Paul is an extremely experienced mechanic when it comes to these Toyota RV V-6 engines.
Experienced with the 4 cyl, but less so with the V6 as I haven’t ever
owned one.
From what I gather, it is more important that the compression be close
to the same on all of them, rather than the actual numbers. If one is
very low (most commonly #6) that's when an adjustment is needed,
before any of them burn. Paul, did I get it right?
More or less true. In other words, if a cylinder compression check
reveals the compression is high on all 6 cylinders (over about 160+ PSI )
then the owner can skip the more expensive valve clearance
check, but should still consider having the compression checked again
about every 25,000 miles thereafter.
But if compression is under about 150 PSI on some cylinders then
the owner knows the exhaust valve clearances on those cylinders
have become too tight and their clearances should be adjusted
(loosened) soon to prevent severe valve burning and permanent
total loss of compression.
Paul Cherubini
