Leakdown howto
04-30-2002, 03:01 AM
#2
Racer
Join Date: Jun 2001
Location: SK, Canada
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You need a leakdown gauge that attaches to an air compressor. You can get one at many Porsche parts vendors for fairly cheap. It has a gauge for the pressure you pump in and another for the air that is leaked out. You screw it into the spark plug hole of a cylinder at TDC and pressurize it while making sure the cylinder stays at TDC. You can listen to the exhaust and intake manifolds to tell where the air(if its a lot of leakage) is going. Of course if you are losing alot of air and you can't hear any thing through the manifolds its probably going past the rings.
It's a good idea to give the car a good thrashing before you test it to try to remove any carbon buildup that might stop a valve from seating fully. I've heard some people say do it with the engine cold, like a valve adjustment, and some say to do it warm, so maybe someone here can give us the skinny on that.. and anything(everything?) that I missed.
It's a good idea to give the car a good thrashing before you test it to try to remove any carbon buildup that might stop a valve from seating fully. I've heard some people say do it with the engine cold, like a valve adjustment, and some say to do it warm, so maybe someone here can give us the skinny on that.. and anything(everything?) that I missed.
04-30-2002, 10:33 AM
#3
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John
Snap_On's version, bit pricey $280:
[URL=http://buy.snapon.com/catalog/PRO.asp?SUB%5FCat%5FID=945752&SUB%5FCat%5FNAME=Cylinder+Leakage%2FEngine +Vacuum%2FFuel+Pump+Gauges+And+Tester&Cat%5FID=945483&Cat%5FNAME=Diagnos t ic&group%5Fname=Cylinder+Leakage+Tester&store=snapon%2Dstore
Try a google search as I know they are available through other parts suppliers. Do the test warm and I recommend a compression test too. Even doing these tests, the broken head stud on my engine did not cause significant leakage. I measured 5% across all cylinders. Perhaps more pressure would 've detected the problem. Good luck, hope its not a significant problem
Snap_On's version, bit pricey $280:
[URL=http://buy.snapon.com/catalog/PRO.asp?SUB%5FCat%5FID=945752&SUB%5FCat%5FNAME=Cylinder+Leakage%2FEngine +Vacuum%2FFuel+Pump+Gauges+And+Tester&Cat%5FID=945483&Cat%5FNAME=Diagnos t ic&group%5Fname=Cylinder+Leakage+Tester&store=snapon%2Dstore
Try a google search as I know they are available through other parts suppliers. Do the test warm and I recommend a compression test too. Even doing these tests, the broken head stud on my engine did not cause significant leakage. I measured 5% across all cylinders. Perhaps more pressure would 've detected the problem. Good luck, hope its not a significant problem
04-30-2002, 05:31 PM
#4
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John,
Summit racing sells a pretty decent one.
Part #TAV-08015 for $74
Made by Tavia
Here is a link to it..
<a href="http://store.summitracing.com/default.asp?target=search.asp%3FType%3Dbykeyword%26Part%3Dleakdown%26Sea rch.x%3D1%26SearchType%3DBoth" target="_blank">http://store.summitracing.com/default.asp?target=search.asp%3FType%3Dbykeyword%26Part%3Dleakdown%26Sea rch.x%3D1%26SearchType%3DBoth</a>
Hope that helps..
Norm
Summit racing sells a pretty decent one.
Part #TAV-08015 for $74
Made by Tavia
Here is a link to it..
<a href="http://store.summitracing.com/default.asp?target=search.asp%3FType%3Dbykeyword%26Part%3Dleakdown%26Sea rch.x%3D1%26SearchType%3DBoth" target="_blank">http://store.summitracing.com/default.asp?target=search.asp%3FType%3Dbykeyword%26Part%3Dleakdown%26Sea rch.x%3D1%26SearchType%3DBoth</a>
Hope that helps..
Norm
