Bosch diesel injector replacement

It’s been a fun day working on my truck, and I thought I’d share a few pictures.

Some background: I’ve noticed an occasional knocking at idle and under heavy acceleration, which can be caused in a diesel by a leaking injector. A fellow DMS member was kind enough to lend me a scan tool which confirmed a negative fuel balance rate for one injector, and allowed confirmation of the diagnosis by shutting that one off and observing that the knock stopped.

I ordered a new one from Injectors Direct and installed it today. The truck is purring like a kitten again!

The old one, buried back behind the fuel hoses and glow plug controller.

Several extensions and a crowfoot flare wrench were required.

Old injector, new injector, the hold down bracket, and the old fuel line.

Grimy injector bore before cleanup.

New injector, installed and ready to test!

Video, or it didn’t happen.


Thanks for sharing that repair!

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For my next trick: re-routing the PCV line so as not to dribble condensed oil mist down the back of the engine.

(edit: also prevents the intercooler from becoming a coke-plugged mess.)

I’d forgotten to post these. I used a USB camera to help me clean out the injector bore. Enjoy!

Duct tape and a series of hoses were used to make a custom mini-vac with variable suction.

Almost clean.


A few options :
1- reroute the PCV to the ground like in the old days (might stain the driveway tho)

2-install a Mann Hummel Pro Vent

and there are others…

Neat! I didn’t know #2 existed. I like that option.

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Mann Hummel is the real world’s filter company - the Pro Vent is well made, readily available.

Just trying to help…


Thanks for the tip. Every little bit helps: injector failure on these trucks is blamed on either the 7-micron fuel filter (too wide) or the ultra-low-sulfur diesel fuel. I’ve solved the latter with an additive (Optilub XPD, chosen because of an independent test) and plan to solve the former with a lift pump -> water separator -> CAT 2 micron filter adapter. The stock high-pressure injection pump has a gear lift pump to suck the fuel from the tank, which does not have enough cowbell to use the 2 micron filter w/o some help.

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Then there is the option of a tin can option as well. CCV mod on the 7.3 many have done that.

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Do I want to resurrect this thread? Hells yeah!

ze German man iz wery conwincing

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