Buick Lesabre Overheating And Hesitates

1997 Buick Lesabre Limited. I have had TONS of things replaced on this car, (approx $14,000.oo including purchase price and deer hit repair which is about $7,000 of that). Car has aprox 206K runs awesome, drives like new, everything functions. (or at least when i bought it they did).

The climate control display (digital) panel has been going out, and now is always black. This is one problem, related or not, also when i went to drive the car one afternoon, the battery was dead. I jumped it (properly) and drove to the store. When i got there, shut off car, i hear this noise, like a fan running. It was the heater fan, and it didn’t go out when i shut off the car, wiggled ignition, pulled key out, i had to shut off the heater via the controls. When i took it to mechanic, (and a good one, i know how to pick good ones, and this guy is fantastic, as opposed to some that are .. not so much) he spent 5 hrs, pulled off dash, traced wires, coded, and checked diagrams and finally found the problem. Ignition switch piece, and also when coding the Mass Airflow Sensor. Before he replaced that i had to drive the car a couple of days, and in doing so i noticed an overheating problem.

The car would overheat, (i know they run hot, and fans don’t kick in until about 227 degrees but the needle was on red before i shut it off and no fans etc.) it would not overheat while moving and keeping airflow, but it would overheat if idling. This was apparently caused by the little plastic ($5 part) on the intake manifold by alternator. (drawback was that it was about 5 hrs labor, ouch!) This was replaced.


Now the engine doesn’t overheat, or at least the needle doesn’t go above 200 (prior, i could let the car idle for hrs and the temp would hardly flux between 180 and 200, this thing’s a tank). I have taken this car all over the USA, from Michigan to Tenessee and various in between. Never misses a beat, never problems, perfect car in every mechanical way. So problem fixed, now when it gets hot, and i drive it slow like trolling a parking lot for a parking space, it will get hot, (excessive as in 15 minutes of idling around) not past 200deg but it smells hot, and the car starts to stutter and spit, and the idle drops to about 1rmp above stall. In fact it is so close to stalling that it would if i punched the gas.

Will not accelerate, the car shudders, makes small backfire noises, almost like a car starting off in high gear, or perhaps only running 3 of 6 cyls. When i put it in neutral or park, it sits there and does the same. when it cools off, the car stutters just like before and then quickly returns to normal, perfect running. Full power, everything. Intake manifold recall problem was fixed long ago, upper intake manifold replaced, little valve for coolant replaced, mas replaced, airways clear, coolant flowing, and car is always drippy, (it’s a Buick for god’s sake, that’s what they do right?)

I love this car, and even though i have replaced many things (mostly mechanical, hardly any electrical) this car as told by my mechanic, would get me from one coast to the other, in a blink of an eye. He said just check fluids and don’t fall asleep driving. This problem of overheating though has me worried, and i plan to take into mechanic, but i am also a best friend of a mechanic (for 10 yrs before i moved here) and i love trouble shooting car probs and understanding the concept of how stuff works. I have rebuilt engines, i have extensive mechanical experience, but this problem eludes me. I am sure my mech can figure it out, but damn, i am broke. Just trying to keep the replacement of needless things down to a minimum.

So what are the possible causes?

Answer: Possible low fuel pressure. Suggest checking when it is acting up. Under 200 degrees is not hot, so if you smell something, it may be because it is running lean- low fuel pressure. Also possible EGR valve stuck open a little because of a bad EGR valve, or carbon making it stick. Possible faulty ignition module. If you think almost like running on 3 cylinders, maybe it is. Need to verify spark, fuel pressure and injector pulse.

Car Problem Repaired

UPDATE: I was able to spend some time at the mechanib shop, and we plugged in the master scanner again, let the car run, (it has to run for a while to act up) and we observed 5 primary codes, MAP showing air backup, thus messing up vacuum systems (obviously affection running), also noticed a few others. When it was really acting up, it wasn’t trying to die, just no acceleration, and when it did accelerate it was choked.

Turns out the catalytic converter was gummed. Makes sense.

I will post further if that doesn’t end up the problem. Also, if anyone wants to know the rest of what i have done to this beaut’ of a land yacht just let me know. I can recall every repair and the symptoms easily. (and the prices).

Guess it’s time for a newer Buick Lesabre.

Thanks for your replies, this help site is bookmarked and super awesome!!