Questions and Answers

Ford F-250 Engine Ticking Q. Hi Vince, You helped me concerning new Cylinder Heads for my 1990 Ford F-250, Thank You. Now I have another problem. The Heads are done. (I put in two, brand new cast, OEM heads) While I was at it, I also replaced the exhaust manifolds, cleaned out the intake manifold and all other parts that were removed or accessible.

I performed a tune up, replacing the distributor cap, rotor, plugs, plug wires, PCV valve, air filter, fuel filter, and breather filter. When the heads were done the distributor was removed so the timing has also been set.

Here's the problem, I get a ticking sound from the engine, as the RPM's increase so does the ticking, it's not too loud but it is aggravating. It seems to be coming from the drivers side of the engine. Also, the idle isn't as smooth as it should be after all that has been done. It drops slightly periodically (drops about 100 -200 rpm) but isn't consistent, there isn't a set pattern that it drops, and the truck never stalls.

When I drive, it seems to run very smooth and responds very well when I accelerate. I thought maybe one of the valves from the head wasn't seated properly so maybe one of the cylinders wasn't firing. I removed the plug wires from the distributor cap one at a time. Each time I removed a plug wire there was a change in the idle so I know that all the cylinders are firing.

Could it be a clogged fuel injector or be due to the new heads needing to be broken in a little? I haven't changed the oil yet since the heads were done, I wanted to drive the truck for a couple hundred miles to flush out any debris or shavings from the head job before I changed it. Not that I saw any excessive shavings or debris while doing the heads, it all went very smooth.

The last oil change was done under 1000 miles ago and the oil looks good (not burnt or gummed up) The truck is a 1990 Ford F-250 XLT Lariat with a 7.5 Liter 460 Fuel injected engine. it has 93,000 miles on it. Any direction you can point me in towards debug would be greatly appreciated.

Thank You,
Ed

A. I would suggest changing the oil and filter now. I always change the oil and filter when I'm done with a head job and before I start it.

Then I would drive it for 1,000 miles or so to give the valves a chance to fully seat. Then you should adjust the valves and that should get rid of the ticking noise. I would also recommend changing the oil and filter again and then every 3,000 miles after that.

Sounds like you did a good job with it. Bet it feels nice driving down the road.