I've got this noise goin on with my Civic - I think I've got an idea on what it is, but here's the symptoms:

When I start the car up, there is an audible 'thunk' from the front end of the car. You can also feel the 'thunk' via the clutch or floorboard.

When I let off the gas quickly in most gears at 2-5k rpm, there is also a faintly audible 'thunk' that can be felt slightly through the clutch.

After the 'thunk' from letting off the gas, I'm getting another 'thunk' when I get back into the gas.

All of this happens with some infrequency - sometimes it happens, other times it doesn't, although it seems to be happening more the longer it goes on.

I think it's a motor mount problem - I had orginally thought it was maybe a clutch or tranny problem, but since it makes the noise at ignition when the car is in neuteral and the clutch is in, I've pretty much eliminated that idea. This originally happened a couple days after changing out an axle - I was hard on the gas at 5k in 2nd gear and had to get out of it quick & got the 'thunk' for the first time. A Honda shop did look at it and said my rear motor mount was loose & they tightened it, but the noise is still around.

Anyone had something similar before or any ideas other than a motor mount problem?

Thanks,
Eric

 

sounds like a mount the front mounts break when they get old

 

The best way to tell the mounts is by watching the shifter. Does it move around a lot when you are accelerating or decelerating?

When my friend's mount broke, you could put your hand about 2 inches behind the shifter, and accelerate, and the shifter would move back against your hand. His were really bad though. The funny thing is that if you opened the hood and reved it, the motor didn't move at all. No load. You couldn't even really rock it by hand, but with load on the car it moved like crazy.

 

front and rear mounts go bad first...the rear mount is a real pain in the ***... the front one can be a pain too

 

Yeah I got the same problem.


Yager-

 

another easy way to tell is to accelerate in first then lift off the gas, then accelerate again. if the mounts are bad you'll feel a kind of hesitation as the engine rocks forward and then back.