- the contact stated that she brought he 1999 Oldsmobile Silhouette to dealer in costa mesa, ca for an oil change. The dealer stated that the plug booths melted, and that the spark plugs, and plug wires melted as well, and the head gasket failing. The contact stated that this is a safety hazard since she never got any prior warning about the failures on her vehicle.

- Huntington Beach, CA, USA

Leak in the defective intake manifold gasket, which has been diretly related to engine failure, which I now have with my 1999 olds silouette - cost to replace engine - $4,500 - having collant leak into the oil can not be good for any engine! GM will not own problem

- Oneonta, NY, USA

Intake manifold gasket leaking on 1999 Oldsmobile Silhouette with 64,000 miles. $900 repair. Apparently this is a common problem that GM will not accept any responsibility for a design defect.

- Jacksonville, FL, USA

At 35,000 my '99 olds burns 2 quarts of oil every 1000 miles! I just purchased the vehicle with a 60 day 100% engine and drive train coverage so the dealer is going to "fix" the problem. I have heard the GM 3.4 L engine is famous for poor pistons in all years. This engine is already shot at 35K miles and I feel can't possibly be repaired adequately...it should be replaced but the dealer won't do it.

- Kasson, MN, USA

I own a 1999 Oldsmobile Silhouette with 64,000 miles. I took the van to a local dealer because of a knocking noise on cold startup. The dealer diagnosed the problem as a failed intake manifold gasket. The failed gasket ruined the hydraulic lifters and had to be replaced. The total bill was $1500. The van had regular maintenance (oil, filters, anitfreeze checked) every 3000 miles. This seems to be a common problem with GM vehicles and dexcool systems. This could have been a major safety issue had the engine failed while driving.

- Plainfiled, IN, USA

Lower intake manifold gasket failure. This problem has also occured to a friend of mine who owns a 1999 olds Silhouette.

- Town And Country, MO, USA

Intake manifold gasket failed allowing dexcool coolant into the engine and mix with the oil. Total engine failure. Manifold gasket replaced at 58,000 miles. Engine rebuilt at 62,000 miles. Apparently this is happening on thousands of GM vehicles and GM will not cover the cost. In no way should a 1999 van need a new engine.

- Mason, OH, USA

Car went to dealer to diagnose a knocking sound on cold startup. Diagnosed as a failed intake manifold gasket, cost to repair approx $900. On disassembly, dealer contacted me and stated that the engine internals were so badly fouled (sludge and deposits) that hydraulic lifters needed replacement, cost approx $450. I asked how this could have happened, van has always had engine oil changed at 3000 mile intervals, with new filter and correct oil, and I don't know what to do differently to avoid this happening again. No advice offered, and no suggestions for why the gasket had failed.

- Woodinville, WA, USA

Coolant level low light came on. Took it in for servicing and oil change. Tech said the intake gasket was leaking and that the radiator was full of mud. Took it to a GM dealer the next day and found the gaskets were leaking and that it would require at least 1 radiator flush, possibly 2.

- Columbus, MS, USA

Leaking intake manifold gasket cause oil to be contaminated with coolant. Engine failed.

- Somerville, NJ, USA

Known problem with GM engine V6 3800, leaking antifreeze into engine. Intake manifold gasket failure.

- Naperville, IL, USA

I own a 1999 Oldsmobile Silhouette with 52,000 miles. I brought it to the local dealer because of a knocking noise on cold startup. Diagnosed as a failed intake manifold gasket, cost to repair approx $900. On disassembly, dealer contacted me with information that the engine internals were so badly fouled (sludge and deposits) that the hydraulic lifters required replacement. I asked what could have caused this situation, since the van has always gotten regular oil changes every 3000 miles, with new filter and correct oil, and I don't know what to do differently to avoid this same problem again. No information or advice was offered on why the gasket failed, or why the engine was so badly fouled.

- Woodinville, WA, USA

I have had this vehicle since 3/99. In which time I have had to bring it back for transmission problems, electrical problems, leaking fuel injectors, brakes, non working cruise control which led to the dealer replacing the compressor. Front end leaked anti freeze which led to another major job. I am not a happy motorist here. The steering column squeeked. They greased it. Turned out there was a problem with the rackinpinion. I know something about cars and I know that for the amount I pay for this vehicle, I shouldn't be having these major problems. Bandade fixes don't cut it with me. Nlm

- Lakeland, FL, USA

Consumer states that the head gaskets are leaking coolant onto the engine. The dealer has inspected the vehicle. The part is on national back order. Nlm

- Harrisburg, PA, USA