THUMP / CLUNK Sound by the gas filler door

[Kitaka]

Every few minutes I hear sound like a valve or door shutting from the left rear gas tank area. Anyone familiar with this issue that can guide me to the solution?

Not knowing if it's related...... I sometimes get a check engine light in the morning only. Once the engine is hot the check light goes away...but the clunk sound continues

 

[pgilliam1]

Strut - Motor mount - ? Need more info. Does it happen whe you hit a bump, when you're standing still, motor running, etc. ?

 

[shawn110975]

+1 on that, is it while you press the gas you here this clunk or is it when you release the clutch while in gear? little more info would help.

 

[Kitaka]

The sound occurs anytime the engine is running after a few minutes. It's not related to suspension/motor mounts/frame. It's like a purge tank thud of some sort.

 

[EdinKali]

Check your coolant res. tank and cap. Watch for burps and look for any leaks.

 

[pgilliam1]

So everything is running OK. Engine temp, oil pressure, oil level, tranny oil, etc. It sits there, at idle, and makes this "clunk". Check your gas cap and make sure it's tight and it's rubber seal is intact - .
Happy Motoring!

 

[cosmod250]

Isn't there a valve or flapper in here (plastic air intake) that can make a noise? I notice a very slight sound (bump) once in a while at light throttle application when standing still.

Peter

 

[Kitaka]

Coolant system is fine. no leaks, cracks, etc. Same for gas cap rubber. I'm going to reseach the shop manual diagrams in further detail and will let you know what I find out.

 

[Jett]

Do you have the correct gas cap installed?

 

[Hugh]

I've never heard any of these bizarre sounds. Probably because I have the Maiden blasting at 110dB whenever I'm driving Charlotte. :biggrin:

 

[Huck]

Start car and remove the fuel filler cap. If noise happens again--it is probably not fuel system related ---you will probably get an engine check light but that's ok. Your fuel tank--system is supposed to be a closed system but you could have a hose leak within the sytem.
Another possibility can be related to the muffler and temperature. Sometimes you can have expansion to metal due to heat ---if your have rust damage within the muffler---strange noises can occur as baffles move. You could also have a muffler shield with a crack in it that will expand and contract making a noise. However, once the engine is up to normal oper temp, new noises should stop.
Service tip for noise,-----cut a length of old garden hose about 2-3 feet long and use it as a probe while holding the other end to your ear. It works kind of like a stethascope. I've use a 2' dowl stick to help find strange noises by placing one end on different areas of the car/truck like engine block, alt, ps pump, compressor pump, etc. Huck

 

[Kitaka]

Great idea! I'll try removing the gas cap and see what happens

 

[Kitaka]

After removing the gas cap the thump went away.....but the "Check Engine" light did not activate as expected. It appears that the problem lies within my emissions evap control system. Thanks to all who provided input. I have more research to do this winter it seems