Biodegradable Insulation???
 

A friend of mine has just returned from his local MB shop with soem VERY unusual information. He has a 1995 E car, and was informed that MB used biodegradable insulation on the wiring. Due to this he will be needing the harnesses replaced. He was shown extensive deterioration of the insulation and has been suffering shorts in some of the engine management systems. Does anyone know if this is true, what is the recourse if any or the permant repair.

Thanks

This is one of the most frequent problems on these cars.

If you do a search for wiring harness, you will find that there have been numerous problems with the insulation on the wires breaking down and causing shorts. The repair is to replace the harness.

-Good luck

Strange but true
 

Yes, be SURE to search this site. There is an engine wire harness that includes most of the upper engine accessories and engine management connections. Is the car in warranty? It's a warranty repair. If the car is out of warranty, how friendly is your friend with his dealer's service department? There may be a chance for a goodwill replacement. I managed a 50% goodwill replacement on my '92 500E with 109K miles. But I spent more than a few thousand in service at my local dealer over the past year. When the old harness came out, the insulation was cracked throughout, like every half inch. It was a mess. Good luck!

MB "goodwill repairs" are usually done if you are the original owner, bought the car at that dealership and have had it regularly serviced there. I have yet to hear of any dealership that would eat the cost of this repair if it were otherwise. MBUSA will not acknowledge anything about this repair even if it is a well know bugaboo.

$800 is a good price, about what I paid, although I think 5 hours is way too long to do this. An experienced MB Tech should be able to do it under 2 hrs, it is only a matter of unplugging all the connectors, taking the old harness off, then threading the harness through the engine compartment and plugging in the new connectors. Some disassembly may be required as there are some pretty tight spots where you need access.

Someone once posted about the history of this misbegotten use of biodegradable insulation. I don't think it was meant to disintegrate while in the engine :rolleyes: . Someone took a shortcut somewhere and did not do the appropriate thermal decomposition testing. I believe it is the heat in the engine compartment that causes the problem. Even then, it is not as bad as with some other car makes where the insulation crumbles to dust!