The engine has a skip.i have replaced the plugs
The engine has a skip.i have replaced the plugs. i had the engine scanned,and it showed the 3 and 5 cyls are where the miss is occuring.what is best guess, cap, rotor, plug wires or head gasket? engine is a 5.7 gm with 160K .
Cars & Trucks - GMC - Yukon - 1999 GMC Yukon
Answers & Comments
It is possible that the head gasket has blown between 3&5 cylinders, a leakdown test would confirm this, remove both plugs, put air to one, if you hear it leaking out the other, this is it, it should be at or close to TDC on one of the cylinders to have all valves shut for testing. Hope this helps, I know it is never good news when someone suggests you have a major engine problem,,, that is why a thorough test is allways the best plan!