1999 C4 Transmission and Strange Noises

[Mdelay]

Howdy All-

I’m obviously new here, been lurking around for a while but after a Christmas Eve miracle (finally bought a Porsche) I figured it was time to actually become a member.

I bought it with some known issues that were easy to diagnose, as well as easy to fix. What’s been done- new wheel bearings up front, new shocks on all four corners, parking brake switch replaced to get the top working, rebuilt the top hydraulic actuator after realizing it had a significant leak.

Now it’s time to tackle the not so obvious issues. I’ll start by saying, the car drives great, it shifts perfectly (even into second), the clutch feels fine, it engages with minimal movement. So, every issue I’m about to describe is noise, I’m not feeling anything in the hands, feet or seat.

First, there is a dry bearing sound coming from about the front seat area and also possibly forward of there. After removing the belly pans, I noticed the u-joint on the drive shaft is slinging a bit of grease. Is this normal? Or could this be one of the noises I’m hearing?

Second, and most important, there is a clanking, thumping or rattling sound from behind the cabin of the car while decelerating with the clutch depressed and the shifter in gear or in neutral. The frequency Of the sound slows as the car slowed. Also, the trans just seems loud to me, but I really have nothing to compare it to. What is normal?

After the drive I drained the trans, the oil looked clean and had been serviced with the proper amount. I did discover some of the silver grease on the magnet.

Here’s where i could use some guidance, I know this silver grease is an indicator of a failing bearing in the trans, which could be the loudness I’m referring to. However, there wasn’t a huge amount of it like I’ve seen on YouTube. Do I have some time? The clutch feels great but I’m thinking the sound that slows as the car slows might be a throw out bearing… what would you do in my shoes? Should I bite the bullet have the trans rebuilt, throw a new clutch and components at it? I’m not opposed to spending some money on necessary repairs but don’t want to needlessly spend money either. Or, am I barking up the wrong tree and just need to check the muffler bearings????

I would appreciate and guidance you have to offer. I know its hard to diagnose based on my written description of sounds, so I thank you very much in advance.

Prost,

Michael

[Van B.]

Michael,
You need to pull the transmission and inspect the clutch components first. And then also your cv joints. You will know a lot more after that.

Van