10.0
really awful- Crashes / Fires:
- 1 / 1
- Injuries / Deaths:
- 0 / 0
- Average Mileage:
- 32,036 miles
About These NHTSA Complaints:
The NHTSA is the US gov't agency tasked with vehicle safety. Complaints can be spread across multiple & redundant categories, & are not organized by problem. See the Back button — blue bar at the very top of the page — to explore more.
I am the owner of a 1998 Pontiac Bonneville with a 3800 engine. I am the original owner and the car has less then 42,000 miles on it. The upper intake (plenum) and seals have failed resulting in coolant leaking into the engine. I phoned an acquaintance who worked as a technician at the GM power train engineering facility in flint, Michigan where the 3800 engine was engineered. He said it was common knowledge by the engineering skilled trades employees that the upper intake design was flawed. There were many intake failures observed during dynamometer testing. Some even exploded. I was told that the engineers and management was well aware of the defective design, but for some reason, changes were not made. I can direct investigators to employees who witnessed intake design failures in the testing facilities.
- Flushing, MI, USA
Driving on highway when 1998 Pontiac Bonneville with low mileage had service engine alert go off. Car gauges indicated it was over heating. Pulled off road to check out and found antifreeze low-never saw any leak or puddle. Cooled car and added antifreeze. Car worsened and acted like it was going to start fire. Huge white smoke out of tailpipe & loud engine noise. Towed to repair shop where they said it is intake manifold design defect due to plastic casing on many GM models. They replace at least one per week. Stranded out of town for over 8 hours. Oil and antifreeze in all sparl plugs. Spent $1100 to have new "updated design manifold", oil changed twice, coolant flushed, new spark plugs and new starter done due to a chunk broken off of cone because of manifold rupture.
- Essexville, MI, USA
Consumer started the vehicle, went into the house to let the vehicle warm, upon returning the vehicle was on fire. Recently a recall 04V090000 was received indicating a possible fire.
- Florence, SC, USA
Engine had 70,000 miles when suddenly seized with no warning. Repair said intake manifold had warped causing antifreeze to spill into engine. Engine and starter had to be replaced. Repair center said it is a very common problem. Replacement engine had same thing happening and a kit is available for replacement of this problem-purchased kit for replacement engine. Total replacement costs---$3,223.06. I see in browsing the complaint pages that this is a very common problem. Its time that GM makes things right for the consumer.
- Fowlerville, MI, USA
Catastrophic engine failure while traveling on a bridge at apprx 15 - 20 mph. No warnings lights or gauge concerns until moment of failure. Engine idle became exceptionally rough. Cause was a gasket failure allowing dex-cool to enter engine and destroyed it.
- St. Augustine, FL, USA
1998 Pontiac Bonneville plenum warped and leaked anti-freeze into combustion cylinders. Vehicle was not able to be started and had to be towed to dealer. Resulted in over $900 charges of which $317.64 was not covered by extended warranty.
- Farmingville, NY, USA
Possible defective engine part. Pontiac 3.8L intake manifold failure causing possible catastrophic engine failure if engine vapor locks at time of failure while engine is running. This part failed on my vehicle and the independant repair shop I took it too already had needed repair part on hand because (as they stated) there always fixing this engine for this problem. I found 1 tsb on your site #01060007A but it was 2.5 years ago. I spoke with a GM representative but was advised the could not comment on if this was a problem or not.
- Summerfield , FL, USA
Engine stopped on interstate. Car was towed. Failure analysis indicates intake manifold failed allowing engine coolant to be drawing into engine causing hydrolock. Car had about 60,000 miles. Have found numerous other owners of other GM cars with 3.8L V-6 engines with same problem.
- Miami, FL, USA
Consumer bought the Bonneville in August, since then it has been in repair shop 7 times. The first four times were for transmission failure. They replaced the pressure control valve and throttle body. The remaining visits were for 4 fuel injection system failures, injector coil failures melted 4 spark plug wires. Also, water pump started leaking.
- Elwood, IN, USA
Consumer called complaining about antifreeze leaking into the intake manifold. Manufacturer and dealer were contacted, and stated that there was a recall on a different vehicles with the same engine but not on this particular one.
- Statts Mills, WV, USA
Coolant was sucked into the cylinders through two unknown holes in the intake manifold system. Engine had 66,000 miles. Resulted in total blow-out of engine and replacement was necessary at a repair cost of close to $3,000. According to service technician this engine has a history of these problems and GM needs to rectify the faulty plastic manifolds and gaskets.
- Independence, MO, USA
While traveling on the highway and without prior warning coolant was leaking into the engine, causing vehicle to overheat.
- Longview, WA, USA
Plenum part number 17113136 failed have incurred $511.78 in damages through GM's neglect to admit to a design problem and their failure to do a voluntary recall, car still does not run properly and will end up costing more money to correct.
- Ambridge, PA, USA
The antifreeze leaked and caused damage to the rod bearings, and crankshaft.
- Metamora, IL, USA
Upper intake crack which caused coolant leak into intake and fuel system.
- Oak Ridge, TN, USA
While driving vehicle stalled out. Had vehicle towed. This was a result of coolant fuel leaking.dealer contacted.
- Lakin, KS, USA
Consumers vehicle experienced an engine coolant leak.
- Turtle Lake, WI, USA
Engine would not run due to coolant in cylinder/S, cost to replace plastic intake manifold apx. $900 the term degrade as used by GM should be defective as by all experience, an intake manifold has no moving parts to wear and the car was equipped with coolant which does not need replacingg until 150,000 miles or five years. There is no maintenace that any owner can do to prevent this from happening. If it happens when in traffic and the engine stopped, there will be serious safety problem. GM does not want to take responsibility for a defect or design problem.
- New Bern,, NC, USA
On 8/25/2000 had to have my water pump replaced($536.91). Picked up car went 11 mile it quit had to be towed back to performance Pontiac. Informed at that time the plenum failed cost of that job including towing an rental ($830.80). On 3/20/2002 car quit had to be towed in to performance Pontiac again. Cause of the problem the plenum failed again. When I called GM Pontiac division they said there is nothing that they can do because of the mileage of the car. I do not believe that is the issue. It's a $31000. I travel for a living and have the upmost respect for my vehicle. I have all my records of my maintenance that would amaze you. The car has never been over 3000 before each oil chg. Tires are rotated every 5000 miles. Transmission oil chgs has been done twice. Brakes have been repaired twice prematurely to prevent serious damage to other parts. I can provide you with records that show to the penny what I've spent on gasoline from the day I bought the car. I am convined that it is not a mileage issue and totally convinced that this is not a result of any negligence on my part. I was totally turned off by the attitude of Pontiac concerning the problem with this part. I can also provide you with testimonials from businesses that I use to service my vehicle to what a fanactic I am about preventitve maintenance. Waiting anxiousley for your reply. Thank you for listening. Nick leogrande.
- Syracuse, NY, USA
- Laporte, In 46350, IN, USA