What is the popping noise in the back?
Buick lesabre, 100,000 miles 3.8 non-blown
Anyways, sometimes when driving or idling in the parking lot at work [to keep the heat going] I hear what sounds like something popping [like a ballon] from the back.
It is not super loud, and the car does not need to be driving to happen, it needs only for the engine to be running.
One other thing - it happens only when the gas tank is not full.
Now this may sound a stretch, but is it possible the fuel pump might be sparking or shorting out now and then and igniting the fumes in the gas tank? As we know, liquid gasoline will not readily burn... I don't know if such an ignition would be forceful enough to detonate the gas tank...
The car runs fine, there are no codes, it uses a normal amount of gas, and there don't seem to be any fumes. The cap seems fine. Only the occasional pop like a ballon.
I know this sounds REALLY stupid, but I would rather sound stupid than be BBQ.
1999 LeSabre, 3800 series II engine.