Issues with s50

[Am pM HooDluM]

I'm having some issues with the way my car is running. Basically it ran perfectly fine till I drove it today. I got on a little bit today took it no higher than 6k when getting on it. Car didn't have the O2 hooked up yet, when I got off the freeway the car would basically just die. Check all the fluids they were all good. Reset the ECU (remove power for a few min then hooked back up) Car would start and idle rough around 400-500rpm. Some loss of power at low end, top end is still good.

Run a compression test on it 180-130-0-190-0-0. Weird thing is that we couldn't get any compression on cylinders 3, 5, and 6. Which doesn't make any sense, there is no smoke or anything coming from exhaust. Plugs look all good not in fuel or oil coated at all. Got the O2 hooked up, didn't make a difference, thinking the fuel map was just dumping fuel. Took the valve cover off and everything looked good.

FYI, no money shift or coolant in oil ;)

Any ideas on what could be checked next?

[static]

well, the next step should be leakdown to determine where the compression goes in those cylinders (i.e where it leaks out)
perhaps you blew the gasket

when/if you open the engine , don't forget to change retainers for newer style

good luck

[matt]

Sounds like a head gasket... or bent valves.

[e30pwr]

How old was the motor when you got it and what rebuild if any? Could be compression rings but with 3 cylinders going out that fast I'd say head gasket.

[Am pM HooDluM]

Thanks guys. The next idea I had was to pull the head. I'll do the leak down test, and go from there. Just wanted some outside opinions. ::thumbsup::