Save your head, upgrade your aux fan plug!!!
 

ANY aluminum head engine (the majority of engines, BTW) will suffer greatly by being overheated.

Oddly enough though, this is usually caused by a simple fault.
The auxillary fan fails to come on when needed and an engine rapidly overheats when stopped, or driven slowly in traffic.

And many times it is simply a matter of the electrical connector plug gets corroded from salt, etc. because it is usually hanging down near the bottom of the radiator.

Solution and preventive maintenance.
Replace any european plug connector with a Toyota connector from a salvage yard. You will see when you pull one of these apart, no matter how old and grungy, that the contacts are as new. They use a nifty O-ring seal in their connectors which greatly contributes to the overall impression of Toyota longevity and quality.
A small but significant thing like this can upgrade any engines chance for survival.



:D

Gee, thanks Ed!

Guess nobody has a reply or comment?

Good tip on connections. My old buick had those o-ring seals on everything too. Wonder why MBNZ doesn't? youd think that they would especially? I thought that the fan wasn't supposed to come on untill 107*C, which would mean you had more problems then the fan wouldn't it?
R

connectors
 

thanks for the tip and warning ed, but i'm afraid that if i put anything japanese in/on my car it will 'know' it and get back at me somehow no matter how good my intentions were :D

for sure there are probably many connections corroded in cars of this age and i also have had to clean a few on mine sofar

Hi Ryan

This was my experience with a Saab 900Turbo.
I didn't really have problems with the car, but if you are going up a hill in the summer, with the temp in the 90's, and with the AC on, you will overheat without this fan. A further complication was that my chain had many miles on it, and the engine was pinging.
An even further complication was the driver! She was driving in too low a gear, and kept it floored and complained that it didn't have any power...Hoo Boy...

My assumption is that a similar problem would occur with any car, not just mine or a MB diesel, and that is why I made this post.
It is something that took me a while to figure this occasional overheating problem out, because the fan would sometimes work, so I ruled out a problem with the fan motor, and I replaced the sensor that turns the fan on and off, so I figured there wasn't a problem. But I rigged up a tell tale light to the dash so I could keep an eye on the fan operation, and sure enough, when the temp soared, I noticed the light wasn't on either/no fan operating. I jiggled the connector when the engine was too hot, and the fan started to run.

Same thing happened to an Audi 5000, which warped the head, etc.

Perhaps I will install a subtle LED light on the dash to watch for fan operation, just for peace of mind. :cool:

correction;

...she was driving in too high a gear...

At what temperature is the auxillary fan suppose to come on?

The aux fan comes on at different temps in different cars. For my 1987 300D, the low speed aux fan turns on at 105C, and the high speed turns on at 115C (I think.) You need to check the Electrical T/S manual for your chassis.


Regards,

OK I'll asked . Is there any way to test the fan in advance?:o

Interesting thread with the idea of using a Toyota electical connector. The electricals in most MB's I've encountered seem like they were designed by mechanical engineers, rather than electrical engineers, if that makes any sense.
Anyway, years ago we started using a silicone grease and a weather boot to seal (cable TV) F-fittings that were used outdoors. We'd pull them off after years outdoors and the connector would still be shiny and bright. Wondering if something similar would help prevent corrosion within our German connectors (after a good cleaning with a scrub brite pad or similar) while still maintaining the "stock" appearance. Just a thought....

Why not use just the silicone grease?Is it a special type for electrical use?I have some silicone brake grease,would it be suitable?Don't I ask a lot of questions?:D OK bye.;)