Viscous Fan vs Electric Fan - PeachParts Mercedes-Benz Forum

lsmalley · #1 09-20-2015, 05:42 AM

Being as obsessed with my cooling system as I've been with my lights I've decided to entertain the thought of installing an electric cooling fan and getting rid of the viscous fan. I parked my car outside all day on a 110* day then I went and sat in it and turned the a/c on with the dual fans on high. I sat idle in the same spot for about 30 mins and there was zero cooling. This has come in the wake of another forum member having issues with his a/c cooling down his car. So after the 30 mins I put my foot on the gas and got the RPMs up to 2500 and I then noticed that there was some cool air coming in through the vents. Regardless of the clutch locking up or not, the fan only spins as fast as the engine and nothing more. My fan clutch is new, radiator is new, and my fan/fan clutch is even from a 300E and it works amazing when I'm driving, even if its only 15-20 mph, but at a stand still the fan is useless. What I plan on doing is either buying a retrofit electric fan if anyone has any info on this, or I will build my own. Anyone care to add or comment on this with any suggestions or advice? Thanks.

m1tch · #2 09-20-2015, 06:10 AM

I have replaced the useless aux front fans on my W210 with a high performance electric fan which is thermostatically controlled. I might remove the viscous fan at some point but the electric fan kicks in every now and then usually when stuck in traffic on the motorway.

If you get worried about the cooling at any point and need to dump some heat (say if the temp was getting way too hot), max out the heater to fully hot and perhaps change the air direction to your feet so you don't roast. The heater matrix will act as another radiator with fast moving electric fan.

lsmalley · #3 09-20-2015, 07:43 AM

Quote:

Originally Posted by m1tch

I have replaced the useless aux front fans on my W210 with a high performance electric fan which is thermostatically controlled. I might remove the viscous fan at some point but the electric fan kicks in every now and then usually when stuck in traffic on the motorway.

If you get worried about the cooling at any point and need to dump some heat (say if the temp was getting way too hot), max out the heater to fully hot and perhaps change the air direction to your feet so you don't roast. The heater matrix will act as another radiator with fast moving electric fan.

Not worried so much about the cooling as I am the a/c. My cooling is just fine engine temp wise. This is strictly for the a/c. All components work as they should, even have a manual switch for both high/low speed aux fans with manual water cooler. This is not a clogged condenser, stuck expansion valve, low freon charge, etc, etc. I just need to upgrade the fan. As mentioned, sitting at a stop idling at about 650-750 RPM whether engaged or not, the fan is pretty much useless. 110* at a stop with a/c and high speed fans on the temp at the vent doesn't get cold unless I pit the car in N and hold the RPMs at 1500-2500 forcing the fan to turn faster and pull more air to help cool the condenser.

I thought the dual fans on the W210 were electric. Isn't there a motor that controls one, but the other is connected by a belt independent of the engine belt?

anziani · #4 09-21-2015, 12:25 PM

Ismalley, you and I both live in the Palm Springs area. I believe you drive a 190E. I have lived in the desert for 15 years and have owned 5 different Mercedes, including a 190E. The AC didn't improve until I bought a '97 CL500 and then a '97 CL600. I can sit and idle in 110F with the AC on almost indefinitely with ice cold air out of the vents. I hate to say it but the earlier Benz AC units were not up to snuff. Maybe an electric fan will help but if I remember correctly the dual fans should come on when the AC is "on".
Anziani
'97 CL600 51K

lsmalley · #5 09-21-2015, 07:22 PM

Lol @ ac didn't improve until you bought the CL. That's a good one. My dual fans are manual control for high and low speed, in fact the way I have it wired up, the ac won't turn on unless the fans are turned on. I'm actually looking to buy a BMW 7 series. Hopefully the purchase of a new vehicle will solve my ac performance problem as well.

Hit Man X · #6 09-21-2015, 11:20 PM

Is your fan clutch a Sachs? They are the only ones that work on these cars, the Behr sold are garbage. I have the same Sachs on the 300SEL.

See if you can wedge a single e-fan in there, I was able to just barely stuff a single 16" Spal on the 300E... but now with the A/C on, the belt squeals as the tensioner is bad on it. HA So now it has a clutched fan again. The Spal pulls only 18A on high.

While I was testing it, I had the aux fan on low (per normal HVAC operation) and the Spal on low (wired with a resistor for low)... I actually had cold air coming from the vents at idle! This was with fresh HVAC box pods and crappy 134A. As you found out, the fan blade is the problem on the M103 cars as it simply does not move enough air at idle/low engine speeds. Obviously, my temps would have been cooler on R12.

Compare M103 fan blade to the similar era V8 cars and you will see a stark difference. The 560 drops right off as does the SDL, SD did decent until I tried the V8 fan. Then presto, dropped right off. I tried finding a suitable replacement but failed as the blade pitch is reversed on the M103.

Even if you have the Spal wired for high speed only operation, I am sure it will be fine. I chose to wire up for low speed AC trigger, like most factory equipped e-fan vehicles, unless the coolant temp creeps too far. Then it trips to high speed.

lsmalley · #7 09-22-2015, 02:04 AM

I have the 120A alternator upgrade. So will a 16 inch fit on a 190E 2.6? What is the best a fan to get that will fit? I need something that will really move air at idle. I want something like a wind tunnel

Hirnbeiss · #8 09-22-2015, 06:26 AM

The fan clutch is supposed to engage at idle, not 15-20 mph. I went with a Meyle and I knew it was wokring right because of the strong whoosh sound of the fan when coming off idle.

lsmalley · #9 09-22-2015, 11:16 AM

Quote:

Originally Posted by Hirnbeiss

The fan clutch is supposed to engage at idle, not 15-20 mph. I went with a Meyle and I knew it was wokring right because of the strong whoosh sound of the fan when coming off idle.

I know the fan clutch is supposed to engage, but it still doesn't change the fact that the fan only turns as fast as the engine. There is nothing wrong with my fan clutch or my aux fans, but where I'm at if I want that fan to help cool the condenser enough to blow cold air through the vents while sitting, then I need that fan to spin at least 1500 - 2000 RPM because that's what I had to has it to in order to feel the cool air come out without moving.

greazzer · #10 09-22-2015, 11:23 AM

I don't know if you have room or not, but I swapped out my OEM radiator for an all aluminum 3" from "Be Cool" and I do not need to run any fan and I live in sunny Columbia, S.C., which is a screen door to hell in the summers and my car does not go over 80C, even sitting in traffic for a while. I do plan on going to an electric fan real soon, but it has nothing to do with "cooling" issues.

anziani · #11 09-22-2015, 12:11 PM

Ismalley, I think it is the newer Mercedes ("97") and not the model. My wife's '95 E420 was a big improvement over our first 300E. Just a observation.
Anziani

Hirnbeiss · #12 09-22-2015, 12:25 PM

If your fans are working as designed, then the AC should be able to cool the car at idle. There's not much different between your car's AC and a Buick's. If you're getting no cooling effect at idle, something is wrong (like a 25 year-old condenser? https://www.youtube.com/watch?v=r_em9lm69HQ, ancient receiver/drier?). I would get it checked out and flushed recharged before adding more fannage.
And yes, I used to have a W201, with always adequate AC, in the swelterpit that is SEC country.

Hit Man X · #13 09-22-2015, 08:25 PM

Quote:

Originally Posted by lsmalley

I have the 120A alternator upgrade. So will a 16 inch fit on a 190E 2.6? What is the best a fan to get that will fit? I need something that will really move air at idle. I want something like a wind tunnel

Depends what size radiator you have in there. The 300E and 300SEL are similar in core size, roughly 20x20 so it does fit. Offset. I was able to slip it between the fan clutch pulley and the water pump pulley. It was TIGHT but fit.

Spal's 30102049 is what fit my application. It moves a pile of air on full speed. WAY more than a puny M103 fan and locked clutch will at idle.

Airflow over the condenser to dissipate the heat is what will make it cold... a big reason why 134A conversions suck at idle in these cars. No airflow to drop vent temps but they do decent down the road.

If it does not work for you, you can complain to me.

lsmalley · #14 09-22-2015, 08:35 PM

Condenser is maybe 4 years old, radiator is less than 2-3 years, ac components are within the last 4 months....as I've stated, all cooling and hvac components are working fine. And also, my engine temp stays pretty constant at the 85°C mark. I'm almost positive that if there was a fleet of stock w201s out here and we let them all sit at idle in the 110° heat, no humidity, no overcast, just pure desert heat, there would not be much difference between the temps. As Aziani pointed out, it's just the fact that the older cars are not up to par and he's here in the same city and has had the same issue with his older MBZ. Willv definitely look into the 16" Spal...even though 16" seems rather big. Not sure what the regular fan sizes of the w201 is, although I have the 300E fan and fan clutch in my set up now

Hit Man X · #15 09-23-2015, 12:42 AM

Bigger fans move more air.

You may end up with a pair of offset 10-12" fans, just depends how close the accessory drive is on the W201/M103 setup.

I really wish MB used a regular size radiator in the W124 300E and W126 300SEL, the smaller radiator limits ability for a larger shroud when using a clutched fan which is just plain silly. Take a look one day, a decent sized portion of the condenser is not cooled with the main engine driven fan. Not sure how this was overlooked on the prototyping of the M103/W126.

Pretty sure I am going to have Wizard Cooling make me a radiator for the 300SEL that is a standard width (like the 420/560, the SDL, etc) but M103 specific coolant hose connections so I am able to use full width e-fans. V6 Ford Contour ones should fit the bill in that area just fine as they are very slim and move a pile of air.

FWIW, I changed the 300SD over to a dual speed Volvo fan found on the mid to late 90s 960 and S90/V90 platform. They move an insane amount of air, my V90 has never used high speed during normal operation. I made a post about it in the Diesel section. It was a fairly sung fit with the five cylinder in there, but was able to squeeze in down there with a bit of room to spare. This car has a 115A alt, so can keep up with the marginal increase in charging system demand.

560 is going to receive the same setup as the SD, provided it fits, as the Behr clutch I installed is bad. It stays locked pretty much always.

Sachs for this car are $$$$$, so the Volvo fan swap makes the most sense. Better AC performance at idle, quicker warm ups, bit better economy, and a bit more power. Only positives.