Bluey964

As per the title I've got a worrying clunk when going over low speed bumps (eg over speed bumps) that is coming from the rear. Car is a 90 C4 cab, with Bilsteins and H&R green springs on it. At the same time a 21mm rear anti roll bar was fitted to reduce understeer. There was a clunk before the H&R greens were put on 18 months ago (Bilsteins were fitted 7 years ago, about 15k miles on them) but didn't seem as bad.

Local independent can't see anything obvious - have checked:
-top and bottom strut mounting
-anti roll bar drop links
-springs themselves
-silencer components (checked and one of the brackets for secondary muffler was broken last year and now fixed)

Am wondering if the engine mounts could be causing it, or the engine carrier split where I can't see it?

What else could it be - starting to worry me as clunks can only get worse and lead to something breaking!

Rocket Rob

When I hear clunks, I think of worn or loose anti-roll bar bushings or engine mounts. I would look at your suspension mounts which you have already done.

altarchsa

busted shock?

Computamedic

Iain,

I'd have a look at the engine mounts. They always seem to go unnoticed (and unloved) but they seem to deteriorate pretty badly and can cause all sorts of problems when worn. If you try to put your finger between the mount and the bit attached to the engine carrier you will see what I mean. If you can get your finger in that gap easily the mounts are toast.

I bought some 993 mounts off eBay last year and they made a HUGE difference - particularly on gear changes. Certainly worth a look.

Regards

Dave

Bluey964

Don't think it is the shocks as warmfuzzies and myself checked them when changing the springs last year.

I also replaced the old engine mounts which were shot with better ones I got second hand off ebay - maybe need to go and replace with the Boxster/996 mounts which other people has shown work and much cheaper than the 964 part number. The newer ones I put on there had about a 1/2 finger gap when they went on, compared to over a finger on the old ones.

Also I replaced the antiroll bar bushes when I fitted the new anti-roll bar - I think I may take off the undertray and check the fitting of them and tighten up the mounts over the bushes.

All in all a bit of a pain but sure will get it fixed with help from here!

ian89C4

You may check the flap inside your heat control box. The piece that connects the body to the heat exchangers via the heater hoses (usually orange in color). the flaps in mine would rattle around a little bit, like when shutting the door hard they would make a 'tinging' sound when they closed. They could have also made a sound going over bumps slowly, just something you may check.

Good luck!

Bluey964

Not the flaps - know the sound you mean and definitely more of a bass like clunk...not a treble like ting! Just checked the engine mounts and don't look too bad - but may put a set of 993 ones on there once one of my clients eventually settles their invoice!

Will probably take it to my local independent to get it on a lift soon - the wife is complaining which isn't a good thing, especially as working on the other car at same time (just swapped suspension on that!).