Engine Knock and Charcoal Turbo

[Mbl35]

Started checking an 03 e350 for a engine knock, it seems to be from the drivers side front area. Im going to pull valve cover

and unplug 1 inj. at a time to see which cyl it is. Anyone ever change an injector for a knock? It runs good and buzz test passes. I only changed 2 7.3 inj. and it was for dead misfires.

Also the turbo seems to be leaking in the middle somewhere and the top of the aluminum housing of the turbo is like charcoal when it starts cooling off on the barbeque, its black, grey and ashy with little chunks rubing off when you touch it. It seems like the turbo is getting very hot outside from the leak

and is burning up. Also the y-pipe doughnuts are leaking but that leak is downward. Though there's no codes and it has good pickup. You can hear and smell the exuast. Man this thing is a real mess it's also leaking from the hp pump gasket into the valley down the bellhousing and from the reservoir gasket down

onto the timing cover.

[Bruce Amacker]

Started checking an 03 e350 for a engine knock, it seems to be from the drivers side front area. Im going to pull valve cover

and unplug 1 inj. at a time to see which cyl it is. Anyone ever change an injector for a knock?

 

On mechanical injection motors, yes. If one injector overfuels, it will knock hard like a broken piston. How do the Perdels look in scan data? There's a cutout box for disabling injectors on a 7.3, but you probably don't have one.

 

 

 

[joshbuys]

There's a cutout box for disabling injectors on a 7.3, but you probably don't have one.

I'm at a dealership that's been around forever and we don't even have one!!!! My old dealer had one and it was GREAT!!!! Sucks having to diag 7.3 miss without one after having used it!!!!

[Keith Browning]

Originally Posted By: Mbl35

Started checking an 03 e350 for a engine knock, it seems to be from the drivers side front area. Im going to pull valve cover

and unplug 1 inj. at a time to see which cyl it is. Anyone ever change an injector for a knock?

On mechanical injection motors, yes. If one injector overfuels, it will knock hard like a broken piston. How do the Perdels look in scan data? There's a cutout box for disabling injectors on a 7.3, but you probably don't have one.

 

 

 

 

 

Okay, not a common problem but I have had 7.3L engines where an injector was loose and fuel was leaking fuel into the cylinders. They knocked real bad. Also, I had one 6.0L with a split injector tip and two 6.4L engines with injectors DUMPING fuel that you would have sworn were coming apart. Of course they had other symptoms besides a heavy knock... like a little smoke. Just a little!

 

[Mbl35]

I'll have look inside the cover for loose items, but this thing does'nt smoke though. Howbout a loose rocker arm?

[Jim Warman]

Had one recently with a broken valve spring...This thing presented multiple symptoms at different times.

[dieseldoc]

you can build a cut-out box pretty easy and cheaply. The hardest part is locating the square 40 pin connector for the engine harness. I have had my box built for about a year now I just havent been able to locate the connector yet. I bought a plastic pencil box and eight toggle switches(rated for 120v)and a couple spools of red and black wire. I drilled the holes in the top of the box for the switches and hole in the side for the wiring to exit. Solder a few connectors on and heat shrink. Attach the wires to the switches and labeled them for each cylinder. Ran the wiring out and covered it in loom. Now as soon as I can locate that dastardly connector I will be in business.

 

As far as the knock goes is it a fuel knock or a deep pounding type of knock? Has it had an injector replaced lately where a cackle injector got installed in the wrong cylinder by accident? I have seen where low fuel pressure can cause a fuel knock.