thumping or jackhammer like sound during acceleration at high speeds
 

Hi,

I've been having an intermittent thumping/clicking/jackhammer sound when I accelerate at speeds over about 60 mph. It only happens when I am accelerating; when I let go of the gas pedal the sound stops immediately. It sounds like something is knocking on the wheels, and I can feel the thumping through the gas pedal. Actually, when it gets really hard I can feel it throughout the car.

I've read some of the other forums, and it sounds just like this one: https://honda-tech.com/forums/honda-accord-1990-2002-2/jack-hammer-noise-back-1534926/
But I don't see how it could be unbalanced tires; my steering wheel doesn't shake. The CV boots are still intact. Could this be the wheel bearings, or is it most likely an axle problem?

I'm actually on the road going from Kansas to NJ, and it's gotten worse along the way. I already stopped once for a mechanic to look at it and the axle & joints looked solid enough. He wasn't able to reproduce the problem because it seems like the knocking/thumping only begins after the cars been traveling at 60+ mph for about 30-60 minutes. Perhaps after all the parts warm up? Unfortunately since then, the knocking is getting louder and harder, and when it gets bad there's a lateral shaking as well.

Needless to say, I've stopped for the night and will be bringing it into some nearby garage tomorrow. If anyone could recommend a garage near Richmond, Indiana, that would be great too.

Re: thumping or jackhammer like sound during acceleration at high speeds
 

Sounds like axle(s) to me.

Re: thumping or jackhammer like sound during acceleration at high speeds
 

Sounds like my daughter's complaint when driving home from FL for break. Axle boots looked fine, but outer right joint was siezing up. New axle fixed it.

Re: thumping or jackhammer like sound during acceleration at high speeds
 

I was finally able to get a couple of mechanics to look at it; turns out the main problem were the engine mounts going bad. The rubber on the front was all worn out and the fluid leaked out of the one on the side.

I'll have it changed out tomorrow, but they're suspicious that there might be another problem, so they'll test drive it again after they replace the part.

The thing is that it doesn't only lurch once when you put it into gear; it gradually increases thumping while you accelerate. I think that might be what was puzzling them. I'll post again when they figure it out.

Re: thumping or jackhammer like sound during acceleration at high speeds
 

i had a toyota that had the same problem....thing was the mech. told me that i'd spung a bearing in the engine...

it sounded like it had a BB in the engine....and it only did it when i pushed on the gas....

a week later the engine fell apart ....

i didn't get to read much on this topic but i just wanted to have my say in it....

good luck

Re: thumping or jackhammer like sound during acceleration at high speeds
 

If you find out what it is, please share it. I might have something similar.

Re: thumping or jackhammer like sound during acceleration at high speeds
 

Look at the tie rods and the rack in pinion it seems like that could be the problem....

Re: thumping or jackhammer like sound during acceleration at high speeds
 

I once bought an auction car that had a similar issue when I drove it home the first time. 2 lug nuts on each wheel. That's right...2 on each wheel. I guess they were having a shortage that week. That's what you get for $250 I guess. My fault for not checking first though...