DesertLake
SILVER Star
1FZ troubles...
I rebuilt this motor about 30,000 miles ago, no problems until the last year or so.
Douglas Machine built the head for me, so I don't have the direct experience with valve assembly.
Earlier this year I lost compression in at least two cylinders, so I pulled the valve cover and discovered I had 0 clearance on a few intake valves.
Re-shimmed, and my compression was 150 to 160 on every cylinder.
Not long ago it sounded like I had lost compression again, and sure enough #1 is only at about 90 lbs. Pulled the valve cover tonight and found #1 rear intake valve went from .229mm clearance to 0mm in about 6000 miles. This was one of the ones I already adjusted due to lost clearance.
I haven't measured the others yet.
Sounds like the valve seat is wearing or moving, I think? How/why does this happen?
I rebuilt this motor about 30,000 miles ago, no problems until the last year or so.
Douglas Machine built the head for me, so I don't have the direct experience with valve assembly.
Earlier this year I lost compression in at least two cylinders, so I pulled the valve cover and discovered I had 0 clearance on a few intake valves.
Re-shimmed, and my compression was 150 to 160 on every cylinder.
Not long ago it sounded like I had lost compression again, and sure enough #1 is only at about 90 lbs. Pulled the valve cover tonight and found #1 rear intake valve went from .229mm clearance to 0mm in about 6000 miles. This was one of the ones I already adjusted due to lost clearance.
I haven't measured the others yet.
Sounds like the valve seat is wearing or moving, I think? How/why does this happen?