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Hi all, new to the forums and could seriously use some helpI
I recently purchased a 2001 project car, and I've got a clunk or knocking sound when initiating accel and initiating decel. Happens immediately. Doesn't happen when hitting bumps. Doesn't happen when turning wheel. I put it on jack stands and found a questionable ball joint and replaced it. Other ball joint, tie rod ends, stabilizer links, lower control arm bushings are all in good condition and seem to hold up well to prying and prodding. Struts seem solid. Problem persists.
Car handles fantastic, holds the road great, totally stable. Except at above about 55 mph, I get some shimmy in the front end, which may or may not be related to the problem. Also FWIW when replacing the ball joint, I noticed the previous owners brake job looks a little dubious. The pads are semi pricey ceramic ones with tons of pad left. but my LF rotor has some grooving and my pedal is real spongy. So it's as if someone just slapped on expensive pads using no proper installation method whatsoever.
Every other aspect of the cars performance is totally on point. I sure could use some ideas for where I should start chasing this down. Can something in the BRAKES make noise when accelerating? What other things should I check? Any help is totally appreciated!!

 
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Does the frequency of the knock change with RPMs?

 
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No it doesn't coincide with wheel speed or engine rpms. Every time I hit the accelerator or brake, there is immediately a knock or two. At ANY speed. It doesn't do it continuously. Definitely sounds like something clanging onto something else with great force

 
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check engine mounts

 
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I will check the engine mounts. If it's mounts I should get that clunk if I shift from first to reverse and back to first, correct?

 
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Here is the diagram and part #s for the engine and trans mounts for a 2001 manual (I assume this is what you have). https://parts.sonshonda.com/showAsse...driveLine=6292

 
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Nothing wrong with putting both hands on you valve cover and pushing/pulling the engine back and forth listening for the clunk sound.

I agree It’s most likely a failed mount, but you might get lucky and find a forgotten spanner or infamous lost 10mm socket wedged somewhere.

 
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Yes it is a manual. Thank you for the link, definitely useful. I'll check mounts and update thread

 
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Good tips. I'll put hands on the motor and see if I can find any loosness. And I'll definitely check my fasteners for torque/missing pieces or a lost wrench. Never thought of a wrench banging around in there. I'll update when I have new info. Thanks.

 
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Just FYI, but once i chased a clunk for months.

This is what it turned out to be. Can be anything, really, if you strike out everything.

 
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Thanks for the heads up. You're right it could be any number of things. I've got a feeling it's gonna be a gremlin thats only gonna be found going piece by piece torquing, checking, bouncing, hammering, wiggling and banging till its weeded out.

 
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Little update. The sound does happen at cruising speed, it's just much more pronounced when accelarting and braking. I'll get under it tomorrow and start methodically working my way around the front end. Keep the comments coming!

 
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I had a clunk on my 01 civic coming from the driver's side when accelerating from a stop and when heavy braking. The noise started right after I had the subframe out of the car when changing the transmission input shaft bearing. A year later, and after replacing nearly everything in the front end with no success, I finally found the issue. Apparently the subframe should be tightened with weight on the tires, not when jacked up. I loosened the 4 -17mm bolts holding it, let the car off the jack stands, then tightened them back up. Clunking is finally gone! Another thing I did was make sure the sway bar was aligned correctly, equal distance from the control arm on both sides – loosen the 2 bushing brackets and use a pry bar to wiggle it left or right as needed. Hopefully this helps someone before replacing everything like I did. I even paid a mechanic to diagnose the noise, he had me replacing parts unnecessarily. Cheers!