Jackhammer Noise from Engine Bay!
#1
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Jackhammer Noise from Engine Bay!
A few days ago while driving along the freeway, I heard a sound like a jackhammer coming from the engine bay of my 993, so startling I almost soiled my linen. It immediately made me think "Expensive Engine Noise" and "Engine Rebuild Time". Then the noise stopped as suddenly as it had started. But it came back again a few minutes later. I stopped and looked in the engine bay, but saw nothing amiss.
When I got home, I put the car on stands and crawled underneath, checking everything I could think of, including CV joint bolts, but found nothing.
The next time I drove the car, the noise came back. I stopped, opened the engine bay, and saw that the plastic cover of the spoiler drive was moving in time to the noise.
When I took the cover off, I could see that the transmission cover had separated. Further investigation revealed that the "closed" stop limit switch didn't quite make contact when the spoiler was fully retracted, so the drive kept powering even though the spoiler was all the way down, causing stress that damaged the transmission. The horrible noise must have been the gears in the transmission jumping teeth.
So now I'm looking for one of these transmissions, part# 964 624 121 00 to use for parts to repair my defective one, so not working is okay. If you have one, please PM me.
When I got home, I put the car on stands and crawled underneath, checking everything I could think of, including CV joint bolts, but found nothing.
The next time I drove the car, the noise came back. I stopped, opened the engine bay, and saw that the plastic cover of the spoiler drive was moving in time to the noise.
When I took the cover off, I could see that the transmission cover had separated. Further investigation revealed that the "closed" stop limit switch didn't quite make contact when the spoiler was fully retracted, so the drive kept powering even though the spoiler was all the way down, causing stress that damaged the transmission. The horrible noise must have been the gears in the transmission jumping teeth.
So now I'm looking for one of these transmissions, part# 964 624 121 00 to use for parts to repair my defective one, so not working is okay. If you have one, please PM me.
#4
Rennlist Member
I had exactly the same thing happen to me. Turned out that the drive motor for the spoiler was fine but the transmission with the cable attached had broken open and was slipping causing the pounding noise. New bearing and a lot of JB Weld and all good. If you lost the little round piece with a hole in it that supports the cable end then you are doomed for a new part. Was lucky to find mine in the driveway before rebuilding it. Spoiler mod takes a lot of stress off those parts! Good luck.