knocking noise in engine

mideastmafia · 07-22-2001, 10:31 AM

when i start my car and it sits at idle, i get this noise comming from the area around the timing belt cover. its a knocking noise that sounds like it could be a belt hitting the plastic cover or something of that sort. i have just had all belts replaced and tensioned. the car did this even BEFORE i had the belts fixed though.

what could it be? the car is a 1985.5 944. does my car have the tensioner built in?

thanks,
SHAUN

lordgrommit · 07-22-2001, 12:51 PM

don't know but I have the same kind of noise in my 951 esp when cold.

Matt

mlue · 07-22-2001, 02:47 PM

Shaun,

I had the same problem with my car a few months back. Belt slap is the problem, caused by loose timing belt and /or warped timing belt cover. I had the problem with the old timing belt on my car. I troubleshooted the problem by adjusting the belt a little tighter (taking up the slack in the belt) and things were back to normal. I knew the belts, water pump, tensioners and rollers required replacement so I had it all replace. The belt slap returned after 100 miles after the servicing, it seems the new belts stretched, the mechanic that worked on my car was not ever fazed by this he just retensioned the belts and everything has been fine since. My mechanic says the the belts that are made in the US seem to initially stretch a little quicker when new than the Porsche originals but after retensioning they should be fine. Watch your temp gage the engine will also run a little hotter when the tension is too loose.

Mark
86' 944NA

wolfrpi · 07-22-2001, 02:49 PM

I believe only 87 and up had the tensioner. Also, the tensioner is not self sdjusting after you have tightened it - so it should be adjusted after 2k I believe.

------------------
Erick

http://www.pelicanparts.com/cgi-bin/pmpre/pm.cgi?action=display&login=aka_951

mlue · 07-22-2001, 02:54 PM

Shaun,

If you take off the timing belt cover and start the engine you will see the belt slapping. Even after replacing a timing belt at a Porsche dealer you are required to retension it after a specified milage. Each dealer seem to have a different milage mark to do this.

Mark
86' 944NA

mideastmafia · 07-23-2001, 09:43 AM

thanks alot for your help guys.. im taking it in today.

SHAUN

mideastmafia · 07-23-2001, 11:09 AM

ok, when i heard this knocking, it was during a cold start. i just took it to my mechanic (the engine was warm) and it stopped doing it.. if it was the belts, then wouldnt it do it all the time?

SHAUN

EGSMachine · EGSMachine's Garage

i just want to see if my IP shows through Zone Alarm.
thanks,
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EGSMachine · EGSMachine's Garage

Quote:

Originally posted by EGSMachine:
i just want to see if my IP shows through Zone Alarm.
thanks,
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Boy, that sux.

Gota NoNo, man?
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mlue · 07-23-2001, 11:27 AM

Quote:

Originally posted by mideastmafia:
ok, when i heard this knocking, it was during a cold start. i just took it to my mechanic (the engine was warm) and it stopped doing it.. if it was the belts, then wouldnt it do it all the time?

SHAUN

Once things warm up the engine expands and the belt is more pliant.

Best of luck!

Mark 86' 944NA