Quote:
Originally Posted by Laird Scooby
Have you tried the teaspoon of oil down the plug hole of #3 to see if the compression came up at all?
Might be worth investing in a cheap boroscope (usually abut a tenner, plug into a laptop/tablet/phone) to poke into the plug hole and see if there's anything obviously out of place.
Not sure i understand what you've said about the valve clearances, i can see the correlation but the larger clearances correspond to the higher compression which is what i would expect.
Would i be right in assuming that all plugs were out for the test and only the tester was screwed in to the relevant plug hole for each test? 
Nearly forgot - did you remove the hushers before checking the valve clearances? As many will tell you on here, they can cause false clearances to be ecorded if left in place. |
The hushers don't last long so on an 80k mile engine they will be completely disintegrated and have no effect on the shim gaps, plus you would have to remove the camshaft to remove them.