OK, I am near Toronto, winter is coming, and I have an 85 300TD. I have been reading on some other sites about people removing there clutch driven rad fans to get better gas mileage. Of course these people don't live in the south. I wanted to ask the question here.

Do you think my car will overheat if I remove the rad fan for the winter? I don't think it will. Last winter my thermostat stuck open and even with the rad completely covered with cardboard the temp would not rise.

Comments??

Thanks

Peter

Are you really gonna save enough in fuel for it to be worth the chance?

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

Well, of course I would have to keep one eye on the temp guage, at least for a bit, to see that it doesn't overheat. But as I said, with a stuck open thermostat, I couldn't get the temp to rise at all, even with a completely blocked rad. What that tells me is that the car has tremendous cooling capacity, and I bet that the thermostat only has to open a tiny bit in the winter to keep the coolant cool. The car would probably warm up quicker as well.

Peter

I remove my fan. Be sure to get shorter bolts, stock ones will contact the waterpump body without the fan.

When I decide to remove it depends on the weather. When the daily high temp is 65*f or lower for 5 days in a row, I know it's safe for my engine to run without the fan or shroud (keep a close watch on yours for the first few weeks until you learn what it can take)

Attached Thumbnails

 

The fan goes!

Peter

Please post before-and-after fuel economy numbers.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

why not replace the mechanical fan w/ an electric one?

You can get an automatic thermostat/relay setup or just get a heavy duty switch and turn it on yourself when/if need be.

I did that on my jeep and there was a definite "seat of the pants" improvement in performance.

__________________
Cheers,
Robert

It's insignificant. The MPG difference will probably fall within range of the "random variables" category. Meaning, it could be the fan or it could be the weather/temperature/road conditions/etc.

In any case, here are all my MPG marks since I started driving my 240D (with 300D engine) November last year.
MPG
20.34 11/31/05
17.73
20.85
19.53
18.93
22.21
20.4
19.24
20.71
20.48
12.57
13.53
19.8
19.33
21.8
N/A
N/A
N/A
24.366902238
23.007088671
21.953
23.350732202
23.079413908
21.51469777
20.522912567
26.528166201
22.130657274
24.541070317
21.993022903
22.457258766 12/1/06

The 12.57 and 13.53 were because I had a major fuel leak on a long highway trip.

i ran my 83 300dt that way for a while. no problem. keep an eye on the guage though. but as far as the mileage goes....think of it as saving wear and tear on your fan clutch.

tom w

__________________
[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.

What's the point of removing it? If the clutch and thermostat are both working correctly it will not make any difference to mileage, performance, or warm-up time. If you happen to get stuck in traffic on a warm day you may overheat. A few weeks ago, my clutch failed (so it didn't engage) and my 300D got close to 120 C when I sat in traffic for about 5 minutes on a 60 F day (even with the electric fan running). My car warms up to 80 C in about 5 minutes regardless of the outside temperature.

Interesting. Some claim over 30 mpg for the 240D. My '82 automatic 240D has been running 22 to 24 mpg in town, and 25 on the highway. So far, never below 21. I'm feeling a bit better now.
I am thinking of converting my 240D from a solid fan to a 300D clutch fan. Any thoughts on possible power/mileage/noise improvements if I do?

Happy Motoring, Mark

__________________
DrDKW

I disagree, upon cold startup my experience has been that the allegedly 'clutched' fan is still moving ALOT of air


That statement I agree with... however...


these things don't put out much heat @ idle, I'm surprised that the electric fan couldn't keep up.... Is there a tranny cooler in the radiator?

__________________
Cheers,
Robert

yes.

i dont know how much difference a clutched fan will make on a 240. the stock fan has what, five blades? the clutched fans on the 300 have what, eight? the clutch fan is supposed to freewheel when not needed, but with the fixed fan on the 240 while moving down the highway the air will be coming in anyway so turning it shouldnt take much energy. so really i cant see it making a big difference either way.

but a 240 fan on a 300 will probably be inadequate in severe conditions. like idling on a hot day with the ac on.

tom w

__________________
[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.

I have two diesels, an 85 300td and a small Mitsubishi truck. I will remove the fan on the truck because I know that it spins all the time.

As for the 85 300TD, Does the fan spin all the time? I haven't really looked yet but it seems to me that hot or cold, that fan is spinning when I start it up. Is it supposed to spin in the cold? Someone mentioned "freewheeling" does the fan still spin, but not as fast? How's that work?

I am really looking for faster warm-up times. I know that here in Ontario it is going to be cold for at least 3 months, no chance of overheating.

Thanks

Peter

The clutch is not locked up when cold so the fan is spinning at a slower speed than the pulley is turning.
I don't see how not having a fan will improve warm up times since that is controlled by the thermostat. If no water is passing thru the radiator, a fan blowing over it is not going to make a difference.
Do you have a block heater? That's the fastest way to warm it up. Putting in a Webasto diesel fired coolant heater would keep it warm if electricity was not available.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13