Aloha from The Big Island of Hawaii,

My b-e-a-u-tifull
300 D is overheating coming up the
One big mountain,
Also known as the island of Hawaii.
I am keeping in step
Italian Tune-up in S
And the temp rises over 100 C.
Please help this Benzie Hawaii
With causes and solutions
for heat reduction on steep grades.
---Thank You
Aloha from the sunny Kona side

If your temps are normal when you are traveling on the level then you might need to flush your cooling system.

__________________
1977 300D Lost coolant while someone else was driving
1983 300D Can't run without oil
1985 300SD (gone but not forgotten)
1990 300TE 4matic Sold
1991 Yamaha Venture
1975 Kawsaki 250 triple
1974 Honda 200CL
1951 8N Ford
2008 Wildfire 650C

Or it could look like this.

The temp would go up to around 100dC whenever the engine was loaded up. I have not been able to see the car run with a clean radiator yet to determine if the fan clutch is working or not.

Remove the radiator and take it to a reputable radiator shop for a good cleaning.

Attached Thumbnails

 

__________________
Jim

Be very careful about this. The shop may "boil it out" and it may look fine when you pick it up. But, hold it up to the sun and you will see all kinds of crap in the fins. The radiator won't perform any better after you have shelled out $75.00 or so.

In discussing this with the local shop here, they advised that I go and get a pressure washer to blow all the crap out of the fins. Apparently, they had no means to accomplish this.

Is 100*C a problem? 120*C is overheating. 100*C is 20*C away from overheating. It's normal for the engine to run warmer during Italian tune-up than it would cruising on level ground. Maybe you're used to the typical damped and normalized temp gauges that don't fluctuate so the typical driver doesn't think something's wrong.

Sixto
95 S420
87 300SDL

with the above post. may not have a problem. some temp rise (100) is normal in climbing hills. i believe you have some big ones in Hawaii.

also, I am not sure how successfully one can boil out one of these modern radiators. I am thinking that the tubes are pretty thin and you will end up recoring and or buying a new rad if it is bad.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Aloha from a Rainy Big Island,
I am going to flush out with zerex flush,
having a bit of a time finding
Appropriate fulids,
Here in the Big Five-oh.
I will carry on
and take all the comments and threads
into consideration.....
Thanks Again

If you decide to clean the bugs out of the fins with a pressure washer, go easy or you'll spend the next three days trying to get the fins straightened out...