Questions and Answers
Ford Tick, Tick, Tick...
Q. Ford F-250, 1995, 460 fuel injected with 88,000 miles developed what sounds like one tappet is loose and making a tick tick sound. The sound goes away if #7 plug wire is disconnected.
The sound changes in intensity as the pickup either accelerates or decelerates. The sound is minimum when coasting at any speed.
Most experts say its tappets but with the valve cover I fingered each push rod and found all tight. With engine running, applying pressure against the rocker arm caused no change.
Two experts felt it was connecting rods etc. However, the frequency of the tick tick corresponds to spark firing on #7 cylinder. Any thoughts?
Don
A. I would agree with the two mechanics that believe it is in the bottom end. A valve lifter will tick regardless of spark or not. By removing the spark from the cylinder, you are taking the load off the connecting rod bearings. So I would say the problem is with the connecting rod bearings or the piston pin.
Just for giggles, change that spark plug and wire with a new one to be 100% sure you are not hearing a spark jump.
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