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Injector Knock? How to fix

mattaub

New Member
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Location
hubbardston, ma
95 GMC C3500HD 6.5 Diesel

I just rebuild my turbo using a thread posted at 'the truckstop.us' titled: Rebuilding a GM8 turbo,show and tell - from user Bison.

The thread was very helpful and the turbo worked great with the rebuild kit I used.

However, you know the turbo oil return tube? Well the rubber tube that connects it to the engine split. And it was probably my fault when I was handling the return tube.

I was driving the truck and smelt oil burning, but I figured it was oil that I got on the engine. Then I saw the oil pressure start to drop. Right when the oil pressure hit zero, I shut the engine off. Looked under the truck and saw that the split in the return tube drained all the oil out of my truck.

I replaced the rubber tube that split and filled with oil. I started the truck back up and it made this horrible knocking sound. I figured I did some serious engine damage...maybe I did. But reading up on my situation and watching YouTube, I realize that maybe an injector is airlocked.

Since I drained all the oil out of the engine/oil pump/injector pump I was thinking maybe there might be some air in the line.

Any suggestions?
 
If and I do stress if it's an inj you can loosen the inj lines one at a time while the engine is running and the knock will stop when you find the one which is knocking. the loss of oil and inj knocking are not related
 
Pull the oil filter and cut it open...

30 seconds to 5 min will get all the air out of the system. put a clear return line on the IP and look for air. No air and running for 5 min should be fine. If it still knocks you dropped something in the intake or ruined something from lack of oil.

Possible a lifter collapsed and will pump back up. Or you spun a bearing and have little life left. In any case surplus engines are cheap enough and the 6.5's are crack prone. So you likely have a junk block from cracks now - no sense in trying to save anything by pulling the engine early vs. running it to diagnose it.
 
Thanks for all your help. At the moment it seems to be a spun bearing. The engine is rapping like someone is smacking a hammer against it as hard as they can. When I accelerate, the rapping gets faster. As the truck heats up, the idle starts fluttering until it stalls. I can keep it going if I keep my foot on it, though.

I'm wondering if there is enough life in it to drive it 10 miles to my house to strip some stuff off it, and then another 6 miles to a scrap yard?

Thanks again for everyone's input,

Matt
 
What shape is the truck in? Some of us are nuts enough to swap a used surplus engine and can do so for less than $2000.00. And if you looked at my truck you would wonder why I have done so - simply because it is paid for.

Post it in the classifieds and see if any members are interested.
 
Part it out.....HD is worth a few bucks.

How are the sneakers (Tires) on the truck?

Have you done any upgrades to the rig?

How's the tranny?

How many miles on the truck?........Standard or automatic trans?

What wheelbase is that HD...135.5?.....Short, Med., Long?

Truck Clean or a Banger?
 
I was thinking of parting it out, but I'm just at the point in my life where I don't want to be elbows deep in the engine anymore. I'm trying to get out of the trucking business.

The 19.5 tires are down to 20-30%, The auto tranny has never let me down, but it (and the whole truck) has 180,000 miles. I cant remember the wheelbase or CA, but when I bought it, I took off a 12' box, so I think that 96" CA

No upgrades
Just rebuilt the turbo (last week) - ran great.
bought a rebuilt starter (couple months ago) -Autozone
bought a rebuilt vac pump (couple months ago) -Autozone

Maybe I could part out as much as I can then scrap it at $165 per metric ton (today's rates). It must weigh about 6000lbs?

No compression test, But, man, it sounds BAD.

Thanks,
Matt
 
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