Guest Tim78zt Posted March 21, 2002 Share Posted March 21, 2002 What does it mean when I suddenly see a ton of blowby coming from the little open K&N vent on my valve cover? Of course this started happening after it was run real hard and also I'm off about 15 psi oil pressure. Car cruises on the freeway showing about 45 lb (half-way mark) when it used to show about 60 lb. This engine has about 18,000 miles on a megabuck teardown/rebuild. Rev-limiter on the Crane HI-6 is set at 6200rpm. Thanks in advance for any ideas!! Tim78zt Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted March 21, 2002 Share Posted March 21, 2002 My turbo motor was doing the same thing...turned out to be 2 broken ringlands on one piston and one cracked ringland on another. Do a leakdown test to see how much pressure you are leaking down and what cylinder(s) is (are) the culprit. Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted March 21, 2002 Share Posted March 21, 2002 My car did the same thing though I have you beat ZGad.... 4 broken pistons and 2 cracked. this was after an over rev/boost/mad ammouts of detonation oh well , I learned my lesson. later ~Kenny Quote Link to comment Share on other sites More sharing options...
Guest Tim78zt Posted March 21, 2002 Share Posted March 21, 2002 this does not sound good, guys. Thanks for the tip on doing the leakdown. Tim Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted March 21, 2002 Share Posted March 21, 2002 Yep Kenny, sounds like you win. Tim, atleast after the leakdown test, you'll know where you stand. How many psi were you running before it happened? Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted March 22, 2002 Share Posted March 22, 2002 yah not a good contest to win I guess oh well I am fixing it so it will be back on the road soon. good luck on the leak down test tim78zt ~Kenny Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 22, 2002 Share Posted March 22, 2002 Originally posted by Tim78zt:What does it mean when I suddenly see a ton of blowby coming from the little open K&N vent on my valve cover? Of course this started happening after it was run real hard and also I'm off about 15 psi oil pressure. Car cruises on the freeway showing about 45 lb (half-way mark) when it used to show about 60 lb. This engine has about 18,000 miles on a megabuck teardown/rebuild. Rev-limiter on the Crane HI-6 is set at 6200rpm. Thanks in advance for any ideas!! Tim78zt Blowby= blown motor. Quote Link to comment Share on other sites More sharing options...
Guest Tim78zt Posted March 22, 2002 Share Posted March 22, 2002 Z-Gad and everyone, I was running 12# boost through my DFI/ intercooled/ceramic-coated lump. Is it still safe to drive before/after the leakdown test? Is the damage already done? It seems to run fine, no extraneous noises. What is the proper procedure for a leakdown test? Cold/hot engine? How do I set up each cylinder for the test. I have a MityVac which should help. Tim Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted March 22, 2002 Share Posted March 22, 2002 well Tim, I took mine down to a buddy of mine's shop. He had the proper equipment to do the test. It only took the time to remove the plug, blow compressed air into the chamber and read the gauge in his hand. There were two gauges, one showing the amt of air entering the chamber and one showing the pressure of air which remained in the chamber. He also had me remove the crankcase breather tube to see whether the air was escaping through the crankcase. You may want to call around to a couple of local shops and see whether or not they can do it. A compression test would be the next best thing, but isn't as diffinitive. I drove mine to the shop. It ran fine for me too, but the oil pressure was a little down and just had smoke coming out from under the hood (very noticable at stop lights). Mike Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted March 22, 2002 Share Posted March 22, 2002 Oh yea, the smoke will gradually increase as you put miles on the engine... Quote Link to comment Share on other sites More sharing options...
Guest Tim78zt Posted March 22, 2002 Share Posted March 22, 2002 Yeah, Mike, the smoke at stop lights is really the embarrasing part. People look over and you can tell by the look on their face they think my engine is on fire there is so much vapor coming out of the hood vents. I asked the local Z garage about the tester and he thinks he can find the one he's used before. So I'll just take it easy (and not drive it )until I can get it over there. Tim Quote Link to comment Share on other sites More sharing options...
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