Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1997 Pontiac Bonneville owners, lightly cleaned up (personal details are redacted by NHTSA).
Car completely shuts down while decelerating at anywhere from 30-55 MPH. Sometimes can restart, sometimes not for a half hour or so. The car's engine coolant has leaked out onto engine. Car shut down, no power, no steering, no brakes, then the coolant spilled out everywhere, engine started smoking and now the engine has stopped working even after replacing head gasket. Car had been into dealers numerous times to no avail. No one could identify the problem. Now have a car that had to be towed and is no longer functioning. Numerous fuel injectors were replaced in hopes of stopping the stalling out and shutdowns, but nothing has worked. Waiting for a couple of quotes on what it will take to try and fix the engine or most likely need replaced. This has been happening since the car was fairly new.
I had a 1997 Pontiac Bonneville. While I was driving down a highway in michigan, the engine compartment suddenly caught on fire. I was not speeding, and my car was perfectly serviced and maintained. By the time the fire service got there, the whole car burnt down. It took less than 20 minutes for the whole car to get burnt beyond recognition.
The car lost all power while driving on several occasions. It would just quit and I would have no brakes or steering and all gauges would shut down. Sometimes it would lose power and then it would come back on while I was still driving cutting in and out repeatedly. It happened a lot when I was idling at a corner and then would start through the intersection. It would quit going through the intersection. Sometimes it wouldn't start after driving it a short distance. After it sat for a few minutes, a few hours or sometimes overnight it would just start like there wasn't any problem with it. It didn't sputter or act like it wasn't getting gas or anything, it just wouldn't do anything and had a total loss of all power. We took it in for repair several times and they could never replicate the problem and diagnostics didn't show any problems that would cause this issue. …
The intake manifold or the plemium whatever you want to call the thing wore out and all of my engine coolant went into the fuel cylinders and locked my motor down I was headed to macon ga from douglas,ga going to the hospital were they had transfered my brother and here I am in perry,ga broke down because Pontiac puts a plastic intake manifold on a motor I feel like Pontiac should have to pay for this part being replaced. I also have trouble with my car surging between 35 and 55 miles per hour this is the sorriest car I have ever owed and I have owned 2 grand prixs before this car but liked the body style of the Bonneville and I rhought that it would be a good car but boy was I wrong I bought the car in August,2002 and have spent enough money on repairs on it that I could probably done paid for another grand prix.after reading all the complaints on this sight I feel they should have a …
My car wouldn't start and there were no electrical components functioning. I called the car dealership where I purchased the warranty and was told to make sure I didn't have a dead battery because that was not covered under the warranty. I called the towing company and they attempted to charge the battery. Battery would not charge; the car went "puff" and caught on fire. When the wrecker driver attempte to start the car, he heard a loud "pop" and smoke was rolling out from under the hood. He opened the hood, battery was intact, however the engine was on fire. After fire was extinquished, he found the plenum(?sp) blown off the top f the engine and the oil filtler tube was blown out of he top of te manifold. Warranty company would not cover due to the fact the car caught on fire. They said my car ins should cover it. …
G.m. 3800 seriesii v-6 engine plastic upper intake manifold plenum & gaskets. Failure of inferior parts in conjuction with dex cool (g.m. Anti-freeze/coolant). Causing deterioration and failure of plenum forcing coolant into engine. Engine immediately seizes,trying to restart will cause damage to starter,flywheel,batt.,and engine. Remedy? Tow to g.m. Service center replace upper intake manifold plenum,manifold gskts,spark plugs & wires,starter,pwr-flush eng.& cooling sys.,replace all fluids. G.m. Is aware of problem they should be held accountable. Service mngr. Told me damages to veh.was not due lack of maintenance but use of plastic parts and coolant by g.m. This a major defect & problem. Cost of repairs? $1,300.00.
The intake manifold gasket on my 1997 Pontiac Bonneville 3800 series engine failed causing coolant to gain access to internal engine parts. This caused the engine to seize and become totally inoperable requiring the engine to be replaced at a cost of $2200.00. This failure also happend in a Pontiac grand prix, that I also owned, with the same series of engine. The cost of the repair to the grand prix was approx. $650.00. The engine in the grand prix did not have to be replaced. Looking at and reading the various GM message boards on the internet, this problem seems to be fairly prevalent with the 3800 series of engine. GM continues to ignore this with no regard to the consumer.
While driving a 100 miles from home the car overheated & had to be towed. We found that the problem was due to a hole in the air plenum in the upper intake manifold. We have found that there are over 20 such cases in our small community alone. All on 3800 motors in Pontiac's. This is a four hundred dollar repair bill that occurred only because Pontiac decided to use plastic in their part which in turn melted & caused our motor to overheat. I hope that Pontiac will recall these plenums & reimburse us for the cost of repairing & towing our car. If Pontiac would call their dealers they would find out just how many of these parts have malfunctioned.
Tl contact owns a 1997 Pontiac Bonneville. The vehicle was leaking radiator fluid. The dealer repaired the leak. A year after the repair, the fan connected to the heater and air conditioner stopped working. There was a popping noise intermittently under the hood near the defrost and suddenly, the front window cracked. The dealer has not diagnosed the failure; however, a manufacturers defect does exist. The heater fan also failed to operate intermittently. The failure mileage was 83,000 and the current mileage was 93,000. Updated 11/10/09 updated 11/13/09.
The plastic intake manifold on my 1997 Bonneville warped causing coolant to leak into the engine which then seized the engine. Replaced intake manifold and rebuilt both engine heads. Total cost was $1,525. My mechanic told me this is a common problem on the GM 3800 series engines because the upper intake manifold is plastic. About 2 weeks later, a rod bearing failed. I was told it failed prematurely because coolant had entered the engine. I do not have a repair estimate yet. I believe all of these problems are related to the defective upper intake manifold.
NHTSA investigations
Engine compartment fires
Engine complaints in other Bonneville years
Frequently asked questions
How common are engine problems on the 1997 Pontiac Bonneville?
NHTSA has 51 complaints about the engine & cooling of the 1997 Pontiac Bonneville, 35% of the model year's 147 complaints. The component named most often is engine › gasoline (24 mentions).
Is there a recall for 1997 Pontiac Bonneville engine problems?
No. NHTSA lists no engine & cooling recall for the 1997 Pontiac Bonneville, though it has 1 recall for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1997 Pontiac Bonneville engine problems start?
Half of the complaints with a recorded mileage happened before about 100,000 miles.
Is it dangerous?
Owners linked 0 crashes, 10 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.