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Engine noise making me nervous...
I have a 78SC that makes quite a bit of noise upon start up which lasts until the engine warms up to normal operating temperature. Its a tapping noise that sounds as if it comming from the fan housing but I cant be sure. I think it may be the alternator or possibly the valves need adjustment. Could it be the chains are worn? I have gotten alot great info from this BBS. This is my first porsche and any thoughts would be most appreciated.
[This message has been edited by Kemo (edited 07-25-2000).] |
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07-25-2000, 02:20 PM
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I would suggest trying to locate the source of the noise down to a subassembly, or region, such as upper valve cover, cam chain housing, engine block, etc. You could use the wooden dowel method, or long screwdriver against the ear to localize the noise.
Does your engine have the updated pressure-fed chain tensioners? ------------------ Warren Hall 1973 911S Targa |
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07-25-2000, 02:36 PM
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S-man, I do not have the updated chain tensioners. I have that upgrade planned in the near future. I'm just real concerned about destroying the whole engine. What does it typically cost to have the tensioners updated? Is this a project one could do themselves or is it best to leave it to the pros?
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07-25-2000, 03:27 PM
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Just wondering...
Did it start all of the sudden for no apparent reason? Did it start while the engine had been running or did you just start it one day and it was there immediatly after starting it. Did it start after or during some other event that you can remember such as a stoplight race, or backfire, or engine getting too hot. Has it been getting worse? Is it a ticking noise, Rapping noise, Knocking noise? Is it perfectly in sync. with engine rpm, and constant, or does it come and go for a while until the engine heats up? [This message has been edited by leon (edited 07-25-2000).] |
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07-25-2000, 03:59 PM
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Leon, It has made the sound since Ive had the vehicle, (5months) it has gotten worse. It is a consistent rapping sound that tends to stop around 2300 rpms and is really evident at idle. The pace increases with rpms. The noise gradually goes away as the engine heats up. It doesnt go away all together but is at a minimum when engine is warm.
[This message has been edited by Kemo (edited 07-25-2000).] [This message has been edited by Kemo (edited 07-25-2000).] |
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07-25-2000, 05:52 PM
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Sounds like a worn chain.
Use a long screw driver on both chain covers. If it is a chain rattling, it will be much louder than the other side. I had my tensioners updated and it cost me about $700 total. Good luck, ------------------ Leland Pate ___79 SC Targa |
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07-25-2000, 06:06 PM
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Kemo,
If you are reasonably careful and handy with hand tools, then you can do the tensioner update yourself. Since yours is a '78, you also need the new, double bushing chain wheel carriers, too. And, I would recommend it as a 1st priority project! If you don't already have Bruce Anderson's 'Porsche 911 Performance Handbook,' get a copy ASAP! The 'noise' may be directly related to one of the tensioners. That is why I suggested trying to localize the area the noise is coming from. To get an idea about the work involved in the update procedure, and the questions that have arisen, do a search on 'chain tensioners' and read up on some of the previous postings. ------------------ Warren Hall 1973 911S Targa |
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07-25-2000, 10:59 PM
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