MustangWorks.com : Ford Forums - View Single Post

84LX89GT · 05-18-2003, 02:52 PM

My "guess" would be that you have a possible sticking valve. If the stem of the valve gets varnish/gunk on it, it doesn't want to move freely. It can come and go with temperature, be intermittent, and this would also cause lower compression because the valve would not close all the way .It would also cause funny idle from pulses coming back in the intake or if on exhaust side causing engine to slow down trying to compress exhaust again, backfiring if it's the intake valve letting the piston push air back into intake (or exhaust). It the valve is sticking it will also cause a ticking from excessive clearances from the valve not seating fully and the rocker having to "tap" the valve.
Chances are if you figure out what's going on with cylinder 8, it will solve the problem, just a guess though

05-18-2003, 02:52 PM	#2
84LX89GT Mustangs Join Date: Jul 2000 Posts: 1,938	My "guess" would be that you have a possible sticking valve. If the stem of the valve gets varnish/gunk on it, it doesn't want to move freely. It can come and go with temperature, be intermittent, and this would also cause lower compression because the valve would not close all the way .It would also cause funny idle from pulses coming back in the intake or if on exhaust side causing engine to slow down trying to compress exhaust again, backfiring if it's the intake valve letting the piston push air back into intake (or exhaust). It the valve is sticking it will also cause a ticking from excessive clearances from the valve not seating fully and the rocker having to "tap" the valve. Chances are if you figure out what's going on with cylinder 8, it will solve the problem, just a guess though __________________ 2005 Suzuki Hayabusa GSX1300-R 1980 Ford Thunderbird - 255 V8 ported heads, 5.0L ported stock headers, O.R. H-pipe and Flowmaster 2-chambers, dual roller timing chain hi-po Mack Truck hood emblem 1985 Mustang GT 5.0L T5, F-303, GT40p, headers, off-road h, flowmasters, MSD stuff, etc. Sold 02/06/04 1989 Mustang GT ET: 13.304@102.29 mph (5-24-03) Sold - 1998 Mustang Cobra coupe, 1/4 mile - street tires: 13.843@103.41 (bone stock)