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944S cam chain tensioner failure question
OK,
This is my first real venture into the 944 realm so I need some insight here. This car belonged to a family member and I picked it up cheap. They we driving it one day and it just stopped running. They pulled over to the side of the road, may have tried to start it but they had it towed to a local shop. The shop looked at it and said it was the timing belt that failed. This didn't make sense being the belt was done 18K miles ago (107K mialeage). I started doing some research and found it was very common for the chain tensioner to fail at 125K. Which ironically that's the exact mileage of this car. I took the valve cover off this morning and found it was the Cam Tensioner that failed. upon further inspection I found the top cam has 3 maybe 4 teeth broken or gone. The lower cam looks fine. I know the sure way to find out if I have bent valves is to do a leak down test. But I figure I ask first here, what are the chances I DIDN'T bend valves? Does it always bend them or is there times when it doesn't???? Let me know your experiences and opinions....  
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Randy 1987 944S (another project),1968 912 (project in the works),1999 911 (996) (sold),1971 911E (sold),1986 944 Turbo (sold) |
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04-09-2019, 09:34 AM
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Join Date: Sep 2011
Location: Florida
Posts: 1,949
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If the belt broke you will have bent valves, it’s just a matter of how many. The reasons it broke could be many including old age (regardless of mileage), failed rollers, failed tensioner, oil leak, water pump, balance belt taking it out, no re-tension after swap, etc.
On a positive note it’s a good opportunity to refresh the head.
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Mike A 9TECHNIK | TRANSAXLE ÄRA 1986 944 (Street); 1986 944 (Track); 1986 951; 1989 951 (3.0L 8V); 2000 996 Cab. |
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04-09-2019, 09:54 AM
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Join Date: Oct 2002
Location: Boulder, CO
Posts: 1,197
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Ahh you never know. Some people get lucky. Since the cams gotta come out regardless it's easy to check though. Pin the crank at 90 degrees from any TDC and check leakdown with the cams out.
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1987 928S4 1992 968 cabrio 2009 957 Cayenne GTS |
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04-09-2019, 11:13 AM
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Location: Upton, Massachusetts
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I have a 944S head that has a damaged cam journal, but would be an excellent source for parts while refreshing your head. Would be happy to sell its at a fair price, PM me if you are interested.
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04-09-2019, 01:00 PM
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You're lucky. The tensioner usually gets ripped off the mount, this requires a new head or mucho finesse to re-weld, re-machine and heat treat the head to relieve the welding stresses. I'd count my blessings and talk to bananna944 for parts. Concerning your cam damage 944online offers a cam tooth replacement service. YMMV
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Red 84 w/25,xxx miles Stone Gray 89 S2 w/90,xxx miles Last edited by jhowell371; 04-09-2019 at 01:25 PM.. Reason: added info |
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04-09-2019, 01:19 PM
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Thanks for the info....
Quote:
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Randy 1987 944S (another project),1968 912 (project in the works),1999 911 (996) (sold),1971 911E (sold),1986 944 Turbo (sold) |
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04-09-2019, 02:14 PM
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OMG another project
Flashback
