I believe that this problem is accelerated by heat.

My 1993 400E has a real problem with heat on top of the engine. MB simply shoe-horned this engine into an engine compartment that is too small for it. Putting the Battery in the trunk and the Pressure Accumulator behind the front wheel (Great choice!!) does't solve the problem that there is simply NOT ENOUGH AIR CIRCULATION under the air cleaners.

Simply put, when the fans kick in, there is simply not enough air pushed under the air cleaners unless you are moving!


Once it hits 25C and sunny DON'T run the A/C and hang around in traffic. And DON'T park it in blazing sun.

My 400E doesn't have a harness problem (doesn't get driven in the heat) but we have had problems with the throttle body overheating and putting her into Limp Mode.

I talked to some guys who build race cars and they say this is a common problem for them. They suggest running some piping to ventilate the area, with a scoop behind the fans - haven't tried this yet, There's not a lot of room for anything.

I am tempted to re-engineer the air cleaner manifold - anyone tried removing it?

__________________
1993 400E
Calgary, Alberta
CANADA

I never had mine overheat even though my wiring failed. It may make it fail faster but many euro cars of the same vintage had issues with environmentally friendly coatings on the wires.

__________________
92 500E Silver 66k
82 Porsche 911SC 84K
68 Cadillac ( Gone Now )
03 Suburban Z71 200K
85 300SD 217k From Original Owner ( Dad )

Guys,
Did they improve by the '95's? I have a E420 and live in the second hottest area of the US. 115F is not uncommon. For the next 60 days we will be 104-115F. For the last 60 days we were 95-108F My car is the coolest running of any of my Mercedes over the years. I am hard pressed to get to 100C. I noticed that the frame will support the largest radiator, the E420. Perhaps you have a smaller unit. I will admit that for the last 10 years down here, I always raise the hood when I put the car in the garage. It is amazing how much heat boils off. I replaced the wiring harness as a maintenance item not because I had to.
Anziani
'95 E420 126K
'93 320CE 206K

I'm not talking about your coolant temp. If it gets around 100C that might be a clue, but if you lift the filters you'll find that the temp around your throttle body is seriously high.

It is a fact that biodegradable plastic degrades faster with heat. That is why the engine harness is the one that causes the most problems. The other wiring is the same - it just doesn't get so hot.

The throttle body malfunctions if you overheat it. I believe that getting it rewired fixes that problem but I don't know how - it doesn't make sense for it to be the wire since it corrects itself when it cools. It seems to me it must be an electrical component (try over-heating your computer!) Obviously you don't want to keep overheating it or it will fail permanently - also your wiring will be fried.

Notice also, if it's hot and you park it, the heat rises to the top of the engine as the coolant is not circulating any more. So that doesn't help. Get out of the traffic and limp for 5 mins. Stop the car and re-start it. It should cancel limp mode if it has cooled off enough. Just keep it moving. (A/C off!)

Having grown up driving some terrible bangers I also open all the windows and turn the heater up high! The heater just works like your radiator only smaller.

All this sounds a bit silly but nothing is more silly than $850 for that little bundle of wires!!

__________________
1993 400E
Calgary, Alberta
CANADA

.

NO, nothing was done until 1996 - 1997.


.

Yes, the biodegradable coating will break down faster when exposed to high temperature.

FYI; Even if the wire harness thermal cycles between -3°C and
+35°C, the chemical engineered biodegradable wire coating WILL break down.

This was design intent following European Union law, and mandated by Mercedes Benz Management.

The options are:
* Replace the failing harness with a factory NEW harness.
* Remove the harness, and re-cover all wires.
* Remove the harness, and replace all wires.


.

Ken,
You might want to contact this guy. Well known for rewiring ETA's Mercedes repair and restoration
Also BBA Reconditioning in the Boston area does the same. All use military grade wiring which has a higher rating than automotive.
Does it really get that hot in Calgary?
Anziani

Thanks Anziani, unfortunately my car is about done. We use far too much salt on the roads here and I can't keep up with the rust much longer.

Love the car, best drive I've ever owned and that V8 is incredible. Might be interested in buying something form the lower States but haven't looked into it properly (coming back across the boarder!). I'm thinking a 2003/2004 E Class. Not sure what to do with mine though - anyone need a good motor???

__________________
1993 400E
Calgary, Alberta
CANADA

If you buy a car in the US, is there a high duty to bring it into Canada? So Cal is a hot bed of Mercedes and the only salt we use is on the rims of margarita glasses. You can do a search on autotrader.com and use a zip code of 90020 which is a Los Angeles address to give you an idea of what is available.
Anziani

Yeah, If it's not made in N. America it turns out it's a mess! Looks like it's a non-starter.

__________________
1993 400E
Calgary, Alberta
CANADA

Well that sucks! My dad and grandfather were Canadians but emigrated in the early 1920's.
I would guess it was a lot easier then.
Anziani

http://www.peachparts.com/shopforum/video-forum/323007-m119-eta-throttle-body-rewire-process-pictures-1995-sl500.html#post2992389

We recently had a wiring harness issue on my dad's '87 SDL. He was driving along a main highway when smoke started coming through the air vents. Our indy recommended we install a fusible link to avoid a short such as what occurred in the future, but now we face a massive bill to snake out the old harness and replace with a new one. We hope insurance would cover it, but what has yet to be determined is if the cause was the harness itself, or perhaps a rodent got in and chewed through the insulation.

My concern is that this wiring harness issue goes further back than the model years I've seen referenced in this thread. Haven't seen much for engine fires on the W123 or 2GEN W126's, but I'm curious what others have seen.

__________________
Never be ashamed to ask for help.

1985 300D
1987 300SDL
1970 Jaguar E-Type OTS
2002 Dodge Intrepid (Traded In)
2011 Ford Crown Victoria

Better hope its the rodent.

I think what defines the harness failure issue and affected models was the use of "eco-friendly" bio degradable wire insulation.
That stuff just degenerated while in the harness over time.
The new harnesses avoided the 'eco' stuff.

Hope the 'gecco' helps pay for the 'rat'.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

My 94 E320 failed smog so I replaced the plugs. It ran just fine. Took it to the smog check place and apparently the wire to the coil sagged and internally shorted so it was now a "Gross Polluter". I checked the 12V to the coils and the insulation on the wiring had turned to dust, letting the wires short out. Since a new set of wires would cost over $1300, I junked the car.
I think it is absolutely inexcusable for MBZ to not get their wire supplier to pay for replacing the defective product as wiring should last the life of the car.

__________________
'76 240D-Sold
'78 240D-Sold
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet- under restoration
'86 560SL 124K Miles-Sold
'94 320E Wagon, 74K Miles-128K Miles JUNKED
'06 E350 Wagon, 84K Miles
07 SL550, 14K Miles