Replaced plenum on 1996 Pontiac Bonneville three times. Last time was approximately at 87,000 miles. Faulty (plastic) part allowed antifreeze and oil to mix in the engine causing stalling (in the middle of a busy state road intersection, a safety hazard). The mixing of the fluids allows the engine to burn the antifreeze and by the time you realize anything you are overheated. This was the third time I had the same problem.

- Congers, NY, USA

My 1996 Bonneville was towed to a repair facility on Monday morning, Sept. 22, 2003. I was informed that my engine had gone into hydraulic lock. The plastic intake had cracked and filled the cylinders with coolant. I had to have the head removed and surfaced, the head gasket replaced and several other related items. The repairs totaled to over $2000. This was very frustrating because I am very careful to have all of my maintenace done on time and all of the fluids changed every 30,000 miles. If you can help with this, it will be most appreciated. I have discovered that there is a continuing problem with this design of intake.

- Gastonia, NC, USA

Failure of intake manifold and gasket on my automobile. Allowed engine coolant to leak into the cylinders of the engine. Car: 1996 Pontiac Bonneville with 3.8L V-6 engine, using the dex-cool GM coolant. Repairs required a complete replacement of intake manifold and all engine gaskets. Repairs costs exceed $1400.

- Pittsford, NY, USA

11/01/2002 I had my car serviced. The mechanic told me that the manifold had coolant on it. 11//02//2002 I went to the part department at the Pontiac dealer and asked if there had been any notices about the intake manifold. They told me on 11/05/2002 the car would not start. Finally I got it started and had white smoke filling the area. I got it to the mechanic because I was not sure what had happened and also because Pontiac had said they had no information on the manifold. 11/07/2002 I picked up the car with the replaced manifold. They also gave me a copy of bulletin no. 01-06-01-007 dated Feb. 2001. The bulleting identifies the problem and the redesigned parts that are the replacements. It is a design problem in many engines in many cars that are listed in the bulletin. The mechanic said I was lucky I did not lose the engine. It seems Pontiac has identified the problem, has designed a solution but will not acknowledge they created the problem and do a voluntary recall. Your help is appreciated.

- Provo, UT, USA