Mystic sound from the front when hitting 80mph

[autoconnoisseur]

Hey all!

I took my C4S for a spin yesterday and all of a sudden the road just opened up and traffic was no longer an issue.

But all of a sudden my happiness ended when I heard a "burring" sound coming from, what I believe, the front differential. This sound only appeared when I hit 78 - 80mph. Can my car due for a oil change in the front diff? My car has done 30540 miles.

Another thing I discovered is that there is a clunking sound from the front right tire when I change gear. This might have to do with it as well...

I will have it checked up by a mechanic but I just wanted to check if this might be a common issue for this model.

So if anyone might know what its all about, please post a comment;)

[wvicary]

These noise are difficult to trace down over the net. It could be something as simple as a tire or a wheel brng. I doubt if the differential fluid is at fault.

[kbrandsma]

I had the same thing happen to me this summer in my 986. After a careful anaylsis I found a piece of my plastic undercarriage cover had cracked and would dangle and vibrate at 80+ mph.

Edited December 15, 2009 by kbrandsma

[autoconnoisseur]

Thanks both of you for your comments.

I´ll check both things up. Pretty sure its a minor thing... or I hope it is! B)

[neilmcf]

I'm taking my 02 C4S with 48k to the mechanic for the exact same issues in the morning. It has been happening to me over the last few years the front end rattle/mystic noise... the front end creaking noise started a few weeks ago and hoping it will help diagnose the problem. Look forward to hearing more on the issue.

[Slideorama]

guys check the plastic battery cover is locked down properly.

I had a funny "wheel bearing" type noise coming from the front of the car, at different speeds it would improve or go away...after much checking I removed the plastic battery cover and found only one "lock" was securely fastened fastened.

I removed the cover and refit it ensuring the locks were secure and haven't heard the noise since.

hope this helps,

Slide