Bruce makes a good point. one other thing is that you could have a cracked
head...but not causing any noticable performance difference.

it IS possible for a head to have a ever so minute crack in a water chamber
that would cause coolent to leak (under pressure) down an oil return hole, or
pushrod hole.

One thing you could do is pull the spark plugs and examine them. if coolant IS
getting into sa cylinder, then a spark plug check can tell many tales, and show
you a cylinder you are having trouble with.

Tim



I would first look at Head Gasket, then look at cracked
head and finally cracked block. Cracked block would not happen in the
middle of the season, unless you had a Coolant FREEZE during that time
period, Cracked head, maybe, but still very unlikely for the same
reasons, except could happen if you overheated the engine recently.
Bad Head Gasket can happen anytime, and is also not to hard to deal
with, except it will require a topend disassembly, which is also
what is required for a cracked head.