Car seems worse after new head gasket?
03-12-2004, 05:27 PM
#12
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Join Date: Dec 2002
Posts: 1,463
Re:Car seems worse after new head gasket?
Maybe this willl help.
With there being 0 compression on one cylinder, and low compression on two adjacent cylinders, I would suspect components that are common to both cylinders, like the head mating surfaces, and the head gasket.
To be really sure, perform a leak down test. There are tools for this, but you can use an air hold tool, or anything else that will let you put compressed air in the cylinders through the spark plug hole. You could even weld a male air fitting to one of those goofy anti-fouling adapters. Connect whatever tool you have or can borrow. 90 Psi should be more than plenty. Expect the cylinder to move to the complete bottom of the stroke, which is fine. Both valves will need to be fully closed!
Listen to where the air is escaping, and you will have found your problem. Air coming out of the following locations are probably due to the matching problem.
Throttle Body = Intake valves
Exhaust Pipe = Exhaust Valves
Radiator = Head Gasket
Oil filler = Rings
That should cover it!
If your compression figures were reasonable, an actual leak-down check would tell you your percentage of leak, which could be used to determine the ring or valve sealing issues. Since your numbers are so bad, there is a major problem you need to deal with, and the percentage is not even an issue at this point.
Hope that helps!
Craig @ Tuner Toys
With there being 0 compression on one cylinder, and low compression on two adjacent cylinders, I would suspect components that are common to both cylinders, like the head mating surfaces, and the head gasket.
To be really sure, perform a leak down test. There are tools for this, but you can use an air hold tool, or anything else that will let you put compressed air in the cylinders through the spark plug hole. You could even weld a male air fitting to one of those goofy anti-fouling adapters. Connect whatever tool you have or can borrow. 90 Psi should be more than plenty. Expect the cylinder to move to the complete bottom of the stroke, which is fine. Both valves will need to be fully closed!
Listen to where the air is escaping, and you will have found your problem. Air coming out of the following locations are probably due to the matching problem.
Throttle Body = Intake valves
Exhaust Pipe = Exhaust Valves
Radiator = Head Gasket
Oil filler = Rings
That should cover it!
If your compression figures were reasonable, an actual leak-down check would tell you your percentage of leak, which could be used to determine the ring or valve sealing issues. Since your numbers are so bad, there is a major problem you need to deal with, and the percentage is not even an issue at this point.
Hope that helps!
Craig @ Tuner Toys
03-12-2004, 05:34 PM
#14
1.0 BAR
Thread Starter
Join Date: Jan 2003
Posts: 375
Re:Car seems worse after new head gasket?
Originally Posted by crx88Si
while you have the haed off, put the plugs back in, turn it upside down and fill it with oil and see if any leaks out. that will identify the valves not sealing properly.
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