Thumping noise when turning

subaru
impreza

#1

My 2003 Subaru (about 14 years old, 165K mi) started making a thumping/clicking noise only when I turn right. It had been going on for weeks when I finally I took it to the mechanic, and of course he couldn’t hear a thing. He drove it in circles, took the wheel apart, checked an axle boot that he replaced on it last summer, checked the axle. He said that the brakes squeak, but everything is fine. He told me to keep driving it until it gets worse. Didn’t charge me anything.

5 days later (today), the noise comes back. Only when I turn right. I also feel a faint vibration below my feet. I drove it to the train station to get to work, put on the parking brake like I always do, but noticed that there was a burning smell from the front end. When it was time to go home, I noticed that there was something funny about the brake pedal. I normally press the brake when I start the engine, and usually it gives. But this time, it didn’t and acted like it was stuck. I took my foot off, pressed again, and it was fine. I had also released the parking brake. Driving home, the thumping noise was gone.

Typically, this noise is worse in the morning than it is later in the day when I go home.

Any thoughts? Can a loose parking brake cable contribute to a thumping noise when turning in one direction, or are these all unrelated problems? I am stumped. Are CV joint issues typically inconsistent like this? Thank you for reading, and thanks in advance for ideas.


#2

Cautiously feel the front wheels after a drive to see if one is hotter, indicating a dragging brake.


#3

At this stage only a wild guess is possible, but my wild guess is an inner CV joint. The inner joint operates differently from the outer joint, and it can develop a wear pattern in its outer housing that cane fight the three bearing assemblies as they try to ride out of their normal wear paths in turns, which is a necessary thing for turning. Basically, the “rollers” in the attached picture ride in and out of the “roller grooves” when you turn, but rotate in a planetary motion when driving straight. It’s hard to explain verbally without getting technical, so I’ve attached a diagram of a typical inner CV joint assembly. Hope it helps.

However, with all unidentifiable sounds checking the brakes as suggested by insightful is always prudent.


#4

insightful, I’ve tried that before, and there was nothing like that, nor anything obvious that was out of whack with the front wheels, but that was a while ago. I will check again. Thanks to you and to mountainbik.


#5

The symptoms are classic for a CV joint on the fritz. If I had this problem and couldn’t get to the bottom of it by the typical poking and prodding & visual inspection, and the brakes & wheel bearings seemed ok, I’d remove the axle that seems to be involved, remove both boots, and as long as nothing looked or sounded abnormal indicating a CV joint was damaged, I’d clean & re-lube both CV joints, install new boots, install the axle and note what effect that had. Hopefully it would fix the problem. If it didn’t at least I’d have a good rebuilt axle installed which will last quite a while, and I’d know the axle wasn’t the problem. A more cost effective way if you are hiring the work out is probably to replace the axle with a new or rebuilt one.

.


#6

ok, this morning, after driving the car, the wheel on the front passenger side was EXTREMELY hot. yikes. The brake was also making a terrible noise, steadily, and would stop if I gently pressed the brake. The standard thumping sounds on right turns continued. I think this qualifies as “worse” and we’ll have to visit the mechanic again! Thank you all for the feedback.


#7

sure sounds like a hanging caliper to me, but with the age of the vehicle it could also be the flexible brake line at that wheel. As these lines deteriorate with age…they break down on the inside of the hose. This sometimes allows a piece of rubber from the hose to act as a check valve. Allowing fluid to push the brake caliper piston out, but not allowing that fluid to flow back when you take your foot off the brake.
If the mechanic replaces the caliper, I’d insist that the line be replaced because it’s just a matter of time before it does go bad.

Yosemite


#8

Overheating brakes is a high priority safety item to get fixed asap. The brake fluid can get so hot when a caliper locks up it will boil, and when that happens you’ll have no brake pedal at all. Sounds like you are on top of the problem, but be extra cautious in your driving until this is addressed.