Design flaw of coolant pipe. Breakage of the coolant pipe inside the air intake of the 3800 V-6 engine causing engine coolant to flood the engine and cause immediate engine failure.

- Wilmington, NC, USA

While driving 30 mph engine service light flashed. Then, engine stalled. Consumer was informed by dealer that engine needed to be replaced.

- Fowlerville, MI, USA

Repeated stalling in traffic. Typically occurred approximately two minutes after start-up. During one cold start the engine miss-fired and back pressure popped off the brake vacuum line, causing loss of brakes. Was diagnosed first time as mass air flow sensor. Problem recurred, diagnosed as fuel pressure regulator. Shortly after, flooding and sparkplug fouling occurred due to damaged intake manifold leaking coolant into cylinders. While two of the components are the same as recall campaign 04V090000, and GM recall 03054B, GM says this VIN [xxx] is not included. Updated 07/30/2012 information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6)

- Hoffman Estates, IL, USA

Engine is idling and running rough due to anti-freeze getting into the cylinder. This could locked up the engine. The consumer it was a common known issue with the engine manifold which was made of plastic and warped which allowed coolant to leak into the cylinder.

- Byron Center, MI, USA

The upper engine cover and plenum broke. The fuel pressure regulator leaked onto the intake and caused a backfire. The pressure regulator was replaced, and the lower and upper intake was resealed. The vehicle was restarted but stalled. (the loud noise was heard at start up)

- Muskegon, MI, USA

Dexcool coolant corroded an upper plenum intake costing me $1,1185. This Pontiac Bonneville only has 69000 miles on it. My mechanic says GMC is aware of the problem and is doing nothing about it.

- Olthe, KS, USA

On November 4, 2003 my wife contacted me at lunch time to inform me her car would not start. After checking the battery and starter it was determined the motor had locked up. When I contacted the dealer I found that I still had 1 year left on my extended warranty although at 88,000 miles I was 500 miles over the extended warranty. They informed me this was classic signs of the air intake manifold. I proceeded to repair the car myself. After taking the air plenium off the air intake manifold I found the top of the air intake manifold filled with anti-freeze. Apparently, the air plenium had developed a crack and allowed the anti-freeze into the air intake. This permitted anti-freeze to fill number 1 cylinder with anti-freeze and would not allow the piston to travel to the top of the cylinder. After searching the internet it became apparent I was very lucky. There were several cases reported on line where this happened while people were driving and caused major lower engine repair such as shattered rods and crankshafts. I also noticed there appears to be a large number of complaints on your web site on this issue. I sent an email to General Motors via their web site on this issue. It amazes me that this part is made of a plastic composite material and is mounted to the top of the engine. With the heating and cooling cycles the engine goes through, it is only a matter of time before this product would fail. From what I have seen on the internet and talking to various part clerks it is between 80,000 miles and 100,000 miles when this product fails. I am not sure if this is designed intent by GM, although they have not changed this design through the 2003 models. Needless to say I did not get a response back for GM. I felt with this type of defect and the safety problem this could cause if this were to have happened while traveling down a major highway there should have been a recall on this. Sincerely, william J. fitzgerald.

- Raleigh, NC, USA

1998 Pontiac Bonneville, 3.8 liter V6, 65K miles when its intake manifold "plastic" gasket warped under normal use. Coolant damaged it when drained into engine. GM has several service bulletins out there regarding their 3.8-liter V6 and this problem. They know it's defective in their design, but refused to cover any percentage of repair cost. Luckily, the car was not traveling down the interstate and no one got hurt from a locked up or destroyed engine. GM should recall or offer a repair copy on their defective design. Service bulletin replaces "plastic" part with redesigned aluminum one. They know its a problem, it's time they make it right.

- Warner Robins, GA, USA

On September 19,2003, my 1998 Pontiac Bonneville with 3800 V6 overheated(check engine light and high temp on gauges), would not restart and would not turn over by starter motor. Had to tow into shop and had cooling system checked. Pressure leaks were detected. The shop mechanic diagnosed that the upper plenum for the intake manifold, which is made of plastic, had become warped where the egr valve connects to the engine block. This allowed antifreeze to fill up the engine cylinders. The small repair shop where my car was repaired stated that they had replaced many of this particular upper intake plenum for this particular engine. The tow truck driver told me what the problem was even before I told him the entire problem.

- Lincolnwood, IL, USA

This car has had very good care/maintenance, has not been driven hard, and has only 67,000 miles on it. While driving down a city street, approximately 35 mph, the car began to sputter. I pulled in to a parking lot and shut the car off so that I could look at the spark plug wires. I had a spark plug wire loose when this happened once before. I had no over temp, I had normal oil pressure and there was no check engine light illuminated. I did not find a noticeable problem, but I could not get the engine to start again. I had it towed home. I changed the battery, the starter, and finally checked to see if the crankshaft would turn, which it wouldn't. I removed the spark plugs and tried it again. I got antifreeze from four of the cylinders! this was determined to be because of a failed intake manifold gasket.

- Blackfoot, ID, USA

Consumer called complaining about having gasket problems. Gaskets have been replaced twice, and he was concerned. Manufacturer was not contated at the time of this call.

- Folsom, CA, USA

The intake manifold is made of plastic and because it is cooled by the engine coolant it regularly fails.

- Loudon, TN, USA

While driving at 35mph and without warning the engine blewout, causing the consumer to pullover. Dealer notified.

- Aurora, OH, USA

My 1998 Bonneville had been loosing antifreeze, the dealer replaced the thermistat, then the water pump went out. It still lost antifreeze....a couple weeks later while driving down the road it just died in the middle of the road. My intake manfold aloud my engine to fill with antifreeze, GM has a kit for this problem.....so they know it is a problem.

- Haysville, KS, USA

The consumer was driving 20 mph around a corner. When the consumer attempted to accelerate the vehicle began to buck, the check engine light illuminated and the car suddenly stalled. The dealer diagnosed that the upper intake manifold gasket failed. The plenum failed and caused coolant to enter the engine. The engine hydro-locked due to a faulty gasket that GM had known about. The engine, starter and plenum was replaced.

- Turners Falls, MA, USA

The vehicle stalled without warning. The dealer stated oil mixed with the anti-freeze.

- Versailles, OH, USA

Engine lost coolant - informed by dealer that intake manifold had warped allowing coolant to mix with fuel and air. Dealer said that this part was a plastic composite part that failed often. Failure could cause engine loss or fire. Intake manifolds are not supposed to warp under normal conditions. **dimsii IVOQ entry posted after 12/12/02 cut over to artemis**765826

- Valparaiso, IN, USA

Bonneville engine over heating and upper manifold cracked and broke.

- Hallandale, FL, USA

Coolant was sucked into the cylinders through a hole in the plenum which is part of the intake manifold system. I have read over 40 complaints detailing the same problem at this location. This engine had only 56,000 miles and dealer refused to warranty or to assist with costs. This is clearly a wide ranging defect and this fluid lock can suddenly and unexpectedly stop the engine while in traffic causing a potential for serious accidents. This defect affects all General Motors vehicles with the 3.8 L engine yet General Motors has refused to do a recall and I cannot detect any action by NHTSA to investigate this and force a recall. It is time to do this.

- Williams, AZ, USA

While vehicle was parked, the engine caught on fire. Dealer has been notified.

- Tremont, IL, USA