Engine knock after glow plug replacement.

[cheddarbob03]

I'm new to the forum but have used for reference a lot. There's a bunch of good people with good info on here so thanks. Which is why I'm hoping someone can point me in the right direction

So a rundown of my issue and engine history.

I've got a 93 f250 that was a factory idit that blew. I swapped in a 92 7.3 idi n/a engine. It's been running great. I've been driving it 40+ miles a day for the last 8 months. Has a couple leaks that I've fixed. It's had a slight tick that I wasn't really sure if it was "diesel knock" or an actual problem. Fast forward to this weekend.....

I replaced the glow plugs. They all came out easy and intact. They didn't look too bad. No mushrooming burns etc. I put the new ones in and it fired right up. Sounded fine. Shut it off and let set the weekend. Fired it up Sunday evening and sounded great until I went past 1000-1100 rpm. It sounds like a bad rod knock but that doesn't make sense.

Any thoughts or opinions would be greatly appreciated.

 

[Waystro]

Get a video that'll help us.

 

[icanfixall]

Welcome to the forum. Can you tell us how many miles are on the injectors? Sounds to me like an injector knock. Also did you remove any injector hard lines for easier accesss to the glow plugs? Its generally felt here if an injector or injection pump has 125,000 miles on them they are worn out. some get more miles and some get less but 125 is the time they start showing wear.

 

[79jasper]

Disturbed a return cap.

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[FORDF250HDXLT]

Disturbed a return cap.

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would cause engine to knock?

 

[79jasper]

Constant, no.
But on startup it could.

If all the glowplugs looked fine, shouldn't be any tips banging around or anything.

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[cheddarbob03]

https://youtu.be/GnDlBLFajO4

Here is the video. The audio doesn't really do it justice but you can hear the knock near the end.


Thanks for the input guys.

Oh and to the best of my knowledge the injectors and ip are original, which is about 180,000 miles. I know, I know. Theyre overdue. I was going to replace them in the next couple months, but it looks like that might be sooner than planned......

 

[OLDBULL8]

Pull the air cleaner off, see what it sounds like then. Sounds to me like a phsst phsst phsst.

 

[cheddarbob03]

Also, no injector lines were removed. And the knock is worse after warmup than it is cold.

 

[riotwarrior]

All gp same length when removed correct?

Ya pull air cleaner lid.

Also feel injector lines by injectors is one way warmer than others?

It almost sou.ds valve train related however still need more info.

 

[OLDBULL8]

It almost sou.ds valve train related however still need more info.

That's what I'm thinking Al.

 

[cheddarbob03]

Hmmm. I'll have to dig into it later in the weekend. I'll pull the valve covers and see if anything shows its ugly face.

 

[FORDF250HDXLT]

to me that's a "tick" not a "knock". it has that collapsed lifter sound to it.

 

[blakken]

Did you found the problem?
Mine sound like that.

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[cheddarbob03]

Sooo on further investigation nothing obvious. Valve stem heights look the same. Pushrods, lifters, rockers also normal. And the video really doesn't do the sound justice. It's a fair bit louder. At this point I'm considering pulling it and doing bearings rather than throwing a bunch of money into injectors and ip to find it still making noise.