How do you know if you lifted a head?

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Apr 4, 2003 | 06:47 PM

jrios

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From: san jose, ca

How do you know if you lifted a head?

Just curious what symptoms have you seen that tells you the heads lifted? Maybe coolant in oil or blow by.

Thanks

Apr 5, 2003 | 06:20 AM

SS00Blue

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Re: How do you know if you lifted a head?

<blockquote>quote:<hr />Originally posted by jrios:
 Just curious what symptoms have you seen that tells you the heads lifted? Maybe coolant in oil or blow by.

Thanks <hr /></blockquote>You can do a coolant system pressure test. Leak down test. Or you can just apply 100PSI of compressed air to each cylinder with the valves seated, and the air will pressurize your coolant system, or you will hear it escaping through the dipstick tube.

In addition to the two symptoms you listed, you may find that coolant is overflowing your catch bottle, white smoke from tailpipes.

A few FI LS1 owners have reported that their heads weep coolant from the head-to-block mating surface. This would be interesting because I don't know of any other engine design that shows a blown head gasket in this way.

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Apr 5, 2003 | 09:41 AM

NoOne

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From: Green Oak, MI

Re: How do you know if you lifted a head?

You may not have blown a headgasket if you have this problem.

I just finished taking the heads off, thinking I blew a head gasket to find out I did not. I simply stretched the bolts enough(stock GM) to the point where they did not seal well enough.

My passenger side bolts were tight and sealed fine, my driver side towards the back where looser and the 2nd from the last center 16mm bolt didn't even take a breaker bar to get loose.

If head studs can be done in the car, without removing the heads and changing the gasket I would say do it, it'll save yourself trouble later.

Apr 8, 2003 | 12:02 AM

jrios

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From: san jose, ca

Re: How do you know if you lifted a head?

I did a compression test and my compression ranged from 185 to 190. I did a leak down test and it ranges from 5% to 15%. Only one cylinder was at 5% the rest were 10% to 15%. I am definitely getting blow by and I am getting condensation on the bottom of my oil cap. The motor has about 2,500 miles on it. Could this still be a lifted head?

Apr 8, 2003 | 07:04 AM

SS00Blue

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Re: How do you know if you lifted a head?

<blockquote>quote:<hr />Originally posted by jrios:
 I did a compression test and my compression ranged from 185 to 190. I did a leak down test and it ranges from 5% to 15%. Only one cylinder was at 5% the rest were 10% to 15%. I am definitely getting blow by and I am getting condensation on the bottom of my oil cap. The motor has about 2,500 miles on it. Could this still be a lifted head? <hr /></blockquote>A 2500 mile motor, and you're seeing 10-15%? Wow!

Anyway, My motor runs perfectly and I've seen condensation on the bottom of the oil cap. That doesn't necessarily indicate a problem. Do the coolant system pressure test. If it loses pressure, you're ventilated.

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Apr 8, 2003 | 10:28 AM

jrios

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From: san jose, ca

Re: How do you know if you lifted a head?

Okay. I'll do the coolant check.

My others thoughts were that maybe the rings didn't seat. I am using chrome moly rings and I heard that it is hard to get them to seat.

Apr 8, 2003 | 11:12 AM

SS00Blue

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Re: How do you know if you lifted a head?

<blockquote>quote:<hr />Originally posted by jrios:
 Okay. I'll do the coolant check.

My others thoughts were that maybe the rings didn't seat. I am using chrome moly rings and I heard that it is hard to get them to seat. <hr /></blockquote>That explains the leakdown.