Mechanical vs. Electric fan - Page 2 - PeachParts Mercedes-Benz Forum

tjts1 · #16 07-14-2020, 08:03 PM

Quote:

Originally Posted by EDBSO

The fix worked very well for me.

I can't speak to a 1987 300sdl but I have taken a 1999 E300 turbodiesel from Yosemite Valley to Las Vegas going through the heart of Death Valley. The outside air temperature never went over 49.5 C which is 121 F Ran it with the air conditioning on high and it cooled the interior.

I so wanted to see 50C but after running for an hour and a half at 49.5 it never hit 50C. I wonder if the gauge is pinned at the maximum at 49.5C and 50C is not possible.

There were multiple hills with the warning to shut off A/C or risk over heating. I ignored them and watched the coolant temperature. Only on one long hill did the coolant temperature rise over 100 and I shut the a/c off for a minute till cresting the hill.

Either drove at the speed limit or 10 to 15 over it. Stopped at the lowest point in Death Valley and a couple of other places, even in stop and go on the Vegas strip the coolant didn't go over 100C.

I am frugal and handy with my hands and if you are also, then I would recommend you try adding some fluid

This fix is not my idea I googled it and found it on the web. Others have led the way before me.

That's nice. Sit in stop and go traffic at that temperature then get back to me. With electric cooling mine never exceeds 90c at all times with AC running.

rbtoj · #17 07-15-2020, 09:19 PM

I also pondered about installing an electric fan but always gave up on it because of the issue Mxfrank mentioned. I wonder, however, if an electromagnet clutch fan would be an alternative. It can disengage completely when the engine is cool enough (and/or at speed), and when engaged it is powered by the belt, so it's reliable.
Plus, the OM60x uses them, so maybe it's easily adaptable on an OM61X?

Mxfrank · #18 07-15-2020, 10:15 PM

They were only used on very early cars. The disadvantage of an electromagnetic clutch is that it's not RPM sensitive. So when it's engaged, it's essentially an engine brake. TJTS's issue is low RPM driving...no matter what mechanism you use to engage a pump fan, it will do poorly at low revs. There's no perfect solution.