers.

Oldsmobile V8's, 307/350/403/455 and the infamous 350 Diesels had steel rocker arms with aluminum "stands". Clatter noise in the valve train area can be from wear of the stands. Usually higher mileage cars or engines that have not had the oil changed regularly.

All I can think of for now.

Joe Rackov
10-26-2014, 11:18 PM
Forgot another one with the first generation GM HEI distributors fron 1975 on.

If you pull the distributor cap and see a Delco Remy black plastic rotor, this is an original equipment part. Service replacement parts were a white or ivory colored and were a different (better) quality part.

If the four pin electronic module is a white one, REPLACE IT. Those were original equipment 1975-6 era and were failure prone.Again this is only valid for Delco Remy or GM labeled parts.

If you have a miss or stallout off idle with an HEI a quick and dirty test is to remove the vacuum advance hose and retry the test. If it goes away take a ohmeter, unplug the pickup coil (two wire yellow connector to the module) and move the wires around. Watch continuity on the meter, If it goes open or the needle moves, replace the coil. Those fine wires flex each time the vacuum advance moves thereby moving that coil for the distributor advance.

One other trick you can use at your own risk. On early GM C3 (Computer Command Control) with a carburetor. If you have a performance problem that defies all tests unplug (while not running) the four wire connector that goes into the distributor at the bottom. If you restart the car and the problem kind of goes away you have isolated the problem. The early cars will run off the module without the computer connected but not real effeciently. If you have a full blown computer failure on one of these cars doing this will also allow you to "limp home"

Reason I said "at your own risk" is this was not a approved GM test procedure and connecting and disconnecting any computer control part can voltage spike damage it. We only used this procedure when all else failed or we had to get a car in to the shop and it was near impossible to get a wrecker to pick it up.

Joe Rackov
10-27-2014, 06:03 PM
Small block Chevrolets from the late 70's to about 1982 may have a oil consumption problem and oil fouled spark plugs on the right bank, mainly cylinders 4 & 6 and sometimes 8. It could be that the intake gasketshave failed due to heat from the EGR valve allowing oil to be drawn in the intake runners in the head. Subsequent intake gaskets were more heat resistant.