Huge win for car owners! All TSBs to be made public. The Center for Auto Safety just made the NHTSA (US Government) make public the full text of all TSBs from now on. They are the same organization that has petitioned the NHTSA & filed lawsuits to protect car owners over exploding gas tanks & other major safety issues. Whenever you drive in your car, you are safer thanks in part to a lot of work over the years by this small but very effective consumer advocacy group.

Please take a moment & say thank you by donating $5 or whatever you can to the Center for Auto Safety.

NHTSA — Engine And Engine Cooling Problems

1998 Pontiac Bonneville (Page 1 of 3)

10.0

really awful
Crashes / Fires:
0 / 0
Injuries / Deaths:
1 / 0
Average Mileage:
40,543 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

1998 Pontiac Bonneville engine problems

engine problem

Find something helpful? Spread the word.
Get notified about new defects, investigations, recalls & lawsuits for the 1998 Pontiac Bonneville:

Unsubscribe any time. We don't sell/share your email.

1998 Pontiac Bonneville Owner Comments (Page 1 of 3)

problem #45

Apr 032015

Bonneville

  • 105,673 miles

A D V E R T I S E M E N T S

The back two cradle mounts on both sides rusted out and mounts pulled through the cradle causing the steering to become loose filling and causing steering to be out of alignment and when hit brakes front would dart one way or the other and lots of noise coming from under vehicle from cradle bouncing when hitting bumps tried the find one in junk yards and all are that way.

- Centralia, IL, USA

problem #44

Jun 232011

Bonneville 6-cyl

  • 80,268 miles
The air intake gasket has failed for 2 reasons. 1 factory tightly put the bolts on to tight. 2 plastic gasket and plastic manifold parts do not meet government safety standards for, failure avoidance, because of materials used to connect the plastic to mettle creating a dangerous situation.

- Crown Point, IN, USA

problem #43

Aug 222010

Bonneville

  • 129,000 miles
My upper intake manifold leaks engine coolant into the combustion chambers and into the crankcase. The egr tube melts the upper plastic manifold I have had the upper and lower intake replaced for this issue once before with GM parts and it happening again. If it not fixed the coolant can contaminate my oil and lock up my engine when traveling down the road and possibly cause me to crash. If the engine locks up I will lose power steering and braking ability.

- Adrian, MI, USA

problem #42

Jan 012006

Bonneville 6-cyl

  • miles

A D V E R T I S E M E N T S

I own a 1998 Pontiac Bonneville SE. I saw recently that GM was recalling 1.5 million vehicles with the 3800 3.8 ltr V6. Was wondering how they could recall those vehicles and not mine, my car is in the same year range "1998" and has the exact motor "3800 3.8 V6" and oil drips on manifold on my car as well. What kind of info can I get on this? thank you

- Hazel Green, AL, USA

problem #41

Dec 272007

Bonneville

  • 78,540 miles
6 months after purchasing this professional cared for car (GM garage 8yrs) from my mother with only 62,000 miles on it I began seeing coolant on the engine which led me to have my mechanic at precision tune auto care take a look. He said it is likely a leak from either the plenum or the gasket. After digging into it they ended up replacing upper plenum and lower intake gasket and coolant and oil. Cost was $739.71. Mileage on car at that time was 78540. I have receipt from precision.

- New Brighton, MN, USA

problem #40

Aug 272004

Bonneville 6-cyl

  • miles
1998 Pontiac Bonneville poor production manifold/gaskets. Customer states that the manifold/gaskets and dex. Cool were in poor production on her vehicle. The upper intake manifold needed to be replaced. The thermostat and gasket had coolant in them. The mass air flow sensor was bad. Metal fragments were found in the oil which was coming from, the rod bearing that failed due to the vehicle over heating and coolant in the oil. The catalytic converter needed to be replaced because the vehicle was riding rough and the engine was shaking. The consumer stated there was a recall on the vehicle to prevent the manifold from cracking. After the recall was performed in July 2004, the manifold cracked one month later. The consumer stated ever since the recall was performed she has engine problems. The consumer stated when the upper intake manifold was replaced in August 2004 the lower manifold should have been replaced as well to prevent future damage, however since it was not replaced, stop leak pellets mixed with the dex-cool and the lower intake manifold leaked.

- Jackson, NJ, USA

problem #39

May 312006

Bonneville 6-cyl

  • Automatic transmission
  • miles

A D V E R T I S E M E N T S

: the contact stated, there was an intermittent problem starting the vehicle, a severe hesitation when accelerating from a stop, as well as backfiring of the engine. An independent service mechanic discovered low fluid levels in the radiator, wet and rusted spark plugs, cracked head gaskets and the piston had torn through the oil pan. The manufacturer the recalled (04V090000) item was replaced in July of 2004 by the previous owner of the vehicle and the recall was closed out. The vehicle was taken to the dealer service mechanic for computer diagnostics.

- Meridian, MS, USA

problem #38

Apr 112006

Bonneville 6-cyl

  • Automatic transmission
  • 127,000 miles
Disappearing coolant - no visible leaks. Engine quit running required tow. Replaced plastic intake manifold.

- Spring Hill, FL, USA

problem #37

Jul 102001

Bonneville

  • miles
1998 Pontiac Bonneville overheated. The consumer stated the engine started to sputter and then would pick up abruptly and then the engine light illuminated. The consumer was told water was coming out of the plug holes. The consumer had the vehicle towed to another establishment where he was then told the entire engine had to be rebuilt or replaced. The mechanic stated the manifold had a leak at the throttle body. The consumer stated the problem has resurfaced again 4 years later.

- Pensacola, FL, USA

problem #36

Nov 072005

Bonneville

  • miles
Please be sure to file your complaint at www.autosafety.org and sign up for the class action law suit against GMC. I know there are more people out there with the same engine coolant and plastic manifold problem that have had to replace or rebuild the engine in the 1998 Pontiac Bonneville.

- Pensacola, FL, USA

problem #35

Nov 072005

Bonneville

  • Automatic transmission
  • 60,000 miles

A D V E R T I S E M E N T S

There are 313 complaints on this website as of today concerning the 1998 Pontiac Bonneville. Out of those 313 reports, at least 132 are 100 percent related to the plastic manifold failure which causes the engine to overheat to catastrophic results. I have had to replace the engine on my vehicle twice within 4 years. GMC is refusing to acknowledge this issue and it is a shame that the almighty dollar is more important than integrity, honor and people's lives. What happened to pride in what you manufacture?shame on GMC!!!

- Pensacola, FL, USA

problem #34

Oct 012003

Bonneville

  • miles
Consumer disappointed with reimbursement for 1998 Pontiac Bonneville. The fuel pressure regulator was replaced. Recall campaign: 04V090000. The recall is related to the fuel pressure regulator leak. The temperature gauge was fluctuating while the vehicle was being driven. The check engine light did not come on. The consumer turned the engine off and allowed it to cool off. The consumer restarted the vehicle and heard a loud back fire with a loud bang. The vehicle did not restart. The consumer smelled fuel shortly after. The vehicle was towed to a nearby dealer. The intake plenum and the intake plenum gasket needed to be replaced. The thermostat blew out again. The consumer stated that he feels that the failures are a result of the recall issue therefore the reimbursement check was not sufficient. The consumer stated that the brakes had a ticking noise.

- Evans, CO, USA

problem #33

Oct 022004

Bonneville

  • miles
1998-Bonneville 70,000 miles. Started stalling intermittently on one occasion, got car to mechanic and found out that the upper plenum had a hole burned right through it. Had to replace the upper manifold because of coolant leaking into the engine. $910 later it is fixed. Did some research and found that GM is aware of this problem and know of numerous complaints about this. Wondering when they are going to call for a recall"????"

- Kimberly, WI, USA

problem #32

Aug 082004

Bonneville

  • Automatic transmission
  • 58,183 miles
No events lead up to the failure, it was immediate. Car stopped dead in its tracks, started one more time before it died in 1/8th of a mile. I was informed that the intake manifold was the problem coolant leaked into the engine. Replaced intake manifold, gasket, oil filter, oil, coolant & spark plugs.cleaned out coolant from intake and cylinders. Change oil and filter.

- Savannah, GA, USA

problem #31

Dec 042003

Bonneville

  • Automatic transmission
  • 86,000 miles
When driving the vehicle at an undetermined speed, the vehicle stalled causing the driver to drift off the road. The consumer had the vehicle towed to the dealer for inspection. The mechanic informed the owner that the intake manifold had failed.

- Wapakoneta, OH, USA

problem #30

May 202004

(reported on)

Bonneville 6-cyl

  • Automatic transmission
  • miles
Consumer had the same problem as mentioned in NHTSA recall 04V09000: Vehicles equipped with 3800 V6 (L36) engines and certain delphi fuel pressure regulators, the regulators have a much higher than usual rate of fuel leaks. A leak can allow fuel to enter the intake manifold through a vacuum line. Dealership admitted this vehicle has the same problem, but due to VIN# wont fixed free.

- New Lenox, IL, USA

problem #29

Apr 302004

Bonneville 6-cyl

  • Automatic transmission
  • 115,000 miles
Purchased used 1998 Pontiac Bonneville in January, 2002 with 56, 000 miles from GM dealership. Car was GM certified. About 6 months later with 65,000 miles during routine oil change I notice the coolant was a little low. Going back to dealer I purchased GM long life antifreeze and bottle of GM sealant. There were no visible signs of antifreeze leak anywhere. Coolant level maintained from that time. On April 30th, 2004 while driving down the expressway, the car suddenly begain to miss fire severley and quit running within seconds. There was no power steering and no power breaks. The engine had hydrolocked. All cylinders were full of antifreeze. The car now had 115,000 miles. I removed the upper intake manifold to find it full of antifreeze. The heat resistant material around the egr tube had failed allowing super-heated air to melt the gasket area around the adjascent water jacket allowing coolant to flow into the manifold causing the hydrolock. I replaced both upper and lower intake manifolds and gaskets with newly designed units from the dealer. I was told GM was aware of the defect and had redesigned the parts against this failure. The car is now running fine. While there was no accident involved, the sudden power failure certainly could have caused an accident. I believe the failure began at 65,000 miles and was temporarily fixed with the coolant sealant I put in it at that time as recommended by the dealer's parts person. All parts are available for inspection.

- Burt, MI, USA

problem #28

Dec 152002

Bonneville

  • Automatic transmission
  • 0 miles
Engine intake manifold and gasket failed while car was being driven in rush hour traffic, on a major highway, with traffic moving at a speed of apx 70 mph. This manifold and gasket failure resulted in the engine stalling, further causing a loss of steering and braking control. Several cars swerved and skidded to avoid collision with our disabled car. The car was towed to the selling Pontiac dealer. The intake manifold and gasket had failed, and the cost of repair was $1,036. I have found out that the intake manifold and gasket had been improperly designed, and that a high failure rate is occurring on GM V-6 3.8 engines. I contacted GM, and they will not help with this. There are many web sites that verify thousands of other failures. Also, a GM service manager that I spoke with at a different dealership has acknowledged that there is a problem, and that many times, the engines fail due to this problem, resulting in a $5,000 replacement of the entire engine. This problem needs to be addressed, as GM is laughing at the public on this one. Who of us has the resources to challenge them, and they could care less if we ever buy another car from them.

- Woodbury, MN, USA

problem #27

Dec 152002

Bonneville

  • Automatic transmission
  • 0 miles
Leaking plastic manifold has hydrolocked my engine and bent 5 pushrods. Also the dexcool antifreeze entered the cylinders and oilpan, ruining the engine.

- Raleigh, NC, USA

problem #26

Dec 152002

Bonneville

  • Automatic transmission
  • 0 miles
My complaint is that I am about to put my 4th and 5th intake manifold & manifold gasket, respectively, on my 1998 Pontiac Bonneville. I was driving down highway 55 at 70 mph when my engine died, because my manifold keeps cracking!! because my engine died, it kept blowing and forcing antifreeze down my intake and filling my cylinders with water and antifreeze, causing a vapor lock!!! this was terrible, because when I tried to restart the car in neutral going 70 mph, with 20-25 cars around me and 3-5 semi trucks, the engine was locked up!!!!! because of this 'vapor lock up' of the engine, I lost control of my car!!! I had no power steering, no power brakes, no control to be able to avoid a 20-25 car pile up, with tens to hundreds being injured!!!!!!!!! GM needs to do a complete recall of all 3.1, 3.4 & 3.8 V6 engines made with plastic manifolds and plastic gaskets!!!! GM needs to replace them with the aluminum manifolds and rubber gaskets they used to place on all engines manufactured since these changes which I believe is 1996!!!!! next, after all these manifolds and gasket failures on my car, of which I change the oil every 2000 miles and have documentation to support my oil changes, the antifreeze has eaten my bearings and crankshaft mains and rod bearings and my engine is knocking badly!!! a fair resolution would be for GM to give me(free of any charge), a new engine to replace the one they damaged, with their defective parts, workmanship and manufacturing design changes. If there is no problem, then why has GM issued a very expensive tsb" to change the design, component and installation of these defective parts??????? please see the attached url -www.petitiononline.com/mod_perl/signed.cgi"gmcnsmrs to view the over 1,200 people so far that has been identified in just a few months by word of mouth. Thank you, gregory D. douglas 280 wildridge road metamora, il. 61548 home (309) 822-0406 work (217) 557-0313

- Metamora, IL, USA

Read the next 20 complaints »

Not what you are looking for?