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Dead Buick LeSabre

Dad was driving his '98 Buick LeSabre in stop-and-go traffic. The overheat light came on. He turned on the heater and suffered, and the light went off. Got home. An hour later he took the car for an oil change. They went to top up the fluids and it was 2 gallons short of coolant. They topped it up. Drove home. Later that evening the car was driven just a few kilometers and the overheat light came on again. Got to the destination a few minutes later. Went to drive home and the car wouldn't start. Every light on the dash is on. I drove out there with 5 gallons of water. I put about 3 gallons in the radiator and overflow tank. Car still won't start.

A guy I work with was a dealership mechanic for 15 years and he says these cars have a plastic intake plenum that melts and warps causing fluid leakage, and best guess is that's what happened when the car was overheated. Okay. Forgot to ask him why the car is still not starting, even topped up with water. Any thoughts?

Reply to
Mike Graham
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Mike Graham wrote in news: snipped-for-privacy@zippy.metalmangler.com:

See the link in a post a bit earlier titled 'GM Lemons'. The intake manifold leak most likely has filled the engine cavities with water/coolant. It is possible, if it got into a cylinder, it has hydrolocked. It is also possible the camshaft has broken.

Reply to
Anthony

"Mike Graham" wrote

It won't start, because the cylinders are being flooded with coolant. I would advise you to not attempt any more starts, but get it towed to a competent repair shop and have the upper intake plenum removed. I'll bet that this is what they will find:

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You need to have the upper intake plenum replaced, probably a new set of spark plugs will be in order, change the engine oil and filter "before" the engine is restarted.

If you plan to keep the car for a while, I would suggest that you also change the lower intake manifol to the updated design. Here are the part numbers you will need.

a.. Lower Intake -- 24508923 b.. Upper Intake -- 17113136 (includes necessary upper intake plenum gaskets) c.. Lower Intake Gasket -- 12537197 Hope this helps.

Ian

Reply to
shiden_kai

So if I understand correctly the new plenum is unchanged but the lower intake manifold has been redesigned to cure the problem permanently? Bob Knutson

Reply to
Bob

My wife has a 96 3800. Do I have to worry about this ?

Reply to
Akacguy6161

Thank you for the reply. I checked the dipstick very, very carefully for any signs of water before I tried to start it, as I was thinking, at the time, that perhaps the head gasket had blown into the cylinder when it overheated. There was no sign of water. The engine cranks normally. The check engine light comes on as soon as the key is turned to 'on', and it stays on. This makes me think there is something else going on. The plenum may well be warped, I don't doubt that, but I think something else happened to cause the no-start situation. I don't know of any codes that would be set that would cause the car to not start at all. Are there any?

Reply to
Mike Graham

Reply to
Finite Guy

Mike Graham wrote in news: snipped-for-privacy@zippy.metalmangler.com:

If it drank 5 gallons of water, that water went somewhere. I suggest pulling the plugs (all of them) and doing a compression check. If the water got into the cylinders it could have caused the plug insulator to crack and break off due to thermal cooling. Compression test will also tell you if you have valve problems. You might also start looking for melted sensors and other electronics. With any regard, you are still going to have to pull the engine down to see where that water is going.

Reply to
Anthony

Undoubtedly. If the plastic intake plenum is warped then the water would have ran out the front of the engine and onto the ground.

Reply to
Mike Graham

"Mike Graham" wrote

Not necessarily. The picture I provided was an example of an intake plenum warping/leaking internally. It doesn't necessarily leak into the engine oil pan area either. That sector of the engine that is full of antifreeze does not have a path to the engine oil pan, but it can get sucked into the intake runners and then begin to burn in the cylinders.

Ian

Reply to
shiden_kai

"Bob" wrote

Bob, we are dealing with GM engineers here. I'd be loath to pronounce the problem permanently cured...but yes....the lower intake is actually the problem. Or rather, the EGR tube sticking up out of the lower intake is too large and has been redesigned with a smaller tube.

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Ian

Reply to
shiden_kai

"Mike Graham" wrote

Mike, I just replaced an intake manifold a couple days ago and the symptoms were identical to what you had described. When it got to the shop, it would not run until the plugs were changed. The coolant can foul the plugs so that it will not run. This problem is so common with these engines that a no start condition on a high miler usually means that we check coolant levels and leakage from the upper manifold. This customer also was losing coolant and adding it as he was driving from Sask to Calgary.

Ian

Reply to
shiden_kai

Assuming that the problem is identical, what kind of dollar figure is dear old dad looking at to get it fixed at the dealer? The warranty has expired.

Reply to
Mike Graham

"Mike Graham" wrote

I do like your thinking (assuming).

I believe that if only the upper is replaced, you will be looking at about 400 dollars for the part, and mayber 2.0 hrs labour.

If they insist on replacing the lower too.....then it will over 1000 dollars.

Anyone mechanically inclined in the family? It's not hard to replace.

Ian

Reply to
shiden_kai

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