Quick Head Gasket Leak Test

DOC4444 · **Posted:** Mon Sep 23, 2013 7:14 am

Racertracer has been advocating a quick test for our head haskets for a while, now. I am not aware of loosing coolant, but it would seem to me to make sense for everyone to do this periodically. It involves starting after sitting overnight, running for 30 seconds, shutting off and removing the cap from the header tank. The idea is that if there has already been any pressure buildup in this short time, you have a leak.

I would like to propose that everyone do this and post their findings, noting whether they are experiencing coolant loss or not and, if so, how much.

It would be good to know if anyone loosing coolant does not observe this quick pressure buildup and, conversely, if anyone who is not, does see it.

(I tried it twice and did not observe any pressure buildup.)

DOC

Hexus · **Posted:** Mon Sep 23, 2013 10:58 am

I've tried it a few times, tried it again today, no pressure build up at all.

thermorex · **Posted:** Mon Sep 23, 2013 2:34 pm

Tried it few weeks ago, no buildup, 126k on board.

Smacker · **Posted:** Mon Sep 23, 2013 2:41 pm

Have tried this test a few times. Before and after installing the ARP head studs. No pressure build-up. Jeep runs better than ever, but still losing coolant somwhere. Trying to rule out everything I can before pulling the head and looking for cracks.

user113 · **Posted:** Mon Sep 23, 2013 11:09 pm

Have you tried the fluorescent dye?

Hexus · **Posted:** Tue Sep 24, 2013 9:23 am

Smacker wrote:

Have tried this test a few times. Before and after installing the ARP head studs. No pressure build-up. Jeep runs better than ever, but still losing coolant somwhere. Trying to rule out everything I can before pulling the head and looking for cracks.

Look very closely on the EGR side of your engine, especially at the connections and tees.

pwrwagn · **Joined:** Mon Jul 22, 2013 2:40 am **Posts:** 192

DOC4444 wrote:

Racertracer has been advocating a quick test for our head haskets for a while, now. I am not aware of loosing coolant, but it would seem to me to make sense for everyone to do this periodically. It involves starting after sitting overnight, running for 30 seconds, shutting off and removing the cap from the header tank. The idea is that if there has already been any pressure buildup in this short time, you have a leak.

I would like to propose that everyone do this and post their findings, noting whether they are experiencing coolant loss or not and, if so, how much.

It would be good to know if anyone loosing coolant does not observe this quick pressure buildup and, conversely, if anyone who is not, does see it.

(I tried it twice and did not observe any pressure buildup.)

DOC

My CRD had an obvious head gasket leak, and this test showed nothing.

It actually had to idle for several minutes before the first bubble showed up. It basically didn't leak any signficant amount until you put the motor under load. HOWEVER, when you shut it off hot, with pressure in the coolant system, it forced coolant into the cylinder.

Not impugning the test, BTW, just warning that it is NOT infallible. Your "infallible" test is very old fashioned, which tests for CO2 building up in the coolant.

LMWatBullRun · **Posted:** Wed Sep 25, 2013 7:56 am

Smacker wrote:

Have tried this test a few times. Before and after installing the ARP head studs. No pressure build-up. Jeep runs better than ever, but still losing coolant somwhere. Trying to rule out everything I can before pulling the head and looking for cracks.

If I were you and I had used dye and checked the EGR, the WP etc. and had found no leaks, before I pulled the head I would remove the injectors and stick a fiber optic camera down the injector hole and look to see what each cylinder looked like. If you have coolant getting into one cylinder, you will see a notable difference in the appearance of the top of the piston. Whether or not this can be detected on camera I do not know but I would try that first.

Hope that helps!

Smacker · **Posted:** Wed Sep 25, 2013 11:05 am

Inserting the dye this morning and will check after I run some errands.

Quick Head Gasket Leak Test

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