Wierd V6 Bora 4motion Issue

[MRJZ]

Well, to start, I have only ever seen 1 thread on VORTEX dedicated to this, so I am not having much luck.

The issue only happens during heavy rain.

I begin to get a massive knocking sound just under my gear shifter.

I dont know if there is a bush under there, maybe around the exhaust or gear box that goes weak under wetting but FUK it is annoying.

Can anyone help with an answer?

Jim

[Bora Sport]

I have noticed this on mine usually only when I have perhaps let the revs get a bit low going up a rise. If I change down it goes away. My mate who is a VW guru and he owns an R32 told me that it is a well known symptom of the 4motion models. He suggested to me that the school of thought was that the exhaust pipe twists due to uneven temperature due to water splashing up onto it. It then connects with the underbody of the car under the movement of the engine.

Whatever it is he reckons it is not something to worry about. I have only had it happen 3 or 4 times in 90,000k's.

[Jmac]

If this is a "common fault" there is no technical service bulletins for this , so where is this info gathered??? I did have a 1.6 Golf do something similar but it was much like Bora sports symtoms and not rain, it ended up being a maladjusted exhaust from factory. There was a special measurment to follow. The exhaust has marks on it for alignment. I would therfore tend to try and drop the exhaust ever so slightly going by this theory. Doesnt take much to upset the harmonics though.
Jmac

[qsilverza]

I had heard a few things on the vortex forums about cars with the 4motion drive line doing some interesting things in the rain, I think it was a knocking...

[Bora Sport]

Just to add to my previous post. I have been under the car whilst it was on a hoist many times. I cannot see how anything can hit anything under there. But apparently it does???