HELP)!!! Compression Numbers
Aug 28, 2007, 06:59 PM
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HELP)!!! Compression Numbers
Ok here is what I got for compression numbers, the reason why I did the test is because I got owned by my friends 06 sti stage 2, and I have the following mods in my sig. So here are the numbers.
cylinder 1) 152
2) 152
3) 130
4) 152
Now this is a real cheap gauges, so I believe that is why I am in the 150's, when my friend who is a tech used it gauge it was reading 1) 175, 2) 175, 3)152, 4)175... that was taken months ago.. before we did the head gasket and new arp head studs.. So after the new gasket and head studs, I am still loosing compression in number 3. Also if you add oil to the cylinder it does not go up in readings, and a leaking down test was performed before the head gasket was replaced to rule out a hurt motor, and it was only a 4% loss...
SO fellas can you help me out on what to do next?
cylinder 1) 152
2) 152
3) 130
4) 152
Now this is a real cheap gauges, so I believe that is why I am in the 150's, when my friend who is a tech used it gauge it was reading 1) 175, 2) 175, 3)152, 4)175... that was taken months ago.. before we did the head gasket and new arp head studs.. So after the new gasket and head studs, I am still loosing compression in number 3. Also if you add oil to the cylinder it does not go up in readings, and a leaking down test was performed before the head gasket was replaced to rule out a hurt motor, and it was only a 4% loss...
SO fellas can you help me out on what to do next?
Aug 28, 2007, 08:17 PM
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We did the compression test 3 times same cylinder to make sure the test was accurate.
I have already did a leak down test, couldnt find a leak only 4% loss in air.
Yea I was making 310 on a mustang at 22 psi..
I have already did a leak down test, couldnt find a leak only 4% loss in air.
Yea I was making 310 on a mustang at 22 psi..
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Aug 28, 2007, 08:40 PM
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I never heard of this and since your rings checked good, I guess you could adapt a fitting to the #3 plug and apply a little air with the cylinder positioned on compression stroke. Loosen the manifold to see if it's the exhaust valve, figure a way to check for leaks at the intake valve, if neither then the head has to come off .
At least it's a good thing you caught it early
At least it's a good thing you caught it early
Aug 28, 2007, 08:47 PM
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the head was already off the car about 1 month a go... valves looked fine and sealed... only conclusion I have came up with is the LIFTERS in cylinder 3 are no good.
