Awful Mystery Problems

I bought a 1998 LeSabre Custom, roughly 65k, in September. It has a 1999 engine with similar mileage because the first owner drove around with cracked manifolds for a long time. A very honest used car salesman who has sold my family several great vehicles thought it was in good shape. On day one, I had a bit of an oil pressure issue. A bit of thickener solved that temporarily. I used 40 weight thereafter and was fine. The check engine light was on within a few weeks. I took it in. Mechanic 1 lectured me about my gas cap. He assumed it had been loose. He sent me on my way. It came back. He changed an O2 sensor. He said that the others would also fail soon, but that I should wait until the check engine light stayed on. It came on again soon but did not stay on.

It was on briefly, once in a while, through winter and spring. The car sometimes smelled like coolant. When summer came, it sometimes also smelled like burnt rubber after a long drive, but a reputable mechanic in the town where I was doing research could not replicate that and said it was fine. The check engine light finally came back on to stay around Independence Day. The code indicated the MAF. I changed that. It went off for a couple of days and then was off and on some. On July 7th, I decided to take it in. That afternoon, it would crank but not run. There was a deposit of motor oil Mechanic 1 had been condescending, so it was towed to mechanic 2. He had a better attitude. He reattached a vacuum hose, changed some gaskets and the PCV, put in an OEM MAF and charged me very reasonably. The oil pressure was great with a lighter oil. Within a few days, the check engine light was back on. He tested all the O2 sensors, which were fine, checked and cleaned the injectors, which were fine, and changed the upper intake manifold. Within 24 hours, the light was back on and I was smelling coolant again. He took it back and changed the lower intake manifold at no charge. He gave it back yesterday and said he was going to think over the weekend about why it was still running slightly lean. The light is back on. The car nearly overheated today. The oil pressure was almost bad enough to turn the light on. I smelled coolant and, a couple of times, maybe the faint odor of burnt rubber. The oil has a slight, rusty tinge. The oil leak inside the engine compartment is back.

Does anyone know what is going on? Between the three shops that have worked on this, it has confused at least seven mechanics. School is starting. Whether I keep this vehicle or get another, I need this resolved. My senior year of college is about to start. It is impractical for me to live in my housing for the year without a car. Can it reasonably be saved? It has already burned through at least $2200 in repairs, around half its value. Should I go back to the shop or find an exorcist?

Oil leak, coolant leak, overheating, contaminated oil…$2200 already spent on repairs…this car is not worth wasting any more $$ on.

Sell it as is and get yourself a reliable basic used car like a Honda Civic or Toyota Corolla. For the $2200 in repairs you could have bought one already.


GM has had many intake problems . . . gaskets, the manifolds themselves, etc.

If you tell me exactly what engine you have and the year of the engine, I will post some (hopefully helpful) documents

If you used straight 40 weight oil in the engine, the engine is toast.

Each time the engine was started cold in the winter, the oil was too thick to provide the proper lubrication of vital engine components and caused rapid wear of those components.

I would suggest that the next vehicle you purchase, that you should read the owners manual and use the proper weight of oil the manufacturer recommends.

Because using a thicker oil to prevent the oil light from coming on is just masking a bigger problem.


-What exactly were the codes that were coming up when the check engine light was on?
-When you say the oil has a ‘rusty tinge’, does it look like a milkshake? If so, you are getting coolant in the oil, which will quickly destroy your engine bearings (and might have already), leading to low oil pressure.

I’d have the cooling system pressure tested to see if you have a head gasket or other breach allowing coolant into the oil.

My vote is for selling this car and being done with what is quite likely going to be a hacked up, neverending headache; and I’m normally not the type to recommend this kind of thing.

The problems started with your first few sentences about a very honest car salesman (who may know nothing about mechanical things) telling you it was in good shape and having a bit of an oil pressure problem as you describe it on day one. The addition of an oil stiffener or heavier oil cures nothing.

@Tester, the engine, as far as anyone knows, is a 1999, the usual 3.8L V6. I took a chance on an American car because I needed something, the mileage was low, and the price was right. The dealership was honest, and everyone who looked at it thought it was fine. I liked it, but I regret having anything to do with it now. It may have to go. I will be more cautious of American cars and cars with used engines from unknown sources in the future.

Sounds like you got a little unlucky on that purchase, sorry. I think that car is usually thought well of in general. In fact I think I heard the other day the new Lasabre is rated highly by somebody or another.

Back to your problem. One thing you could do is check Consumer’s Reports Used Car Guide, see what they say about that year as a used car. They’ll rate the various systems. Cooling system. Fuel system. Major engine. Minor engine. etc. If a problem is noted with the fuel system for example, that may provide a clue what is wrong with your car. Give you something to work with anyway, what other owners of this car are saying has gone wrong for them.

Beyond that, probably if it were my car I’d do a compression check, and I’d have a shop do one or more of their pressure tests to see if there are any unseen leaks, like head gasket leaks. They might suggest a chemical test to test for exhaust gasses in the coolant too. Or coolant in the oil. Or oil in the coolant. That info plus the DTC codes from the ECM would tell me what to do next. And that might include selling the car.

The fact that it’s an American car, is a Buick, and has a 3.8 engine actually has nothing to do with the problem.

The problem was created by the previous owner, not GM, and many used cars are sold by “puffing” them; which is essentially legalized lying.

The simple fact that a 98 model car already needed a used engine by roughly 65k miles would have steered me away from it no matter what this honest and reputable dealer or salesman had to say about a car that they never owned or had driven for any length of time.

Good point @ok4450 . 65k on a 1998, something seems suspect. Me, I wouldn’t buy a 1998 if it only had 65k on the meter, unless there was a plausible explanation. If that’s the true mileage, then the car wasn’t driven frequently enough, and that leads to all kinds of problems. Seals dry up, the exhaust system corrodes, the electrical system gets the heebie-jeebies, near every start is a bone dry start, so the piston rings take a beating, the fuel system clogs up with varnish, the oil with sludge, and the brakes, I’m not even gonna talk about the brakes. Did the prior owner explain why this car’s mileage was so low?


Last year I bought a 1999 Mercedes-Benz for my mom

It had 62K at the time . . . guaranteed


No odometer rollback

No undisclosed accidents

The guy was not trying to hide anything

If anything, my trained eye could tell that the car had been well taken care of.

I’m just trying to say that not every low mileage older car is a potential nightmare

If you used straight 40 weight oil in the engine, the engine is toast. -

What? 40 is a very popular weight.
I use 0w-40 all the time. or 5w-40.
Or do you mean 40w-40 is too thick at startup?

How has this guy not posted CODES?

I have a '97 Jeep Grand Cherokee Loredo.
After driving for a while and stopping, the car wont re-start and the shift assembly freezes. I can’t even push in the shift button to get her into neutral. After 15 min’s to an hour the shift frees up.

I have already spent a considerable amount of money on Throttle body service, Neutral safety switch, various electrical work…

I am now told it needs a new shift assembly

Has anyone else experienced this problem and what is the correct solution?

Thank You:


Never seen any oil with that designation. If it’s not multi-viscosity oil then it’s called straight weight. I.E. 40 weight. or Straight 40.

And 40 weight would probably be way too thick for start-up when temps get below 70.

@LiausHoratuis … suggest to post your problem in a new thread. You’ll have a better chance getting replies. See that red box at the top right of this page? “Ask a Question”. Click there.