QuestionI have a 1996 BMW 318ti with ~90,000 miles on it. It has been serviced regularly and runs fine. However, about 9 months ago I noticed a strong smell of gas inside the car after it sits overnight in the garage. After a couple of minutes with the windows open the smell dissipates and doesn't return until the next morning. It has been to a local BMW shop twice in the last 3 months but they were unable to locate the source of the smell.
The only modifications I've done to the engine are replacing the standard air filter element with a K&N filter element, bypassing the standard airflow input to the air filter box with a 3" flex tube that extends down below the left foglight, and replacing the stock exhaust system with a SuperSprint exhaust system.
The only thing I have noticed that changes the strength of the smell is the speed at which I drive home. If I drive at 80mph or above the smell is almost non-existent. If I drive at 70 it is very strong. Strange.
Thanks for what ever help you can provide.
Mike Z.
AnswerWhen you walk out to your car in the morning, does it smell like gas with the doors closed? if so, the problem is most likely in the engine bay.
I don't know if the 318's had the access to the gas tank under the back seat but if it is, take it off and replace the seal.
have the mechanic do a gastank pressure test. if all else fails, you might consider takeing the car somewhere that has a devece that sniffs the air to tell you parts per million of a substance.
-cheers
