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Engineering/Technical Ask technical questions about cars. Do you know how a car engine works? |
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02-26-2010, 08:50 AM | #1 | |
AF Newbie
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Leak Down Test
when performing a leak down test how will you be able to tell if you have a cracked head or blown head gasket?
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02-26-2010, 10:32 AM | #2 | |
The RustBuster
Join Date: Feb 2006
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Re: Leak Down Test
You should hear/feel the air coming out of the adjacent cylinder's spark plug hole.
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02-26-2010, 10:07 PM | #3 | |
Nothing scares me anymore
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Re: Leak Down Test
It all depends on how it's blown, and/or cracked. Often, you will get the cooling system start to pressurize (the rad hose gets firm, or if the rad cap is off, bubbles come out. )
Sometimes a blown HG will leak to an adjacent cylinder or to the crankcase. Sometimes a head that's cracked around a valve seat will push air past an intake or exhaust valve (although this is more indicitive os a burned/leaking valve). So, generally, you can confirm a blown HG or cracked head in this manner. But an absence of such symptoms does not exclude the possibility of a problem. |
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03-03-2010, 02:50 PM | #4 | |
AF Enthusiast
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Re: Leak Down Test
A good 100psi on each cylinder under test should be good!
see www.youtube.com/watch?v=jG_RWs8ckp4 |
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