6.9 idi knock

Jason hulslander1

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Hey I need some help. I picked up a 86 F250 with a 6.9 idi. And it ran really really well after a sealed the injection pump to get it running. It was fine for about 3 months then I had a freeze plug pop out in the bell housing. Got that fixed and put it all back together changed the oil. And it started knocking. Sounds like it was coming from the bottom end. At first I thought it was just an injector knock. I accidentally unplugged the cold advance solenoid and it quoted down. Did that a couple times to see if I was hearing it right.(I did). But today I went and fired it up. And it didn’t have the knock till it was idling for about a minute then it showed back up again as soon as I hit the throttle to move the truck out of my shop. Any help is appreciated. I did try cracking the lines. And I think I heard a difference when I did it to cylinder 4 and 8. But it was still faintly there.
 

Kizer

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Welcome to the forum.

Use a stethoscope (or hold a length of 3/8" hose up to your ear) to isolate the source of the knock.

Hopefully you'll find it at the injectors ... if you need new ones, go with a vendor that's recommended by the forum. The odds of getting crap injectors at the parts store, or on the interweb, are great.
 
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