OT--Weird Booming from Lumina

[JerseyHarold]

One morning a while back I started my '98 Lumina and I heard/felt a 'booming' come from under the car. It boomed twice or three times and that was it. I shrugged it off. A couple of nights ago, I came home from work and parked on our street (slight downgrade) instead of the driveway, and an hour later when I started it to go somewhere it 'boomed' again, but louder and the floor pan shook. I parked it in the driveway and left it there.

I don't think it was a backfire because it was very muffled. I've never heard one sound that way. My concern is that, about 6 months ago, the fuel pump was replaced with an imported item due to cost (Luminas have an insanely expensive 'fuel module' that goes into the tank). Can there be some kind of arcing going on in the tank causing the booms? If that were the case, can't the whole tank blow up?

Am I thinking too deeply about this? Has anyone had a similar situation? Any ideas appreciated.

Harold

[Plymouthy Adams]

I personally feel if a booming was inside the tank you would not be reporting this..and if this is your suspicions..I would never driver that car unless the tank is totally full of fuel as it will perhaps not explode but just rupture..

recommend you place your hand above and feel for hoels rips on the top fo the muffler...maybe inspect with light and mirror..the muffled may be the proximity of the muffler and heatshield/body floor

another note..look also for abnormal bulges especially at a seam..the ingest of cool air between the inner and outer chambers internally could also give you a muffled boom ..odds are it is just a matter of time before the muffler is split along a seam..

Edited November 22, 2009 by Tim Adams

[Norm's Coupe]

As mentioned, I would check out the exhaust system first. If that's not it though, I think I'd take the car in and at least have it checked out. I had a 95 Lumina APV van until late August. Never had that problem with it in the 12 years I owned it. For what it's worth though, that gas tank was a plastic one.

[JerseyHarold]

Thanks for your responses so far. Can I have a leaking injector that drips gas, which then gets sucked into the exhaust and ignites along the way? FWIW, the car started and ran normally today.

[Plymouthy Adams]

you can have anything..at shutdown the rail retains its pressure...if leaking injector you will see the fuel pressure bleed off quickly...you could easily guess yourself into oblivion.. without testing..you are still just guessing.