LandyManLuke Posted July 24, 2009 Share Posted July 24, 2009 Evening all, Last night I got round to compression testing the 3.9 that's been sat in the project RRC for far too long unattended. I bought the car knowing that the engine wasn't running right and until now i've looked at it no more. Doing the test with cold, dry cylinders, 7 of the 8 cylinders rise to 165-175 psi within 3 or 4 revs of the engine, the 8th (no4) sits at about 60psi, which hopefully will explain the water in the exhaust the previous owner mentioned. Getting the heads off should reveal more on that front, once I get a look at the head gasket and cylinder. Before I go ahead and take the heads off, is 165-175 psi across the board for a cold dry engine acceptable or not? Are there any other tests worth doing at this stage, before the heads come off? Cheers, Luke Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted July 24, 2009 Share Posted July 24, 2009 Nope The readings you have are about right for what you have done, and you know where the culprit is ! When you take the head off look both at the head, cylinder and gasket and spark plug / combustion chamber around that area Nige Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted July 24, 2009 Author Share Posted July 24, 2009 Cheers Nige, I'm expecting/hoping to see gasket failure between the cylinder and the water jacket hole, as the adjacent cylinders tested ok and there was definitely water coming from the exhaust the last time the engine ran. Luke Quote Link to comment Share on other sites More sharing options...
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