Bent valves maybe??

[festivaWES]

Stuck valves can happen, that fast after a oil change and a trip...i don't know. People go on trips all the time and leave their engines sit long periods of time.

At work we take the spark plugs out and jam rope into the cylinder till no more will go in. Hand crank the bolt on the crank pulley until itc in compression stroke to smash the rope into the valve and break it free.

[ventura_ace]

If your valves were stuck open you would not have gotten anywhere near the compression #'s you say you got.

Yes, I thought the same, so I am still perplexed about the whole thing. Perhaps the valves were stuck open just a tiny bit, enough to let the compression show a low reading -- but I would have thought the car would run to some extent if it was getting that much compression. Maybe I have a problem with my compression gauge.

It sure runs good now. I'm tempted to let it sit for a couple weeks and see if the mystery repeats itself. I guess I would need to replace the oil filter again, if I really want to retest the theory.

A

[Sandm849]

yea valves don't close=no compression