mikstew

I went to an autocross the other weekend, and on that day my 1999 boxster developed this terrible grinding from the rear when turning at speed or under load. I've had the entire suspension checked over for play and was told it all looks good. CV shafts were checked as well.

https://photos.app.goo.gl/fMrHOSGg3PzS3LW83

Thoughts on what this noise is? It is not just a noise, you can also feel the grinding taking place. It is rather unpleasant as the video will show :P

Macster

First thing that comes to my mind is a wheel bearing.

But you have to consider something came loose and in a turn is making contact with a tire/wheel or some other part of the drive train or car.

Who checked over the suspension? Can't believe a brief road test by a tech couldn't allow the tech to identify the source of the noise.

mikstew

FIXED.

It was the front engine mount. Despite the fact that it had been replaced in the past, this mount was also toast.

Replaced the mount, problem completely eliminated.

extanker

thanks for the report back....i was thinking rear wheel bearing issues too

Aaron S.

My father is experiencing the exact same issue at the moment. How much did the repair cost you? And was it at a Porsche dealer or a local mechanic?

mmm951

I am going to try these FF1 reinforcements from Suncoast since I will be replacing my mount as well. Apparently, it will help prolong the life of the mount as it is a weak point on these cars.

https://www.suncoastporsche.com/suncoast-parts.htm

dr914

I agree probably a wheel bearing

joseph mitro

no, did you read the post? it was the front engine mount.
my car had the same horrible grinding noise under load in corners. once the mounts were replaced the noise went away

bcrdukes

For those of you looking to use the Function First motor mount inserts, I had them installed late summer/early fall and have been great, and would recommend them. Some people in other threads reported serious vibration issues at speed but I didn't experience any of that, which means those who reported vibration issues may have other problems, or did not replace the motor mounts themselves.

Keep in mind, these are only the inserts you need which replace the factory inserts, and are not the mounts themselves. I recommend replacing both new motor mounts AND the Function First inserts.

Macster

Missed the follow up but I have to admit I was quite surprised it proved to be an engine mount and not a wheel bearing. Regardless I'm glad the OP found the problem.