0 Compression?

[FD.Fred]

Ok, so here's the deal. My car started misfiring like crazy after a little run down the highway. I figured I'd do a compression test. Cylinders 1 to 3 are tip-top, cylinder four though as 0 compression. Where should I go from there? What are the possible issues? Bent exhaust or intake valve, broken head gasket, damaged rocker arm... Anybody ran into some similar issue? Ill take any advice I can! My next step would be a leak test. Thanks guys!

[stealthsr20]

ti could be a number of things, leak down and see!

[essforteen]

Did the car overheat?
It could be a broken ring land!
Or bent valves or as small as a had gasket!
GL. Leak down test will help determine if valves are good!!

[rhd_sw20]

over rev?
had the exact same problems. #4 rocker arm came off.

[fliprayzin240sx]

sounds like a broken ring land or a hole in the piston.

[handinpants]

I would say leak down, open up your radiator cap and oil cap, and listen, listen forthat air noise from exhaust, or from oil cap, listen for air in intake, and watch for bubble in coolant.

[TheWolf]

leakdown and listen with a mechanics stehiscope. Probably either a bent valve or a hole in piston. Blown headgaskets and broken ringlands usually result in some compresson. 10psi or so. You'll find the air is blowing up the intake (intake valve) out the exhaust port (exhaust valve) or remove the dipstick (better than oil fill cap) and it will be blowing through the hole in the piston.

[FD.Fred]

thanks guys, ill look it up and keep u posted!