The Ford Barn

Mark's 37 · 09-06-2019, 05:18 PM

My 37 221 V8 has what I think is an intermittent sticking valve. It drops a cylinder about every 4 or 5 seconds at idle. The vacuum gauge is otherwise steady but drops on the same frequency. Compression is good and uniform across all cylinders. This is a rebuilt engine with one piece guides, new valves, springs and adjustable lifters. Engine has about 4000 miles on it. Removed the intake and had a look, adjusted the valves which were not too far off. Nothing visually out of place. I think either a sticky valve/guide or a lifter hanging up intermittently. I am trying to determine which valve is the problem child. Any suggestions on how to find the offending valve?

09-06-2019, 05:18 PM	#1
Mark's 37 Senior Member Join Date: Jul 2015 Location: Aptos, Ca Posts: 355	Intermittent sticking valve My 37 221 V8 has what I think is an intermittent sticking valve. It drops a cylinder about every 4 or 5 seconds at idle. The vacuum gauge is otherwise steady but drops on the same frequency. Compression is good and uniform across all cylinders. This is a rebuilt engine with one piece guides, new valves, springs and adjustable lifters. Engine has about 4000 miles on it. Removed the intake and had a look, adjusted the valves which were not too far off. Nothing visually out of place. I think either a sticky valve/guide or a lifter hanging up intermittently. I am trying to determine which valve is the problem child. Any suggestions on how to find the offending valve?