exhaust valve troubles 91 3.0 vze
#1
exhaust valve troubles 91 3.0 vze
Hello all,
This thread is a result of many helpful tips from members more experienced with this motor and motors in general, than I. I decided to start a seperate thread to focus on the last remaining issue. I have a problem with compression in cylinder 3 of my 3.vze. the #3 cylinder is at 30-40 psi and the others are within spec 140-160
After pulling all the stuff out to get to the valve cover, I got in there with my feeler gauges, 5 of the six valves are right within tolerance, but the exhaust valve on cylinder #3 has zero clearance. I cant even get my slimmest gauge in there. I have been sure to measure on the base circle with the lobe pointing up. could it be that this valve just needs a smaller puck? and my plan of pulling the heads could be scrapped?
This thread is a result of many helpful tips from members more experienced with this motor and motors in general, than I. I decided to start a seperate thread to focus on the last remaining issue. I have a problem with compression in cylinder 3 of my 3.vze. the #3 cylinder is at 30-40 psi and the others are within spec 140-160
After pulling all the stuff out to get to the valve cover, I got in there with my feeler gauges, 5 of the six valves are right within tolerance, but the exhaust valve on cylinder #3 has zero clearance. I cant even get my slimmest gauge in there. I have been sure to measure on the base circle with the lobe pointing up. could it be that this valve just needs a smaller puck? and my plan of pulling the heads could be scrapped?
#2
Registered User
Almost certainly..... No.
The valve has burned long since the clearance diminished to nothing.
Restoring the lash by re-shimming that valve might give slightly more compression, but likely not.
If you expect good continued service from your engine, that head has to come off.
Depending on what you see with the head gaskets general condition on disassembly, you probably should service the other head as well.
All exhaust lash clearances should be restored to their maximum.
The intakes are not quite so picky, as they run much cooler, and don't close up as fast.
You should probably service, or replace the injectors while you're in there.
Sometimes a sub-standard injector, spraying lean is what made the bad exhaust valve run hot in the first place.
The valve has burned long since the clearance diminished to nothing.
Restoring the lash by re-shimming that valve might give slightly more compression, but likely not.
If you expect good continued service from your engine, that head has to come off.
Depending on what you see with the head gaskets general condition on disassembly, you probably should service the other head as well.
All exhaust lash clearances should be restored to their maximum.
The intakes are not quite so picky, as they run much cooler, and don't close up as fast.
You should probably service, or replace the injectors while you're in there.
Sometimes a sub-standard injector, spraying lean is what made the bad exhaust valve run hot in the first place.
Last edited by millball; 07-10-2016 at 10:19 PM.
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