Bent Valve or ??
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Bent Valve or ??
1991 F-250, with EFI 302. Been a while since I had to tear down a ford, but, here is what is going on. Slight stumble in the motor, no water and oil mixing, no backfiring. All spark plugs look ok, no major oil deposits on them. Did a compression test on the drivers side today. First 3 cylinders came in between 170-175. Last cylinder, is 0, checked it 3 times. Previous owner had little to no oil in the motor, when I got it. And again, no oil and water mixing. I am leaning towards a bent valve, that is stuck open, thus no compression. I will pull the valve cover tomorrow, and check that out. But, does anyone more knowledgeable on these motors have any idea? If needed I will rebuild it, but, for now was wondering if I am guessing correctly, missing something, or is there a quick fix, until I pull and rebuild the motor?
Thanks
Thanks
Lead Driver
Joined: May 2011
Posts: 5,772
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You don't need fancy equipment, rig up an adapter to the plug of that cylinder to your air hose. Make sure the valves are closed, and let the air rip. You'll be able to hear where it goes, whether it's the exhaust, intake, or crank case.
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