Have the airbox off of the '93 500E to swap filters and clean in and under the box itself. Took the opportunity to look around on the engine top, which is normally invisible under the airbox and front plastic cover.

Instantly noticed that there is a brown ground wire coming off of the long black wire tray which sits atop the left-side fuel rail. That wire is covered with insulation which is without any question cracking and failing along its entire visible length.

Sounds like the infamous OE wire harness bug. What do y'all think?

This is less unfortunate than it sounds. This car's at only 50K and still has active Starmark coverage on it. I assume that there shouldn't any trouble at all obtaining a replacement on MBUSA's dime if I present the car at a competent dealer, yes?

s/b

YES on both accounts! Shouldn't have any warranty problem at all. IN fact the selling dealer should have replaced the harness BEFORE certifying it.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
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MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
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Retired Moderator

Have the dealer check ALL the underhood wiring harness. Insist the Tech slit open all the covers and check them.

s/b-

let us know what happens w/ the Starmark claim, will you be taking your 500e to SF Fact Authr Service @ Clay or the another shop?

you may wish to do a couple of other super do-your-selfr's - - cheap insurance items:
>power steering cloth wrapped hose (search)
> oil check relief valve (search)


-fad

Make sure he looks at the EA

__________________
euro 287
Mercedes Technician 7 Years (retired to Hyundai)
2000 Dodge Durango
98 Mazda truck

Following up here:

Wow! Incredible what you find when you look closely. When I first pulled the airbox off, I took one casual look around and said, "All OK." It was pure luck that I noticed the one cracked ground wire and dug in more deeply.

Well, looking more closely, I found *massive* deterioration and damage to the harness. At least one cylinder apparently has no injector pulse delivery, as the wires appear to be too far gone inside their jacket to be able to conduct. Just because things look neat on the surface is no guarantee.

The car is benched until I can tow it into a dealer. Thanks for your comments, guys! Your standards of technical excellence are astonishing. Responding to a couple of points here:

Kebowers says:
>Have the dealer check ALL the underhood wiring harness. Insist the Tech slit open all the covers and check them.

Yeah, after what I just found, I can absolutely see the sense in that. The harness covers apparently provide little or no protection to the wires inside; they may even accelerate the insulator breakdown -- heat retention, maybe? Wires were literally disintegrated at one spot inside the cover. Just gone.

euro287 says:
>Make sure he looks at the EA
Roger wilco. Quite a list! Just how many harnesses are there on an M119 engine? My previous impression was that there were two master harnesses, one "top" and one "bottom".

If someone has a definitive list, I'll politely ask the service advisor to have every single one looked at.

fad said:

>you may wish to do a couple of other super do-your-selfr's - - cheap insurance items:
>power steering cloth wrapped hose (search)
> oil check relief valve (search)

Yep. Thanks for the reminder. P/S appears safe for now but will get worked on. I have the parts list for check valve + relief valve + o-rings and I'll do the full install at home, since I'm competent to handle that work. Unless that is a Starmark item -- no one has ever described the oil mods as a warranty-coverage circumstance.

>let us know what happens w/ the Starmark claim, will you be taking your 500e to SF Fact Authr Service @ Clay or the another shop?

Fad, no, the car and I are not in SF, I'm travelling back East. But I will follow up on the dealer/MBUSA response to the problem, and rate them for satisfactory performance.

Frankly, I have heard complaints from others about both MB-of-SF, and Autobahn, which two are the sum of dealer service departments on the Peninsula. No problems myself with either, but on the other hand, I haven't ever brought either one a big job like this.

s/b

Okay, following up, as promised:

Took vehicle to the nearest dealership with a written symptom complaint sheet (telling them exactly where to look). Received a call from the S/A that afternoon telling me that they concurred in the failing-harness diagnosis and that they would perform a full replacement. Tech was asked to inspect the other underhood wiring; reported no problems.

The new harness apparently had to be overnighted in (from Germany?), so it was a two-day job. When picked up, another S/A said that the work was "fully covered", but didn't specify whether it was Starmark coverage or a goodwill replacement. I suspect that anything that -does- have Starmark just clocks in under that policy. Fewer hoops for the S/A to jump through on the paperwork.

Now, with the replacement harness, the car is better than ever, and it was pretty amazing to start with. I suspect that it had been erratic on firing one injector, as the wires were really bad in that single case. Everything else had extensive cracking, but it was being held together by the jacketing around the wire pairs.

We've learned an important lesson today: inspect your harnesses! If it happened on this vehicle, it can happen on any car from the vulnerable production runs. This is not a neglected beater car. It's one of the best-kept 500Es I have ever seen, dealer serviced since new, and had passed a Starmark inspection in the low forties, not all that long ago.

But if I hadn't looked closely, I would have missed the cracking. It's that subtle. Most of it is hidden underneath the harness jacketing and the injector boots. I found that pulling the boots off was the fastest and least invasive way to scope out the problem.

Impressive that the car still started and ran quite well with the wires as messed up as they were. Now, with that fixed, hopefully the car is okay for the rest of its lifetime, and given the overall solidity of everything else, that should be a good long time.

s/b

Just a note here, you cannot check the throttle actuator harness unless you split it open. Most techs overlook this until it causes a problem such as no acceleration or a cruise control problem.

__________________
euro 287
Mercedes Technician 7 Years (retired to Hyundai)
2000 Dodge Durango
98 Mazda truck

Thanks for post s/b

what dealer did you take your car to?

-fad

Duplicating answers here, as there are two active threads about harness issues:

The replacement was done at MB of Devon, in Pennsylvania.

As far as the throttle actuator harness goes, if the only way to confirm damage is with invasive testing, that's a tough one. I may just have to wait it out and see if it is okay.

s/b

s/b

My only question would be. If this is a "STAR MARK" car, why didn't they change the harness during their 5 billion point inspection before they offered it for sale? I have been a Mercedes tech for 30 years and I've seen the corporate attitude go from "we are proud of our product" to the American attitude of " let's wait until someone *****es or files a lawsuit.

Post Script: A friend of mine purchased a "previously owned" BMW from an authorized BMW dealer a few years ago, and it also went through a billion point inspection. He took it off the lot with the rear brake pads down to the minimum. Maybe anyone buying one of these "previously owned" cars from a franchised dealer should have the car inspected at a reputable independent service facility like MB Autowerks first. Just my opinion. Isn't the internet wonderful?

Peter
Peter

__________________
Auto Zentral Ltd.

My 93 300E was Starmarked in 1997, and the engine wiring harness wasn't replaced during the billion point inspection.

It went out at 107,000 miles, and the dealer replaced it as a goodwill warranty. The car was purchased there and all of the maintenance was done there.

It still begs the question why they didn't do it in the first place...

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

I've had fact authorized service in SF review my '94 E320 Coupe Starmark for the wiring harness issue....

...(2) two weeks later I requested Smythe European's help (fact author service) in San Jose, CA to review for a 2nd opinion....

Smythe replaced the main engine wiring harness immediately under Starmark- no questions>>>

....and I did mention prior to the Smythe's inspection, that SF fact authorized service reviewed this area 2 weeks prior and gave it a clean bill of health

I have done business with Fact Authorized Sales and Service:
1) SF, CA : European Motors Ltd in 2 locations
2) Pasadena, CA: Rusnak
3) Newport Beach, CA: Fletcher Jones
4) San Jose, CA: Smythe European

....all of these MB businesses appear to be "managing" their warranty costs ...some more aggresively than others, but the customer really needs to be armed with a clear understanding of what their specific warranty covers and ensure that they get what they have paid for in terms of warranty coverages

-fad

fad,

Forget the warranty. What happened to the days when MB was proud of their product and wouldn't have let the wiring harness slip by? Considering the premium price one pays for a Starmark car, that's what it is is a car, perhaps one could pay THOUSANDS less for a private party car. I'm not hell bent against Mercedes Benz AG. I just appreciate the fact that the internet allows us consumers an opportunity to voice our opinion and take some control. I'm appealing to the thinkers out there. I know i'm going to lose some of the flag wavers on the way, but I understand.

Peter

__________________
Auto Zentral Ltd.

Have to follow up here, after starting the whole thread:

Yeah, I'm frankly *amazed* that the car could pass Starmark with the wiring harness impaired, and easily detected as being such. I mean, if there is any single classically characteristic defect in the early 90s vehicles, the harness is it. Definitely, a deterioration of service standards is taking place.

Although some of this may simply be MBUSA hoping that with enough time, the camel will learn to sing (ask me privately by PM if you've never heard that old joke, or just dig it up on the net).

So here's the verdict on the harness rework: excellent job. We just drove the car pretty near all the way across North America. 3800 miles of tough, fast driving in hard conditions.

The 500E started instantly, pulled like a freight train, purred like a kitten, executed a dozen letter-perfect panic stops, and soaked up uncounted potholes with great calm. It was totally unfazed by climate extremes from freezing cold in the upper Midwest, to an indicated 108F in Las Vegas. Altitudes from below sea level to above 9600ft at the Sonora Summit. This is quite the car.

It also has a very pleasing ability to make annoying drivers and their vehicles become very small and far away in a short time. Or at least it can do that where there is room to let it run. We are unfortunately no longer out in those open reaches.

The first hint I had that we were back in the Bay Area was when I watched some kid in a riced Accord pass someone who had been hogging the fast lane; this kid did it in the gravel on the left shoulder, blowing past someone who was already doing 80-plus MPH.

And we then looked in the rear-view mirror to find a soccer mom in a juggernaut SUV who was doing her mascara and talking on the phone, one-third of a car length off our back bumper, this also at 80-plus.

Yeah, definitely home again. Home to too many rude, dumb, dangerous drivers packed onto increasingly overloaded roads. Hmmmmm. I suspect that the urge to take the big dog back out into the wide open spaces is going to come up again soon. I had forgotten how much fun it can be to go driving.

s/b