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Engine won't run (missing cylinder) at end of street after pulling out of garage - was showing cold on recently replaced temp. gauge, but had just driven it a few hours ago no problems - pulled the spark plugs - 1&2 ok but dark with soot, 3 bent partly closed, 4 completely shut. Looking down at the pistons, 1,2 look normal, 3 I can see the hit marks from the plug, 4 is black (sooty and slightly oily - probably from not firing) and I can see marks on the top also.
Pulled the valve cover and the timing chain looks perfect and taut - cams look perfect also.
Turned engine over with torque wrench - easily goes with 4 distinct compression cycles, easy to turn (I haven't turned over a turbo like this so probably why it feels fairly easy - 1/2 torque wrench used) - can't see anything unusual when turning over except when the pistons top out (described above) -
Engine will idle with gas - rpms fluctuate and rattle is heard (piston hitting plug?)
Only other time something like this is 63 corvair turbo that kept shutting the plugs - then the rings blew out and tore up the chambers, but that was some pretty serious detonation -
Only thing strange was some hesitation lately when under light boost at low rpms like it was misfiring last week - would go away with rpms or less boost - ran it to redline once that week and it ran perfectly.
ALSO - oil looks perfect - no sludge seen, smells ok, galleys where the cams are both filled with oil - can see lifters when you turn engine over but not when the cams is pushing them -
Magnetic plug on bottom but haven't drained - no metal on stick or anywhere I can see - should I pull the pan off? Or is pulling the head the only way to check the pistons (or easier) -
There's quite a few experts here so let's see if anything obvious before I take more off and take pics...
posted by 64.216.4...
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