Rep Power: 0

Our 02 V+Civic has about 140K. My daughter just experienced a highly unusual problem and I was able to confirm her symptoms when I took a test drive. While driving at a steady state 35 - 40 mph with light pressure on the gas (cruising, not accelerating or decelerating), a fairly loud vibration (like a drum beat) will suddenly occur from the right front wheel region. It is mostly audible but can also be felt in the steering wheel. It sounds like a rapid fire (3-5 times per second) drum beat (bup, bup, bup, etc.) at a lower frequency, compared to a rattle or bearing noise, which is at a higher frequency. It is very noticeable. As soon as you lift off the throttle, the vibration/sound goes away. Does this mean it is driveline related? It occurs going straight forward, not while turning. Hence it would not appear to be related to the CV joint. The noise is not like a worn bearing. I am a pretty experienced home mechanic but have never experienced this symptom in any car I've owned, FWD, RWD or 4WD. Has anyone experienced anything like this or has some thoughts on the cause? Thanx!

 
Rep Power: 314

Strange. Never heard of anything like that. How did the suspension check out? Auto or manual?

 
Rep Power: 0

I haven't had a chance to look at it as this happened at dusk tonite. And I leave for Maine tomm'w. So it looks like I will ground the Civic until I can get my indy to check it out, maybe MON. These are some pretty weird symptoms. But I am happy that my daughter picked up on it and brought it back for me to check it out. And her characterization of the symptoms were accurate.

And it's a auto.

 
Rep Power: 314

Start with normal suspension checks. Tie rods etc. I just find it strange that it's only at a certain speed with the accelerator on... If the suspension checks out check the motor mounts and go from there. Transmission.. maybe? I don't know sorry not much help.

 
Rep Power: 0

I thought I might have something causing an imbalance in the wheel that is speed related but it doesn't happen every time at that speed. I will remove the wheel this am and report back.

 
Rep Power: 314

Possible.. Maybe an imbalanced wheel is causing something loose in the suspension to knock.. But why would foot on the accelerator have anything to do with that?

 
Rep Power: 0

Pulled the right wheel and this is what I found based on a visual inspection. I also pulled the driver's side to do a comparison.

Nothing unusual WRT the wheel. No caked mud or large stones embedded into the tread. So this does not appear to be a wheel imbalance issue (unless I threw a wheel weight).

A visual inspection of the suspension reveals nothing obvious. The CV boots are all in good shape. All ball joints appear to be fine. No leaks are obvious and no grease is present. However, when looking at the rubber bushing on the lower A-arm, it appears that the rubber is cracked on one of the rubber bushing webs. The drivers side looks fine. This crack might change the stiffness of that A-arm pivot joint, allowing for it to vibrate at a specific resonant frequency. That is all I can see at this point. Hence I will send it in, since I can't (won't) replace a bushing anyway. We'll see what my indy says. Thanx for all the feedback!

 
Rep Power: 314

Hmm.. Ok if it's not cracked right through it should be okay. Mine had a dozen hairline cracks but still functioned normally when I replaced it. I ended up getting energy suspension polyurethane bushings. They last forever if you can handle the squeaking.

 
Rep Power: 201

ding ding ding, we probably have a winner. When I got mine it had the exact same symptoms. It was so intermittent that I couldn't pin point it. It was my little sisters and she dealt with it for a year or so previous. While she had it I put new rotors on it, (suspected balance issues), she put tires on it in the meantime, the cvs were fine, I replaced the struts when I bought it (because of noise). I rebuilt the trans (I bought it with it out), so I had the differential and it's bearings in my hand. None of these fixed it.

All the while the control arm pancake looking front mounts were cracked. This is the only problem I ever identified. I replaced them with rubber once and it fixed it. (I recently upgraded to ES, won't crack again in a couple months and the "feel" is better.) I suspect that marginally in range alignment specs are allowed to go way out of spec when the bushings are shot... Not able to verify this for sure, but my mechanical experience makes this the best theory...

 
Rep Power: 314

There ya go.. from a guy that knows his $hit

 
Rep Power: 0

Followup & Conclusion:

So I sent the car in to my Indy for an assessment. His opinion was to replace the front axles as the CV joints were beginning to show some wear (@140K+). He felt this was more likely the cause than the cracked bushing. He did this (for about $500) but the problem remained (at least the front axles are now fine!).

I directed him to replace the front arm bushings (for about $120) and Voila! The problem has stopped. I suspect that the reduced stiffness of the cracked bushing allowed the suspension to resonate at a specific frequency, hence the unusual symptoms. So JohnDeereBones gets the prize! Thanx for all your assistance!