Hello --

On my 2006 Accord 4 cyl SE (55k miles, mostly highway), I hear a sharp noise over bumps that seems to come from the left front. The noise is more like cracking rather than a thunk. It doesn't happen all the time but is sometimes severe enough to be frightening. This started about 2 months ago and has been getting worse. It seems to have started sometime after I had my tires rotated. I had the lug nuts retorqued but this didn't help.

There is a second noise that may be related. Sometimes when the car is being started but just in the split second before it actually starts, there is a sharp noise that almost sounds like a knock. It seems to come roughly under the driver foot well. However, it doesn't occur at any RPM after starting (just sitting and revving). This also started about 2 months ago. I thought this might be a loose heat shield or something similar.

Except for these noises, the car seems to drive normally (no vibration).

My mechanic (not a Honda specialist) couldn't reproduce either noise. On the lift he couldn't find any problem with the front suspension. His best guess was that there might be a problem with the steering rack ($1000 to replace with no guarantee that this would solve the problem). I'm skeptical because 1) I can't feel any difference in the steering, and 2) a google search didn't seem to find anyone else with a failed steering rack.

I'm going to try to record these noises on my cell phone. In the meantime, thanks for any suggestions.

Don C.

 

Could you please provide a little more information regarding weather conditions, whether turning or driving straight or anything else that you might think does not matter when I fact it may help diagnose the issue. It sounds like they are two different issues. The cracking while drive may be as simple as a dry ball joint, but if it is really cold out when it happens it could be the shock. Thanks and welcome to HAF.

 

The cracking sound is most noticeable when driving generally straight (i.e., not going sharply left or right around street corners) at typical suburban or interstate speeds. It doesn't seem to be affected by the weather (40F - 60F, typical Baltimore fall weather).


How would a dry ball joint be diagnosed? My mechanic said that he couldn't find any significant play in the suspension.

 

If it is a dry ball joint often times there is no play in the joint. To diagnose it takes the car being off the ground, noise to be at a minimum and one person under the car listening to each joint and one person turning the wheel from lock to lock. If a joint is dry it can usually be heard. The other thing that I would look at other than ball joints is the front lower control arm to sub frame bushings and the sway bar links. Note that the only consistent way to diagnose a sway bar link is to take all load off the sway bar. None of the above should create the noise you are hearing at startup.

 

It had snowed yesterday so my mechanic had only taken a limited test drive. Today his test drive was more extensive and he was able to hear both noises. He found a broken transmission mount and a broken motor mount. He couldn't explain the cause except possible deterioration with age. The repairs have not yet been completed.

 

Funny you posted back with that because I was just thinking that upper front left mount, if shot, could create a noise that would be frightening enough for someone to not want to drive, but it will be variable dependent on the load on the engine. It can also most definitely cause a noise at startup as the engine is torqued when the starter engages. Please post back the the HAF community and let us know how you make out after the repairs are complete.

 

Based on a 6 mile drive over moderately bumpy roads, the problem seems to have been solved.