1999 Oldsmobile Sillouette. Please help.

GENA79

MEMBER
1999 OLDSMOBILE SILHOUETTE

Popping noise coming from engine area when you let off the gas. Can only hear it when hood is up. Sputters very lightly at red lights, drive thru. (Acts like it wants to die but not quite at that point) At muffler shop getting the catalytic checked, watched when he let off the gas. Popping noise, then a second later small puffs of white smoke puffed out. Exhaust is puffing. NEver steady rate. Seems to have quick pauses in escape. Does not smell sweet to me. Mechanic looked at it, but couldnt say for sure what it is. Told me I could have the start of a blown head gasket. Did throw out a code last week. Catalyst effieciency low bank one. Catalytic tested fine. No noises when manipulated and the test came out fine. Please help. Im a single mother and cant afford a new car or paying a different shop every other day.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

The white smoke sounds like the start of a headgasket issue or an intake gasket leak. If you have the 3.1L V6, the intake gaskets are most common. However, the noise you hear, "only when you let off the gas, " has me confused. A slight exhaust leak will make a sound when you hit the gas (exhaust manifold)and it could make a popping sound when you release. Without being there, it is hard to be sure. What I want you to do is go to a different "exhaust system shop" and tell them you were told that the sound is from the exhaust manifold. Ask if they could take two seconds and listen to it. Many times when they think you know what you are talking about, they will go directly to the problem and not try to find everything wrong with the car. Please also keep in mind, a slight puff of steam (white smoke) from the exhaust isn't too odd when the engine is reved in neutral. If it is consistant, then I would have a concern. Monitor your coolant to make sure it isn't going low on you. If it isn't, then chances are there are no leaks.