I have an 07 cobalt that the number 4 cylinder will not fire. After new plug, and different coil, I discovered only 50 PSI compression in that cylinder. I have removed intake, exhaust and am ready to remove the head to see if it is a bad valve or bad head gasket but I can't figure out how to loosen the timing chain to get the two cam sprockets off and be able to lift the head off.
Please help...Mooseman
Please help...Mooseman