88 m20b25 in my 87, 99,000 miles or so.
Before I installed the new motor, I replaced all the seals, gaskets, yada,yada. Lots of noise from the head so I pulled it and sent it to a machine shop. New valve seats, guides and seals, reground valves, pressure check, re-install.
The noise is gone at idle, but comes back around 1500 rpm. If you slowly rev it up, you can hear it start - hhhuuummmmmtinkhhhuummmmtink till it becomes a steady tickticktick, maybe from one or two valves. It also seems to be affected by engine load. Under acceleration, it if fairly quiet, lift off the gas and it gets a lot louder.
I've done numerous valve adjustments at .010 and even tried .008 with no change.
Any suggestions?
Keith
Before I installed the new motor, I replaced all the seals, gaskets, yada,yada. Lots of noise from the head so I pulled it and sent it to a machine shop. New valve seats, guides and seals, reground valves, pressure check, re-install.
The noise is gone at idle, but comes back around 1500 rpm. If you slowly rev it up, you can hear it start - hhhuuummmmmtinkhhhuummmmtink till it becomes a steady tickticktick, maybe from one or two valves. It also seems to be affected by engine load. Under acceleration, it if fairly quiet, lift off the gas and it gets a lot louder.
I've done numerous valve adjustments at .010 and even tried .008 with no change.
Any suggestions?
Keith
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