head gasket

[92tsiawdguy]

the other day i was going to go out and drive the talon well i checked the cooling system cause everything is still very new and i saw a drop of oil in the coolant so i drained it and it was only a drop or to in the bucket. So i figured blown head gasket. i checked the compression and i have from left to right 117 115 115 120. i have a hks head gasket and arp head studs. im wondering if i boosted too much for the gasket. should i retorque the studs? Still runs good and doesnt smoke. Just wanting to know what i should do.

 

[Detective Coating]

Did you check your compression before you added the studs and new HG? Have you done a wet compression test?

 

[Whophlungpoo]

Those compression test results seem fine for me. How is your coolant level after a couple nice pulls? And what does your oil look like?

 

[Detective Coating]

Those compression test results seem fine for me. How is your coolant level after a couple nice pulls? And what does your oil look like?

Are you serious? Those numbers are awful! It is suppose to be 164psi and service limit is 121psi. Quite obviously he is in the service limit area and needs to figure out what is wrong with the engine.

 

[Whophlungpoo]

Are you serious? Those numbers are awful! It is suppose to be 164psi and service limit is 121psi. Quite obviously he is in the service limit area and needs to figure out what is wrong with the engine.

Yes the numbers are low, but they are consistently low something a blown head gasket is not really symptom of these results. Sometimes the tester registers high or lower then what is actual.

 

[1992awdlaser]

Yes the numbers are low, but they are consistently low something a blown head gasket is not really symptom of these results.

Agreed

Have you done a wet compression test?

I don't kow how many times I have to say this:

Putting oil in the cylinders will ALWAYS make the compression go up. The oil will sit in the dish of the piston which causes less space for the air to occupy when the piston moves upward. That of course means the compression will go up.

The only easy way to know what is wrong is to do a leakdown test.

 

[Whophlungpoo]

I also sell quite a bit of these:


Detail Page for 75500 Combustion Leak Detector - Lisle Corporation


I haven't had the chance to use one of these yet though.

 

[92tsiawdguy]

well when i first got the engine it made 135-140 all the way across, but i havent checked it since i got it. I just put some 264 272 hks cams in it so i was wondering if thats changing anything. he engine has 40xxx miles and the head and gasket/studs have 5xxx miles on them. it doesnt seem to lose coolant and it runs great and stays cool.

 

[kris_stewart10]

well then if it isnt broke dont fix it

 

[92tsiawdguy]

im just wondering why i would have oil in the coolant

 

[dSmgs-T]

try a leak down test and come back with those results.

 

[j92eagle]

If you torgue the head bolts and then torque them down again would that not make the head bolts junk ### you can only use head bolts like once or would that not hurt it?

 

[schroder]

Flame me if I am wrong, but I belive ARPs can be torqued 2x before its recommeded to replace them...

 

[92tsiawdguy]

they can be reused. I talked to the owner of a shop and he told me because of the overlap in the new cams it will lower the compression. The slower its turned the less pressure you will get because of the over lap.

 

[Boost92awd]

Dont forget to do a running compression test. Remember the compression pressure of a running engine is much lower than a cranking compression test. The engine is revolving faster, and therefore, there is less time for air to enter the combustion chamber. With less air to compress, the compression pressure is lower. Typically, the higher the engine RPM, the lower the running compression.

Your looking for 60-90 PSI. The running compression of all cylinder should be equal. Broken valve springs, worn valve guides, and worn cam lobes are some items that would be indicated by a low running compression test reading on one or more cylinders.