Interior knock -cured - at last

[Paul 290T]

Hi,

This one took me a while to track down. If your 944 suffers from a knock emanating from somewhere near the centre of the dash then this might be the solution.

The dash must have de-laminated/unglued itself from whatever supports the edge adjacent to the windscreen. Maybe there's a frame beneath.

If i drove along a rutted road surface, a good example would be concrete - the type with the fine ripples, it would set a defined hollow sounding knock away. Potholes would often trigger a single knock.

I fixed it be pushing a full width piece of closed cell neoprene into the gap between the windscreen glass and the top of the dash. Being mat black the rubber "vanishes" within the surrounding mat blackness of that area. The strip of rubber was about 15mm x 15mm. It looks neat when pushed in evenly.

Of course I'd had the stereo out, centre vent out, aircon unit out, and padded everything with foam rubber to no avail before discovering the solution.

No more knocking.

Hope this helps.

 

[944Scott]

It's so satisfying curing these kind of little niggles. I had a couple from underneath the car, one turned out to be the centre exhaust heat shield missing a screw and the same with the heat shield around the brake servo this was vibrating at the bottom.

I also get a knocking sound when I drove down my drive (rough track, downhill) which sounded a bit like a worn ball joint but I think I might have cured this by replacing the lower steering shaft, it was quite worn.

 

[TTM]

The black plastic frame in the center console often develops a light but irritating rattling noise, most often heard on bad roads, which disappears if you keep your finger on it between the radio and the dashboard.