Removing viscous fan to reduce engine load - Page 2 - PeachParts Mercedes-Benz Forum

m1tch · #16 04-19-2015, 09:24 AM

Thanks for the comments, I am tempted to look into using a slimline fan in the stock position where the viscous fan is. I know you can get the temperature sensor kits that go into the fins and turn on at a certain temperature automatically. There is also a positive battery terminal in the engine bay (the battery is under the rear seat) so I could easily run a 12V line to it.

I might look into upgrading the radiator anyway to a thicker race rad although need to check how the oil cooler works on this car as apparently its sometimes integrated together. Not really an issue if it is as I can get a simple oil cooler which I would look to enlarge at some point owing to looking to run a much larger turbo next year or the year after.

The temperature isn't cold but its not often that warm either, need to get the right balance between getting the engine up to temperature but still keeping it cool enough.

I might also be looking into fitting a manual override switch for the fan as when waiting for a drag run the temperature can creep up and there would then be heat soak in the engine bay and intercooler.

tjts1 · #17 04-19-2015, 10:59 AM

For a while I had 2 slim fans like this behind the radiator on the OM603. They worked very well. Now I have just one behind the radiator. They are much more powerful than the aux fans in front of the radiator.

2 Performance 12" 12 Volt Curved Blade Eletric Fan 870 CFM Radiator s Blade Kit | eBay

The radiator fin type fan switches are repurposed water heater components for the house. They are very unreliable. Your OM606 has a spare temperature switch port on the cyl head next to the coolant outlet to the top radiator hose. Theres should be a simple bolt stuck in that hole at the moment. Remove the bolt and replace it with an automotive temp switch. The thread is M14 x 1.5mm pitch. Theres several temp switches designed for BMWs that will bolt right in.
190D electric fan install- temperature switch suggestions?

good luck

m1tch · #18 04-19-2015, 11:13 AM

Quote:

Originally Posted by tjts1

For a while I had 2 slim fans like this behind the radiator on the OM603. They worked very well. Now I have just one behind the radiator. They are much more powerful than the aux fans in front of the radiator.

2 Performance 12" 12 Volt Curved Blade Eletric Fan 870 CFM Radiator s Blade Kit | eBay

The radiator fin type fan switches are repurposed water heater components for the house. They are very unreliable. Your OM606 has a spare temperature switch port on the cyl head next to the coolant outlet to the top radiator hose. Theres should be a simple bolt stuck in that hole at the moment. Remove the bolt and replace it with an automotive temp switch. The thread is M14 x 1.5mm pitch. Theres several temp switches designed for BMWs that will bolt right in.
190D electric fan install- temperature switch suggestions?

good luck

Thanks for mentioning the additional coolent outlet, I did see it when I was checking around the engine bay but wasn't sure if it was water or oil etc. Will look at getting a temperature switch and swap out the stock fan at some point.

I have seen a kit for around £15 which has a temperature probe that goes into the radiator fins with a variable temperature setup connected to a relay to then use on a slimline fan. Might just get that kit and then just use a temp sensor in the additional coolent port.

leathermang · #19 05-09-2015, 12:22 AM

Quote:

Originally Posted by funola

Don't forget the load on the viscous fan is always there while the engine is running but not so with the electric fan, which is on only when the set point of the fan switch is exceeded. The electric fan will be more efficient.

Not really.... at speed... where the forced air is coming through the radiator faster than the fan and engine rpm would be pulling it .... it provides an over running clutch effect.....
Without extremely well sealed fan shroud to radiator AND very close tolerance on the fit of the fan to the shroud.... a pusher fan is much more efficient....
I believe in having both mechanical and electric fans....MB spent billions of dollars designing and testing this system .....LOL..... I have had the front fans on my old Lincoln burn out.... and I sure needed the engine fan to keep the engine cool....

w123fanman · #20 05-09-2015, 03:14 AM

I'm working on converting my brother's w116 300SD to an electric fan set up. Installed a beefier 150 amp alternator, a Volvo electric fan, upgraded the main ground and charge cables.The grounds on older Mercedes, at least the W116 and W123, are somewhat pathetic. I have to now install a keyed relay and drill and tap a sensor bung to add a Porsche temperature switch to run high and low speed. We are also going to install a set of pusher fans from my 190E 2.6 parts car to further increase the cooling capacity as we are also installing dual parallel flow condensers to go with the Sanden compressor kit that we also installing.

This set up will cool probably just as well or better than the original set up and is much quieter. The total cost, including the upgraded alternator (which will also be used to run a decent sound system, no trunk rattling though) and the tap and drill bit that we bought which will be used on other cars, is about $270, while just a new fan clutch for a OM617 is $250. Unfortunately, the Volvo fan doesn't fit with my 190D or 190E 2.6.

As for none of this being stock: I really don't care. The install needs some cleaning up but looks pretty decent. It's not a concours car, just a nice weekender. I know Mercedes probably put a lot of thought into all of this but they sold us cars with 55 amp alternators, GM H4 compressors, Chrysler automatic climate control units, air filter housing brackets that seem to always snap, window regulators that warp, and rear seat horsehair pads that are prone to disintegrating. That's just a few of the issues on the W116. The 190E 2.6 has some of those issues fixed but has a belt tensioner design from hell. Wouldn't be so bad on the W124 or W126 with the M103 but the W201 really didn't have enough space for an I6. These cars are brilliantly engineered but have their faults. Mercedes is constantly improving parts for vehicles, sometimes even older ones. For example, Classic Center sells an improved version of the flush mount lug bolts to decrease the chance of the lug bolt snapping. I'm sure I'm not the only one here who has had to have lug bolts drilled out. I think that it is in the German spirit of these cars to improve poor designs. Th fan clutch design really isn't a poor one but it can be improved upon with some of these cars.

tjts1 · #21 05-09-2015, 11:24 AM

The easier access to the front of the engine on its own makes the efan swap worthwhile.

Chris W. · #22 05-09-2015, 01:12 PM

FWIW I have been running with no viscous drive fan for about 10 days now on my '95. I needed to get the car back on the road after my old fan lost a blade which borked my radiator. So I ordered a new rad, new fan, and 3 new hoses. Only the rad came, so I put everything back together without the fan, while waiting on the other parts and I'm running that way until I can do it all again and put the new fan and hoses in.

I have not "acid tested" the car in stop and go traffic with really hot weather, but so far I basically have not seen any difference in temp other than in one situation. That is when coming off a sustained highway drive and then driving slowly in a town with some stop and go. Then the temp will rise perhaps 3-4 degrees C, and it slowly comes back down as the engine cools after working hard on the high speed drive.

Rgds,
Chris W.
'95 E300D, 441K

m1tch · #23 05-09-2015, 01:23 PM

Quote:

Originally Posted by Chris W.

FWIW I have been running with no viscous drive fan for about 10 days now on my '95. I needed to get the car back on the road after my old fan lost a blade which borked my radiator. So I ordered a new rad, new fan, and 3 new hoses. Only the rad came, so I put everything back together without the fan, while waiting on the other parts and I'm running that way until I can do it all again and put the new fan and hoses in.

I have not "acid tested" the car in stop and go traffic with really hot weather, but so far I basically have not seen any difference in temp other than in one situation. That is when coming off a sustained highway drive and then driving slowly in a town with some stop and go. Then the temp will rise perhaps 3-4 degrees C, and it slowly comes back down as the engine cools after working hard on the high speed drive.

Rgds,
Chris W.
'95 E300D, 441K

Have you noticed any difference in how free the engine revs etc? My car will be more of a project car so won't be driven as a daily drive, will also be tempted to change the radiator out as well for something thicker meaning I might have to fit an electric fan anyway.

leathermang · #24 05-09-2015, 01:26 PM

Chriss W,
So you are running the car with the electric fans in front of the radiator still there... right ? They are connected and you are using the AC ?
There is no reason a normal condition system would have a problem with that situation..
At speed with the forced air from forward movement... you might not even need any kind of fan.... but I think the viscous fan clutch ( more fuel efficient than the bolted on 240 unit for instance ) is a worthy backup for that time when you are driving in hot weather and stop and go traffic and the electric fans or their power supply quit...
Cheap cars often do not have the back up systems we expect from these luxury cars.... and one does not want to be stranded in some places at the mercy of the conditions extant at the time....
We have had members drive half way across the United States with no electrical system ... only in the daytime of course... due to the basic mechanical design of the important functions of our diesels....

Chris W. · #25 05-09-2015, 03:25 PM

Hi Leatherman, yes, I still have the electric fans, but they have not kicked on so far. I believe they come on for two cases - one regarding the AC, and one regarding the actual coolant temp. When my fan blade hit the rad and the coolant slowly drained while I was driving I luckily happened to glance at the temperature gauge and saw it too high and I immediately pulled over - and the fans were running as they were supposed to. I'm lucky that I caught this before the engine actually overheated.

My AC is not working due to the dreaded condenser leak so the fans have not been coming on for that. But clearly in reasonable conditions you can drive without a mechanical fan if your cooling system is in good shape and you are not in the desert somewhere.

Rgds,
Chris W.

jimmydfw · #26 05-09-2015, 03:40 PM

I removed my fan and fan shroud on my '92 300d about two months ago because the fan clutch was broken. I drove it like that until earlier this week because I was too lazy to put the new Sachs fan on. However, it went on about 100x easier than the removal.

Anyhow, I drove it alot. Even drove from Texas to Missouri and back. Probably at least 3-4k miles with a mixture of in-town and highway driving. Without the fan, it would run between 80 and the next hotter notch which I guess is 100. As long as I'd stay moving, the temp was fine. I also noticed that running the a/c didn't have much affect. I suspect the the a/c being on caused the electric fans to run and it may have even helped.

Since I put the fan and shroud back on a couple of days ago, I have notice absolutely no improvement in the cooling. In fact, I think it runs hotter at highway speeds with the fan and shroud in place.

I live in Dallas (=HOT) and figure that if MB thought it needed a fan, it probably does so I'm leaving mine on. But, in my experience, it seemed perfectly happy without it.

I'll note, on the way to Missouri, I got 31.5mpg, on the way back I got 35mpg (downhill?). I haven't checked the mileage since but I seem to be right at 500 miles per tank. 31mpg or so.

leathermang · #27 05-09-2015, 04:35 PM

Quote:

Originally Posted by Chris W.

....if your cooling system is in good shape and you are not in the desert somewhere..Rgds,
Chris W.

I am much more concerned with in town stop and go traffic.... heat blazing off the asphalt.... Austin bad planning on roads...... 100 plus temperatures for months in the summer....
If you get stranded in heat like that it can even be life threatening.....

treetops · #28 05-11-2015, 09:41 PM

So I just replaced my fan clutch on E300 with a borg warner from PP and I have to say there is a good difference in engine temps. Since the weather has gotten warmer the temps would be about the top of the 8 on 80C(so 90ish) with the bad clutch. AC went to poop and only driving at 40+ for 5 minutes would bring it back down to 80.

Now, new clutch and the temps barely get above 80 in traffic on hot city streets with the AC on....so yes big difference. My only complaint is that it is loud

and there is a loss of power...not much but it is there.

I'd rather have a cooler engine and nice cold AC, which w/o the clutch I would not have.

Chris W. · #29 06-02-2015, 12:49 PM

Update. I have now "acid tested" driving without a mechanical fan. Basically a failure, although I did not take the situation to the end, i.e. an overheat condition. I had had a few situations where I came off the highway into stop and go traffic and noted the temperature rising. I figured it was as much dumping the excess heat from highway operation as the reduced cooling from no fan. Ambient was 70's - not hot.

However yesterday the temp was about 88 or so. I drove only a short distance - a few minutes operation, and pulled into bumper to bumper traffic on a highway. An accident had happened and I basically went up the on ramp at a crawl, merged, and then stopped. So no highway driving heat load to dump. And the operating temperature rose and kept rising. I did not see it plateau, but after it passed 100 I turned on the heat to dump some engine heat, and fortunately for me I passed the accident and things cooled down when traffic started to move.

So I did not reach a plateau or high enough temp for the electric fans to come on - either may have happened if the situation played out. I am going to order a fan clutch...

Rgds,
Chris W.
'95 E300D, 443K

m1tch · #30 06-02-2015, 01:06 PM

Quote:

Originally Posted by Chris W.

Update. I have now "acid tested" driving without a mechanical fan. Basically a failure, although I did not take the situation to the end, i.e. an overheat condition. I had had a few situations where I came off the highway into stop and go traffic and noted the temperature rising. I figured it was as much dumping the excess heat from highway operation as the reduced cooling from no fan. Ambient was 70's - not hot.

However yesterday the temp was about 88 or so. I drove only a short distance - a few minutes operation, and pulled into bumper to bumper traffic on a highway. An accident had happened and I basically went up the on ramp at a crawl, merged, and then stopped. So no highway driving heat load to dump. And the operating temperature rose and kept rising. I did not see it plateau, but after it passed 100 I turned on the heat to dump some engine heat, and fortunately for me I passed the accident and things cooled down when traffic started to move.

So I did not reach a plateau or high enough temp for the electric fans to come on - either may have happened if the situation played out. I am going to order a fan clutch...

Rgds,
Chris W.
'95 E300D, 443K

Thanks for this update, I am still deciding what I want to do with my setup, it seems that my thermostat must be stuck open as its only at 68c when at motorway speeds! I am looking to swap out the viscous fan AND the aux fans for a single/twin electric fan setup with a larger rad, this would also have a manual override for such situations as you describe.