Sticking Valve?

[Trailerman]

What started out as an intermittent tapping has now developed into an intermittent knocking.

A friend came over this evening to listen to the engine, he's used to be a diesel mechanic, so he's better as identifying good noises from bad ones. He thinks the noise is coming from the head and thought it may be a sticking valve.

He suggested I remove the valve covers and have a look to see if anything looks amiss.

He also suggested I might want to try a Seafoam treatment, he said there were pros and cons to it.

What would I be looking for if I took the valve covers off?

If it is a sticking valve what are the solutions?

[jethro]

dont put seafoam in your oil!!!!!!!!! it is not good for the heui system! put it in the fuel if you want it is ok there

[Trailerman]

I went out again this morning to listen to the knock.

The engine sounded normal at idle. Only started to knock after a short drive.

It's aloud knock, but even trying to locate it with a wooden dowel was difficult. I don't think it's coming from the top of the engine, it seems to be coming from the back, lower down.

I'm thinking big end, I hoping it's something easier to fix, ideas?

[fordmasterdieseltech]

its tough to be sure but it almost sounds like a fuel knock. you have any smoke out of the tail? you have good oil psi and fuel psi? does this noise change will engine rpm or load, louder hot or cold? thanks

[fordmasterdieseltech]

i bet if you had a way to cancel some injectors you could pinpoint that noise to 1 cylinder.

[Trailerman]

Thank you for the feedback, your thoughts are very encouraging, I really like this truck and the thought of an engine transplant or major overhaul are frightening financially, and depressing emotionally.

Yes I do have smoke from the tail pipe. It's grayish white, lots of it when it's idling cold, I smell unburnt fuel in the fumes. The smoke disappears quickly after driving for a short distance. I may get a single puff of smoke on starting after it's warm.

The increase in smoke and the noise seem to have gotten worse in conjunction with each other.

When I'm driving the truck the noise sound like a tapping, but it may be muffled out by all the other diesel noises and road noise.

I have not checked oil pressure or fuel pressure. Truth is I don't know how to do it nor do I have the gauges to do it. I have a Chilton's manual coming by mail, and I'll willing to learn how to do it.

[Trailerman]

One more fact to add.

The rpm at idle fluctuates between 645 - 725, the engine doesn't seem to stumble when driving.

A friend who supports the injector idea suggests I use an infared heat gun on the exhaust manifold for each cylinder, his suggestion is the coldest one is the bad injector.