Can the auxiliary fans effectively cool the m103? - PeachParts Mercedes-Benz Forum

Badinfo · #1 09-28-2002, 06:21 PM

Hey everyone, a quick question. Can the auxiliary fans on w124s safely cool the m103 12 valve engines on their own without the visco-fan? I know the auxiliarys kick in at a high temperature, but, if one was to replace the thermostat with a lower temperature unit, could one dispense with the visco fan altogether? Thanks.

JimF · #2 09-28-2002, 07:27 PM

rather than replace a thermostat. It will kick the fans in earlier.

Also I wasn't aware the VFC did anything other than take up space. Read this thread: http://www.peachparts.com/shopforum/showthread.php?threadid=41125&perpage=40&pagenumber=1

So essentially you are cooling the engine with the aux fans.

jsmith · #3 09-28-2002, 08:15 PM

and there's a flip side to that coin too. i have the cooling harness installed and it works really well. last week i replaced my thermostat with an 83C one. it works well too. in fact, so far i haven't triggered the aux fans yet. this, in spite of stop & go traffic and AC, cruising and stopping, most all the situations known to elevate temps...

Badinfo · #4 09-28-2002, 08:31 PM

I think there might be something different between the fan setup in m119 and m103 w124s. My viscous fan is always on, even when the car is just turned on, and my auxiliary fans only turn on once a month or so, when I drive the car hard, turn it off, and then come back after a few minutes in the bilstering texas sun. I want to do away with the viscous fan and just use the two electric fans to cool the car. Since I have the little 6 banger, my engine temps hardly ever go above 80. Can I safely remove the viscous fan then?

jsmith · #5 09-28-2002, 09:24 PM

the fan is always on but the viscuous fan clutch locks at an external temperature of about 107C which equates to 120C+ coolant temps. in that respect the fan clutch is next to useless. when it's not locked though, the fan still turns and provides a considerable amount of cooling. i think you can't get rid of the fan altogether, your engine would definitely overheat. there was a thread recently on converting to electric cooling fans you may want to check that out...

pmizell · #6 09-28-2002, 10:22 PM

Sorry to interrupt this thread but may I ask where you bought the 83deg thermostat please? Also, my 103 engine heats severely after being shut down (from about 90 to 110) on occasions. Is this normal? B.I., did you say your aux fans run while your 300E is shut off?

TIA

Badinfo · #7 09-28-2002, 11:51 PM

hey, pmizell, my fans don't turn on when the car is off, I kinda wish they did and that the coolant would cycle through the system... but unfortunetaly it doesn't. Everyone else, thanks for your help, I was looking at removing the viscofan as a means to gain some performance. Hot Rod did a write up on it, and they came to the conclusion that the viscofan drains more power than the alternator trying to recharge the battery. Does anyone know how many CFM the fans respectively move? Thanks!

jsmith · #8 09-29-2002, 08:35 AM

paul,

i got the 83C thermostat from kohlweiss autoparts - www.kparts.com. they had it listed as a 179F thermostat, it's actually a behr and stamped 83C.

tkamiya,

here's a report on my experiences with this thermostat:

83C

i have been stuck in stop and go traffic with it...

as to removing the fan, look for that thread about replacing the fan with electric ones. there was something about having to replace the thermostat with a reverse flow version - i forget the details but it is not that simple...

#9 09-29-2002, 09:27 AM

Not sure why someone would consider removing the primary cooling fan on a motor like the 103?

I have found over the years between owning cars and racing motorcycles, the manufacuters build them the way they do for a reason. And in large part usually know what's best (Yugo's aside).

First 124, 103 is a touring car, not a racing car, if you want to go fast purchase a c55 amg.

Second, trying to fit a round peg into a square hole.

Car weighs a bunch (4000 lbs or so), engine is mild mannered 170 hp or so.

Potential gain = imperseptibale increase in power and insignifigant gain in acceleration.
Potential loss = motor.

Simple equation.

Don't mean to be harsh but when ever you try to force a machine to be something it's not designed to be you are looking for instant never ending greif.

Joel

Mike Richards · #10 09-29-2002, 11:40 AM

Paul:

Not at all unusual for a 12 valve 103 motor to read 110C on start-up after its been driven and left to sit for a bit. Some call it heat expansion.

You now have all this heat build up and no longer have coolant circulation or air turbulance to cool things down.

After you restart the car, things should start to cool down considerably. Mine runs around 87C on the higway; occasionally around 90C if the A/C is on and it's REALLY hot outside.

In the past year I've replaced just about everything related to the cooling system and have found that a reduced coolant concentration did more for lowering operating temps than anything.

Badinfo · #11 09-29-2002, 02:04 PM

Hey everyone! 1992300e, the car weighs in at a hefty 3200 pounds not a gargantuan 4000

And, if you are willing to help, I think I have about 2k in the stock market... that plus what.. 11k for my car... if you can make up the difference, id love to drive a CLK55

The reason I posed this question is that I noticed my friends clk320 only had 1 electric fan. I really don't have much money sitting around to pull for an electric fan right now, so I was just wondering what the capabilities of the dual electrics up front were.

#12 09-29-2002, 02:07 PM

Hi,

I just hate to see people cause themselves problems (which I am good at as you will see in my next post).

I would think the gains to be minimal compared with the potential downside.

good luck,
Joel

Badinfo · #13 09-29-2002, 02:50 PM

well, the potential downside is only there if the two electric fans can't move enough air to cool the engine. I seriosly doubt they can, but if anybody had any cfm numbers it would be great...

#14 09-29-2002, 09:13 PM

I think the need to convert to electric fan(s) really depends on driving conditions and where you are located. I'm driving a 230E (M102 engine) here in Singapore and I do experience high coolant temp ONLY when I get caught in a long traffic jams on a very hot day. Coolant temp stays around 85C during daytime cruising and stays slightly over 80C at night (both with aircon on). However, temp will start to rise if the engine is to idle for an extended period with the aircon switched on. It goes as high as about 110C. My cooling system is working fine (this is despite of using parts for the local climate conditions, eg. 71C thermostat, visco fan locks at 80C instead of 105C, etc.). This is a condition caused by insufficient airflow when the vehicle is stationary or travelling at very low speeds. The visco fan simply cannot supply sufficient airflow at idle/low engine speeds. I've seen some older W124s with aftermarket electric fans and the airflow is noticeably better (despite using a smaller-sized van as compared to the original visco fan). If you take a look at the newer Mercs (at least those that I've come across), they are only using a SINGLE electric fan and the fan size is smaller than our visco fan. Yet, these cars do not experience creeping engine temp towards the red zone during extended idle periods.

IMO, the electric fan should be a suitable replacement under the above conditions.

jsmith · #15 09-29-2002, 10:18 PM

it is a reasonable conversion to do but pay attention to the negatively closed thermostat issue or you may wind up with a constantly running fan and a dead battery:

visco fan replacement

that thread never was updated and i'm not sure what ke6dcj's experience was and if he wound up installing the special thermostat.