Engine knocking for came and went away in a minute

[Clay46]

I just put a new injection pump in and timed it, took it on a test drive and on the way back while I was coasting down a hill in 3rd gear I got a horrible engine knock for about a minute then went away mostly. I can still somewhat hear a knock at idle when I'm not in the truck, sounds like one of the rear 2 cylinders on the passenger side. I timed the pump to 9.5 degrees and it seemed pretty happy there. Just wondering if there is something other than internal engine components that could cause this knock, im fairly new to diesels. Though some research I think it might be an injector might have gotten some dirt in it but would like a second opinion. It sounded like a really loud hollow knock. Truck is a 84 f250 with a 6.9

 

[riphip]

Have you changed glowplugs lately? May have one with a broken (off) tip.

 

[Clay46]

Have you changed glowplugs lately?

I replaced glowplugs and injectors roughly 4 months ago

 

[Kevin 007]

Also a sticking lifter can do this. they will hold a valve open a little bit and it will sound like a knock. Lifter noises like that often come and go. USUALY after start up however.

 

[Clay46]

Also a sticking lifter can do this. they will hold a valve open a little bit and it will sound like a knock. Lifter noises like that often come and go. USUALY after start up however.

I just went out this morning and started it up and I had no noise. The engine only has 59k miles on it and I just had the valve covers off and it was really clean under there so I don't think it would be a lifter but it's not off the table. I'll try to listen for it again. It was loud, I thought it was rod knock before I did a little research before I got home. It seems to run ok now. I think I hear it but it's very quiet and goes away right off idle but it might just me being paranoid and it might have always had a little bit of a clack at idle

 

[Laine D]

What brand pump did you put on it?
My Delphi reman had a really mean fuel knock and I ended up having to replace it. Was really bad.

 

[Clay46]

What brand pump did you put on it?
My Delphi reman had a really mean fuel knock and I ended up having to replace it. Was really bad.

It's a baby moose pump from Conestoga diesel so I'd hope the pump isn't the issue but since it went away I don't believe it's a pump issue but I could be wrong

 

[Laine D]

It's a baby moose pump from Conestoga diesel so I'd hope the pump isn't the issue but since it went away I don't believe it's a pump issue but I could be wrong

Oh good. That is a reputable place so no worries there