I Hear A Clunk Noise Under Driver Side Over Bump?

KAYSTER500

MEMBER
2004 VOLVO XC90
4 CYL
AWD
AUTOMATIC
76,000 MILES

From time to time when I go over a bump or dip in the road I feel/hear a thump (like bar) hitting under the drivers side of car down by the gas/brake pedal.

It's hard to duplicate the noise for the dealership or tire shop as it occurs periodically.

2 Replies

JIS001

MECHANIC
3,411 POSTS

Ahhh yes! My favorite complaint first thing in the morning after a good cup of joe :) (being sarcastic LOL)
Just when we think we have found the root cause of this noises something else is makaing a noise? Whatever the root cause is, the repair is going to be expensive. Here is a list you should have looked at for possible noise. Check the sway bar end links for noise. If they have play you will get a noise there. Check the lower control arm bushings. The rear ones end up splitting, causing some noise. Check the control arm bolts to verify they are torqued down. If they are not, the noise is more noticeable when backing up, braking and turning. Remove the rear bushing bolts and inspect to see if they are bent. BUT! This could also be caused by the brake pads. If this is the case, remove the front pads, clean the contact points and grease. Also check the rear subframe bushings. Get a pry bar and pry up and down on the bushings. Sometimes you get a slip knock from there, meaning the bushing is slipping and trust me, you will know right away prying on it. Also check the strut upper spring seat. To really look at it you would need to actually remove it to inspect. If it is broken all the way then you know that is the problem, BUT! Sometimes they only have a small crack at the bottom and it is enough to make noise so that is why you need to remove the strut and separate the spring seat for inspection. And the one that gets us at the end, is the strut itself sometimes makes an intermittant noise as well. To try and properly diagnose this, the chassis ear would need to be installed but sometimes that can be misleading since sound travels all over the place. Now there can also be other stuff but start with the list first. I hope this helps and keep me posted. To actually take apart some of this stuff to inspect you are going to get charge. It is time consuming and noises are one of the worse to diagnose. Good luck and I hope they are able to isolate the noise. If you need any advise let me know.