One rotor much hotter than other 3 - cause of vibrations?

[Anker]

Don't ignore the calipers! When I had exactly the same problem on my Mercedes CLK it wasn't the rotors, but it was sticking calipers. The wheels were getting so hot that the plastic caps on the valve stems partially melted! A set of rebuilt calipers fixed the problem.

[speedyspaghetti]

Originally Posted by Anker

Don't ignore the calipers! When I had exactly the same problem on my Mercedes CLK it wasn't the rotors, but it was sticking calipers. The wheels were getting so how that the plastic caps on the valve stems partially melted! A set of rebuilt calipers fixed the problem.

Ok, this is promising. Did you feel any impact on the steering of your car when you had this issue? Is it possible to do this myself with a caliper rebuild kit? Or would it be better to just buy a rebuilt set?

[Burg Boxster]

Originally Posted by speedyspaghetti

Ok, this is promising. Did you feel any impact on the steering of your car when you had this issue? Is it possible to do this myself with a caliper rebuild kit? Or would it be better to just buy a rebuilt set?

Whoa - Hold on a minute...

You've already thrown a ton of $$ and parts / labor chasing this issue to no resolve. Reputable shops dissuade this behavior... the rest do not and keep going until your wallet says otherwise. If you've been directing them what to R&R that's one thing... If they've been leading the money parade I'd spend time learning to DIY or at the very least find a better shop.

Now, pull the wheel and inspect the caliper, pads and rotors to see if issue is there before ordering anything else. Otherwise you'll continue this expensive madness.

Post pics here if you need help.

Good luck

[speedyspaghetti]

Originally Posted by Burg Boxster

Whoa - Hold on a minute...

You've already thrown a ton of $$ and parts / labor chasing this issue to no resolve. Reputable shops dissuade this behavior... the rest do not and keep going until your wallet says otherwise. If you've been directing them what to R&R that's one thing... If they've been leading the money parade I'd spend time learning to DIY or at the very least find a better shop.

Now, pull the wheel and inspect the caliper, pads and rotors to see if issue is there before ordering anything else. Otherwise you'll continue this expensive madness.

Post pics here if you need help.

Good luck

The shops I've gone to, besides the ones that suggest wheel balancing/alignment/new tires have all said "oh well, it's not that noticeable" and give me a list of things it could be without being definitive about anything. All of thats part I replaced I did myself, so definitely saved some labor costs, although my sanity may have been affected You're right though - I'll get the car up on jack stands soon and see if I can take a deeper look at the brake assembly. I bled the system recently, which I imagine would've helped with the caliper, but I guess if it is stuck, bleeding would not "unstick" it.

[BoxsterSteve]

Not on my Boxster, but my old Forester...I had a sticking calliper that wouldn’t completely release.
I would get these crazy random harmonic vibrations that would come and go; highway speeds were the worst. The entire vehicle would start to shake... subtle at first and gradually becoming violent enough to make me pull over and stop.
Pull off the highway, stop for a bit and start driving again and sometimes the behaviour would repeat itself, but not regularly.
Took the car to my Subaru wrench and he thought I was full of **************** until he test drove it and experienced it for himself.
Yep, a bad caliper that wouldn’t release fully.
Caused a goofy random harmonic vibration through the right front/left rear brake circuit that would cause both calipers on that circuit to randomly chatter.
A new caliper and pads on the right front wheel and new pads on the left rear and all returned to normal.

[Gilles]

Originally Posted by Anker

Don't ignore the calipers!

If it has been sticking long enough, that particular pad will be 'thinner' [QUOTE]

PS: I meant to say that the pad will be thinner than the pad on the opposite wheel (but same position)

.

[speedyspaghetti]

Originally Posted by Gilles

+ 1..

Not sure about the vibration but pretty sure about the overheated rotor..

PS: If it has been sticking long enough, that particular pad will be 'thinner' but once I removed the piston and clean it (polished)
with steel wool and replaced the seals = no more sticking caliper

Fingers crossed...hopefully this is the issue. I'm probably due for new rotors anyway, so I'll probably replace the front rotors + pads, even if the caliper is the issue here.