1995 Sonoma

[Canadian 4X4]

I am working on my sisters sonoma 4.3L. It locked up, because of water in the drivers side back cylinder. I pulled the plugs one by one to find out which cylinder was causing it. I did a compression test and it only came up to 60PSI. I was told that some times the head is cracked between the valves, so I removed the valve cover and put a pressure tester on the coolant system and no leaks there, but the air is rushing out the back drivers side cylinder. Any Ideas as to what the issue could be? Also the Oil is milky. Probably going to pull the intake and drivers side head and change those gaskets any other ideas?
Thanks

[HAULIN IT]

The intake gasket & head gaskets are both quite common problems on the 4.3's.
It could be just the intake gasket at the rear water crossover & the coolant is running into the cylinder & outside (the air rushing).
 Spend some time to try to figure if the "rushing air" is at the seam of the intake & the head or the head to the block & go from there. If your going to pull the intake & one head...pull the other one while your at it. Get them pressure tested.
 Was it blowing White smoke out the tailpipe or how did "we" know there was a problem? If the oil has looked like Chocolate milk for a while & ran, it may be too late...bearings don't like water...much less antifreeze. Good Luck! Lorne   

[Canadian 4X4]

The truck did have white smoke and we found out about the problem when the motor locked up, My sister goes to school in Philly which is 9 hours away from us so we gotta call that the motor was locked up and she took it to a mechanic and he said he wouldn't fix it, it needs a new motor. The mechanic couldn't get it to start, I went down and got it fired up running enough to get it on the trailer. i plan to pull the intake and drivers side head tomorrow and if that head tests out good ill pull the other but if its junk, we might just find another motor, this one has 300xxx kms

[HAULIN IT]

That's what I was afraid of...doesn't sound like something you should spend much time or money on. Lorne