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Super Mechanic
Super Mechanic, Master technician
Category: Chevy
Satisfied Customers: 16832
Experience:  29 yrs. exp., ASE master, cert. in G.M. electrical, a/c, susspension, brakes, electronic steering
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My car keeps making a thumping sound what could it be my ...

Resolved Question:

My car keeps making a thumping sound what could it be my husband said the u joints look fine
Submitted: 8 years ago.
Category: Chevy
Expert:  Super Mechanic replied 8 years ago.

Hi TM, Super mechanic here. I just wanted to verify the thumping that you are hearing.

Is it when you come to a stop or when you take off?

Or is it a constant rhythmic thump? Thanks

Customer: replied 8 years ago.
It doesn't do it when I'm stoped but then when I am driving it seems to be constant
Customer: replied 8 years ago.
Reply to super tech's Post: It also did it one day last week and then was fine until on my way to work today it started again.
Expert:  Super Mechanic replied 8 years ago.

It is possible that one of the U-joints are having trouble pivoting. It is something that you can't see, you have to take it out and check it for smooth movement.

Does it change when you are using the brakes?

Does it seem to increase with speed?

Customer: replied 8 years ago.
I haven't noticed what it does when I brake, it seems like it does increase with speed, when it starts I slow down. It did it one day last week and did ok all weekend and then it started again today, when it did it last week I parked the car for the day and when I drove it home it was fine I don't have a lot of money and I am just trying to find out things that could make it do that
Expert:  Super Mechanic replied 8 years ago.

I hear ya'. I can' timagine having to pay what these shops want to even look at a car.

Well, we can't rude out the U-joint(s) yet but what I would like you to do is, when it happens try to touch the brake slightly and see if it either gets louder or goes away.

I want to eliminate a rear brake rotor/drum that may be doing it.

You don't feel it in the steering wheel do you?

Customer: replied 8 years ago.
I just went out and drove it around the parking lot at work, its not doing it as much as it was earlyer today,but I was't driving on the roades either. the thumping does not feel like it is coming from the brakes it feel like it is comeing from under the car but it didn't seem to make a diffrence if I touched the brakes or not.
could a j joint problem come and go?
Expert:  Super Mechanic replied 8 years ago.

It is possible for a U-joint to stop making a noise depending on the temperature and moisture in the air. It would not be very likely though. I would have them checked either way as well as the transmission mount. Just to be sure.


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