A loud thump periodically from gas tank area

Tiny
NICKDAMONE83
  • MEMBER
  • 1992 GMC VANDURA
  • 5.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 130,000 MILES
From time to time and not in any certain circumstance that I've noticed there is a thump or bang that comes from under the van. It sounds like it's in the area of the gas tank. Wondering what this is and what could be causing this? Any suggestions would be greatly appreciated and thanks in advance. Sincerely, Nick Williams
Tuesday, October 8th, 2019 AT 8:01 PM

1 Reply

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Welcome to 2CarPros.

Nick, is it something you can actually feel? Are there any symptoms that may indicate an issue with a universal joint on the drive shaft? Take a look through this link:

https://www.2carpros.com/articles/how-u-joints-work

Often times, a bad joint will be felt via a vibration at certain speeds. It can make a clunk noise or bang if bad.

Also, a very common issue is related to exhaust hangers breaking and allowing the exhaust to bang off the underside of the vehicle or a component. Check under the vehicle to make sure the exhaust is tight and doesn't move around.

One last thing. Is there anything that you can do to cause it to make the sound?

Let me know.

Joe
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Thursday, October 10th, 2019 AT 7:33 PM

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