2006 d12d Crank sensor

Oil is coming from the injector harness at the back of the head on the driver's side. It is a piss poor design. You have three options:

1) replace the engine harness (most expensive option and it will eventually leak again).
2) They make an injector repair harness which involves cutting and splicing the old harness inside the Vectro box (less expensive but will also eventually leak again).
3) Cleaning and RTV sealing the pass-thru fitting at the back of the head. It requires removing the valve cover (as do the other options), disconnecting the injector connectors to create slack, pulling the harness out of the head enough to comfortably work on. Cleaning the ever loving crap out of the pass-thru connector with brake cleaner to get all of the oil out and sealing it with RTV to about 6" beyond the connector. This way requires 2 or 3 days as you need to make sure the harness at the pass-thru is completely clean/dry and that the RTV has cured completely before reassembly. The harness sits in a little well in the head that fills with oil and stays filled even with the engine off. The connector is sealed with epoxy from the factory, but the heat from the engine shrinks and cracks the epoxy allowing oil to seep past the wires and outside the head. Most of it stays trapped in the loom and works it's way down into the Vectro box where it leaks out (cheapest and easiest, but also most time consuming fix).

 

I'm not on here a whole lot. It might be easier to keep it in the forum. I get e-mail notifications when there's a new post. Also easier to get to if you pull the dog house off.

 

My advice to you is replace both cam and crank sensors at the same time(because the vectro box will be open), Injector harness i'd replace it with the pigtail splice kit AND THEN rtv the heck out of the new one to prevent from it happening again, reason why i say this is because if you start playing around with your old one, you'll probably end up breaking it by accident because they become brittle and fragile... just my two cents

 

volvo dealer is my recommendation, I'm that guy that likes to put volvo parts on volvo engines, cummins parts on cummins engines, etc.. with the exception of certain things, but sensors and wiring i highly recommend OEM parts

 

I doubt anyone makes an aftermarket injector repair harness for it anyway.

Volvo 21625276

All dealers charge different prices, but the list price is $373.88

The full engine harness is over $1,000

 

If your splicing this in yourself, PLEASE, and I mean PLEASE DO NOT CUT all the wires at once, you splice this bad boy in, ONE wire at a time. Its a tedious job. You will have alot of connections to make, the harness comes with heat shrink tubes and butt connectors. One wire at a time because the new harness has all white wires.

Tools needed :
- Digital multimeter
- X-acto knife
- bare butt connector crimping pliers(long handle if possible)
- side-cutter plier
- heat gun or micro torch

So you have the valve cover off already and vectro box open, disconnect the truck batteries, disconnect all the injectors and engine brake solenoid valve, pull out all the wires of the harness inside the vectro box that come out from the injector harness loom, brake clean and dry all wires so you don't have ANY oil on your hands and connections while doing the job, BE CLEAN. Have your new harness laying on the intake manifold, take the knife and scratch the coating off a small section of each wire of the injector harness in the vectro box, but not too far in, preferably closer to the loom is better. Then use your multimeter set on Ohm's, I use the Diode function cause then the meter beeps for me and its quicker, start one #1 cylinder and pick a pin on the plug, then probe the exposed wires at the vectro box till it beeps or reads resistance. Make note of that wire. Then on the new harness probe the same pin, and find the wire that makes the meter beep or read resistance and splice that wire to the one in the vectro that's been noted. Make sure to slip on the heat shrink tube before crimping your connection, always tug the connection to make sure its tight, and heat shrink it right away before moving to the next wire, make sure each connection is as clean and proper as the next, you only want to do this once... You'll have more connector pins then wires, because cylinders 1,2,3 share two commons and 4,5,6 share two commons.

Hopefully this helps you

 

RTV only last so long maybe 6 months if you are very lucky all volvo d12 have this issue nothing new best way is to get the pig tail of whole harness depends on vin number somewhere around 700 to 850 for whole harness need a valve cover gasket as well not really horrible to change the splicing is more of a headache than anything considering the amount of wires that need to be spliced