73 F100 360 sudden rough and tap

Kennewick · #1 (**permalink**) 06-29-2009, 03:00 PM

Long story short I bought this 2 year sitter and after some basic clean up of the carb, replace the accel pump and check and a complete change of all the fluids, I got this thing running great at about 10 btdc. Very smooth and almost no ping. The next morning I fire it up to check the choke and it goes to fast idle starts making a knocking noise right off and running very rough. Starts right up and idles but rough and the knocking has subdued to a good tapping at rpm. Before no smoke but now a little blue white.

Thats its condition now. Facing the engine it sounds like the left side. I pull the #1 spark plug and its wet. I checked and it has spark but no change in the sound of the idle. If I pull any other wire it wants to die.

I will put a timeing light on it when I get home. Any thoughts please.

85e150six4mtod · #2 (**permalink**) 06-29-2009, 04:42 PM

Stuck lifter. You can pour detergent additive into it and hope it breaks loose. With that and the smoke, I'd start planning a rebuild.

MeanGene427 · #3 (**permalink**) 06-29-2009, 08:30 PM

Considering it sat for a couple years, a valve my have stuck in it's guide before the oil worked it's way down to lube it, pretty common with long sitters if the intake or exhaust was open to air. May have tagged a valve with the piston, and/or bent the pushrod- you'll find out when you pull the valve cover

Kennewick · #4 (**permalink**) 06-29-2009, 10:07 PM

Well facing the engine on the #1 side with the valve cover off the second valve in has a bent pushrod, as in toast. Not sure what to do next??? My guess is stuck valve alright.

Kennewick · #5 (**permalink**) 06-29-2009, 10:23 PM

So I have been driving the truck around for a few days and it has been running smooth. Any ideas on what I should do next.