rayaapp2 Posted October 4, 2010 Share Posted October 4, 2010 Ive been eating about a quart of oil every 3500 miles or so. I can smell it burning on decel in gear. Im almost sure its the valve stem seals. I have noticed that different oils will burn more or less than a quart during that period. Redline 5W30 lasts the longest. Royal Purple burns the fastest. Im trying Castrol full synthetic 5W30 right now. I know that the synthetic stuff tends to get consumed more than the conventional stuff. There are engines out there that are suppose to burn the oil (ie Porsche<manufacture says 2 quarts every 5000 miles> and others) and that I may not be able to prevent this, but it seams a little excessive and the smell on decel bothers me a bit. I would venture a guess that it burns enough that if there was a CAT still on the engine I would be having an issue cleaning up the HCs which Japanese emissions would have a problem with so it cant be normal. I have good compression across the board and I would think a cold test would show a problem when dry and wet tested which I do not see a change in the initial gauge needle jump. Its pretty consistent so Im leaning away from bad oil rings. The plugs show tan from the oil, but its not really obviously directional. I can only attribute this to the combustion chamber design getting the swirl evenly around the plugs and the fact that Ive pulled the plugs a few times which could adjust their position skewing my results and therefore diagnosis. The plugs are evenly tanned, but do have slightly darker spots in areas so that may point to intake valve stem seals. Also when idling after warmed up and driven for a period of time I get a light miss in the exhaust that is random. Its alot like the old fuel injected L series that end up with a lean miss-fire at idle. I wish I had an O-scope that could see the ignition system so I could pin-point the cylinder/cylinders that are missing. I have a feeling the oil consumption and miss are very related. Im not looking forward to the head job that will fix those valve stem seals if that is the problem. It would be a good chance to go with one of the nicer metal head gaskets though. IF anyone can think of something I may have missed in my diagnosis please speak up and set me straight. Quote Link to comment Share on other sites More sharing options...
mario_82_ZXT Posted October 4, 2010 Share Posted October 4, 2010 How is your PCV system plumbed? Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted October 5, 2010 Author Share Posted October 5, 2010 How is your PCV system plumbed? As stock with the exception of a catch can on the turbo inlet side. I was going to put one on the other side, but havent done that yet. BTW new PCV valve and the fixed orifice is still installed on the intake side. This morning I checked the intake manifold side and there was some oil in the hose. So I disconnected the hose from the intake and ran an air filter on both sides just to eliminate the possibility that its sucking oil through there. I went for a drive and could still smell oil on decel. Ill have to drive it farther to see if that stops. Quote Link to comment Share on other sites More sharing options...
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