jpganman

I started having trouble with hard starts on my 93 400E. My service shop saw richness on the plugs, caps were getting mucky (had them replaced recently) and no codes were showing up on the scanner -

They decided it was the wiring harness as Mercedes used some biodegradable plastic which breaks down causing a failure, and apparently had a recall campaign that the previous owner did not participate in and it ended in 2001.

The service guys also said not to use certain fuels (BP, Texaco, QT) but to use Chevron.

My car is running fine now but I am wondering if this is just a band aide to a future problem, and the repair was quite expensive @ $1100.

Please give thoughts if any of you can help, and thanks in advance for doing so.

400E fan

Don't know if I can be of any help, it sounds like your problem is fixed.

But maybe I can lend some comfort, at least. $1,100 is a pretty good price for a V-8 harness -- both upper and lower -- installed. As far as I know, there never was a recall of the (clearly defective) wiring harnesses M-B used on the E-series in the early 90's. If someone got theirs done under warranty, they were either very lucky or had one hell of a good relationship with their dealer.

The good news is that new (OEM) harnesses use a completely different insulation, and should last the remaining life of the car. Replacing it is certainly not a band-aid fix.

I have no idea how the brand of gasoline intersects with the insulation of the wiring harness, though...

G Man

I paid $517 for my upper wiring harness(500E) two months ago from Fastlane. I installed it myself in about an hour. If they only replaced the upper, it sounds like they are really proud of their labor. If they changed both, I agree with 400E 's statement. I was shocked at the condition of the harness after only 59K miles.

jpganman

Thanks to all for your responses, I sure hope the harness fix works - this car has been awesome (I have owned it for almost 3 years) and have had very little trouble. My brother in law has a 92 and he put Bilstein Shocks on the car and says it makes a world of difference in the handling so if this wiring harness is the fix and I don't have to put more cash into the car I will opt for the Bilsteins.

zeronero

Personally I think that is total BS. I've put nearly every brand of fuel available on the west coast into my car and have never had an issue. I also put in 87 most of the time; I've got almost 200k on the car and never had an issue related to fuel.

By the way aren't Chevron and Texaco the same company and the same fuel, they both have Techron?

ebennz

i'm sorry, you're a little mistaken.

the goodwill harness recall was for the m-104 6 cylinder motors.

the BAD NEWS the wiring harness' for V-8's were NEVER upgraded. you get the same thing.

i hope '400efan' got both harness' changed for $1100, but i kind of doubt it.

i just had my lower harness changed last wednesday, 80.00 part, 110.00 labor at the stealer.

my tech [25 year mb master tech]said he thought i was crazy and no way these harness' [both of them] were bad. he told me i was absolutely correct.
he told me this saturday on a roadside call.

jpganman

Thanks for the insight. Why did you need the lower harness replaced, was it for the same plastic breakdown as the upper harness typical problem?

My main concern is that the $1100 repair (dealer quoted about $1800) is not the actual fix for my hard/no starts. Also, prior to the harness change I could smell very rich fuel after startup and the tech told me that if the harness is bad the computer can not send correct info and the car basically starts trying to compensate resulting in my fuel smell, richness on the plugs, and residue in the caps.

jpganman

Ebenz,

Dumb question I am sure, but what is the difference in the .030 and the .034 designations in your listing of cars in your post? Is one and E500?

jpganman

Ebennz, I just figured out the designation.

ebennz

jpganman

i have read and researched the 400e trouble spots.

a lot of 500e guys mentioned the lower harness also defective because of substandard material-like the other one...my lower harness was toast.

it was also a lot cheaper than the main harness.

when was the last time you had a major tune with fuel filter replaced up by a qualified mb tech?

are your plug wires original?

how is your fuel pressure regulator?

have you ever replaced ALL of your fuses?

this is very cheap and great insurance