Bad Engine Harness
Of course the engine harness is the most time consuming and not covered under warrenty. Estimate of cost is $2000 to replace a $360 harness.
Luckily all the parts except that one are covered. So my question would be how difficult would this harness be to replace. The car is back home in the driveway and I have nothing but time so if anyone has changed this harness out and can give any info I would appreciate it.
Apparently this harness connects to the Cam Lobes Sensors, The O2 Sensors, the ECU and Front Sam.
Thanks!
Dave
PS I have called MBUSA and filed a complaint and they refuse to cover the harness.
Last edited by Djcoak; Dec 13, 2008 at 10:55 AM.

Of course the engine harness is the most time consuming and not covered under warrenty. Estimate of cost is $2000 to replace a $360 harness.
Luckily all the parts except that one are covered. So my question would be how difficult would this harness be to replace. The car is back home in the driveway and I have nothing but time so if anyone has changed this harness out and can give any info I would appreciate it.
Apparently this harness connects to the Cam Lobes Sensors, The O2 Sensors, the ECU and Front Sam.
Thanks!
Dave
PS I have called MBUSA and filed a complaint and they refuse to cover the harness.
That said - amanonfire & others have done the job - hopefully they will come to your assistance
Last edited by Glyn M Ruck; Dec 13, 2008 at 05:25 PM.
The problem is the harness goes under the car (O2 sensors, oil sensor, CPS) and to the injectors, so its a bit of a pain.
More tedious than hard.
The problem is the harness goes under the car (O2 sensors, oil sensor, CPS) and to the injectors, so its a bit of a pain.
More tedious than hard.
Thats funny my dealer is quoting 18 hours. If it were only 6 I would have had him do it LOL. Does anyone have a picture of where the harness starts and ends? Thanks!
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6 hours labor seems fair, 18 hours sounds like they really like you. Heck, an engine swap probably doesn't even book at out at 18 hours.
The Best of Mercedes & AMG
Good luck for those of you that still drive them, you need it
And if you happen to live in the SF bay area, my mechanic is awsome.
Good luck!

Spend the $300 & do the job yourself. It's a bummer but had you bought a V6 you would not have these troubles.
If you want something boring but ultra reliable - buy a Toyota.
Like buellwinkle said, sounds like they really "love" you. Go somewhere else.
Most likely your engine harness can be saved, once you have it out soak it in degreaser overnight, rinse, repeat. Any oil left after that will slowly seep out, yet not in a large enough quantity to do much harm.

"To clean the harness properly you really need to use a solvent like Hexane. The trouble is that Hexane is nasty stuff - If you go this route - ON NO ACCOUNT INHALE AN EXCESSIVE AMOUNT OF THE FUMES & WORK IN A WELL VENTILATED AREA - excessive Hexane inhalation can lead to numbness & temporary paralysis of arms & legs.
It's a constituent of gasoline, glues etc."
Hexane will literally extract the oil from the harness due to it's chemical composition
Thought the harness alone cost almost $1000


Last edited by Glyn M Ruck; Dec 21, 2008 at 04:41 AM.
and here I thought R20K for a brand new Toyota 4AGE 20v motor is expensive...For R30K I could probably get a M112 motor (recon), gearbox and have it fitted I'm sure...
Just crazy
"To clean the harness properly you really need to use a solvent like Hexane. The trouble is that Hexane is nasty stuff - If you go this route - ON NO ACCOUNT INHALE AN EXCESSIVE AMOUNT OF THE FUMES & WORK IN A WELL VENTILATED AREA - excessive Hexane inhalation can lead to numbness & temporary paralysis of arms & legs.
It's a constituent of gasoline, glues etc."
Hexane will literally extract the oil from the harness due to it's chemical composition
Oil seeps through the harness and into every sensor connected to it. Replacing only the harness doesn't remove the oil from the sensors. Moreso, most people don't notice the affect of the oil in harness issue until 1L or more has leaked out, cause the ECU is more likely to complain about being a L low in oil before the O2 sensors get messed up enough to throw a CEL.
So the minuscule amount of oil still left in the harness is nothing compared to the > 1L that has already seeped into components. Cleaning it with some degreaser should be good enough, and some preventative maintenance to reclean the connectors 6 months later should suffice.


Quote
"First:
replace cam sensors
add isolation wires
clean all connectors with electrical contact cleaner
If problems persist:
replace O2 sensors
replace engine harness
If problems persist after that:
cry
replace MAF
replace ECU
unquote"
There are many others. Now you say it's OK to have a partially oily one????
How much oil causes an O2 sensor to misread ???
Then above you start talking about dealers replacing the harness & not the electronics??? - this is nonesense.
Under warrantee the dealer will replace all the elecronics & sensors FOC - what the dealer & MBUSA won't cover under warantee is the harness.
Wake up
How much oil causes an O2 sensor to misread ???
Then above you start talking about dealers replacing the harness & not the electronics??? - this is nonesense.
Under warrantee the dealer will replace all the elecronics & sensors FOC - what the dealer & MBUSA won't cover under warantee is the harness.
Wake up

Non-sense, I listed many of the electronics that are connected to the harness - find me a repair sheet where the dealer replaced them all. You cannot. The dealer only replaces what is a problem, I spoke with my service manager about it and asked if I was under warranty about replacing everything, and he said it'd be a fight with MBCanada since that's not the procedure.
Now MBUSA may be different than MBCanada, yet I still doubt you can find one repair order where all the electronics I listed were replaced.


