W124 Aux fan upgrade -- Single to Dual - PeachParts Mercedes-Benz Forum

ps2cho · #1 06-19-2012, 03:18 PM

Hi guys,

This is a continuation from a prior thread.
In short, I want to improve the A/C performance while helping lower engine temps during the HOT summers here in Phoenix.

A) Anybody ever done this upgrade?
B) Will it work with the original condenser on my model?
C) Aux fan brands...Is "Metrix" any good? Its $50/each vs $125/each ACM
D) Can you replace them without removing condenser + radiator?

Much appreciated!

JamesDean · #2 06-19-2012, 05:27 PM

If I were you I would see if I could source a set from the junkyard. Replace the bearings on the fans and you should be good to go. I've got like 10 bearings I bought a while back, havent gotten around to doing it yet.

Here are the bearings that you should use. I found them in a thread a while back.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140677210093&ssPageName=ADME:L:OC:US:1123#ht_937wt_905

Here's a parts list EDIT: Just realized I used the wrong chassis, but these are the same for the 124.090 as well. Looks like dual fans was part of the 89 facelift.

From the looks of it... should be removable without having to take the condenser out.

Air&Road · #3 06-19-2012, 05:51 PM

ps,

I hope you don't think I'm picking on you or anything, but am I correct in remembering that this car was an original R12 car converted to 134a? If so, if you want to improve the performance of the a/c system, there's nothing you can do that will improve it as much as reverse converting.

You are in a TOUGH a/c environment, and a converted system is just not going to perform like an R12 system. From the results of some of your earlier posts where you gave your temperatures, it's obvious that you did a great job in the conversion, but you are REALLY handicapping yourself.

If I remember incorrectly about the conversion I apologize.

Best of luck with it.

Zulfiqar · #4 06-19-2012, 05:59 PM

If you want twin fans that can make their own tornado then get a pair of curved blade SPAL HD fans and wire them up, you can use a larger wattage resistor to step them down and you can start with the original impedance Beru part used in later cars along with separate fuses for high and low speeds, because when the two fans kick on high from a standstill the amp draw is quite large. If they are just stepping up from low then its not a problem.

anyway, I have seen a very nice system on a 88 300E, it was using its own condenser but with dual fans - the fans were being controlled by a standalone controller that sped up and slowed down the fans depending on the condenser fin temperature. The A/C performance was pretty good IMO.

ps2cho · #5 06-20-2012, 01:18 PM

No you are right, Larry and I am planning to convert back to R12, but if I am, I want to replace the compressor since its been so long as R134a and since I will have to completely remove the compressor, it seems pointless at this point to not either replace it or rebuild it. LAST thing I would want is to convert, then have either a compressor failure, or have the expensive R12 leak out next year.

Its in the works for the long run, but right now I am buying a house so I can't drop $500 to do a full system replacement and back conversion

But I figure I can boost A/C performance temporarily and of even greater amount when I back convert.

I'm reading that it may not fit on the older style condenser because of the shroud used.
What about another option of fitting one larger single fan or would two twin fans as mentioned above work better?

compu_85 · #6 06-20-2012, 04:12 PM

Looking forward to your results from the swap!

-J

hanno · #7 06-20-2012, 04:44 PM

If anyone needs them, I've got the complete dual fan set-up in a 1995 E320 (98K miles) that I'm parting. They worked perfectly. $78 includes shipping in the contUSA.

vstech · #8 06-20-2012, 06:34 PM

Quote:

Originally Posted by ps2cho

No you are right, Larry and I am planning to convert back to R12, but if I am, I want to replace the compressor since its been so long as R134a and since I will have to completely remove the compressor, it seems pointless at this point to not either replace it or rebuild it. LAST thing I would want is to convert, then have either a compressor failure, or have the expensive R12 leak out next year.

Its in the works for the long run, but right now I am buying a house so I can't drop $500 to do a full system replacement and back conversion

But I figure I can boost A/C performance temporarily and of even greater amount when I back convert.

I'm reading that it may not fit on the older style condenser because of the shroud used.
What about another option of fitting one larger single fan or would two twin fans as mentioned above work better?

Hmm.
the shroud used, on a newer 124 should fit any other year 124. I plan on pulling the fans from my gasser parts cars, and installing them on my 87 wagons.
the condenser does not need to be changed, HOWEVER, the newer condenser from 93 up were DESIGNED to operate on 134, so they are better as well... I'm just sayin...

remotemark · #9 06-20-2012, 10:10 PM

Quote:

Originally Posted by vstech

Hmm.
the shroud used, on a newer 124 should fit any other year 124. I plan on pulling the fans from my gasser parts cars, and installing them on my 87 wagons.
the condenser does not need to be changed, HOWEVER, the newer condenser from 93 up were DESIGNED to operate on 134, so they are better as well... I'm just sayin...

The problem with the newer M104 condenser on the M103 single fan models is that the ac hose is different and will need to be replaced. Because of the different sized and placed air intake apparatus, the hose can not be routed as it is on the later models and the fuel chiller cannot be connected. I've never tried to do it with the 90 to 92 M103 W124 sedans' version of the condenser, so that may work with the older style hose.

Hit Man X · #10 06-20-2012, 11:33 PM

On the W126 at least, the dual fan mounts are different on the condenser... meaning the late condenser only works with the dual fans.

Hope it helps.

BTW, big issue is the M103 cars have a puny fan blade so low speed airflow over the condenser is comical at best. Yes, even the 'updated' fan is crap. Compare that fan blade to the BMW M30 fan from an E32 or E34 and you will see the difference.

I tried to fit my SDL's fan blade and while it bolted up, the blades are pitched the wrong direction. I looked at it forever and could not find a simple retrofit sadly. This alone would make a huge difference on the M103 cars as they have a puny radiator too.

lsmalley · #11 06-21-2012, 04:44 AM

Just thought I'd add my 2¢, I live where the climate is triple digits and my a/c was converted to r134 and I did have problems with cooling at first (which turned out to be my heater valve not closing off coolant). I have since then bypassed my heater core and and added a resistor, recently to turn my aux fans on high around 90°C and my a/c gets around -50°F. It was getting around that cold once I bypassed my heater core last march. I only added the resistor because I noticed my car ran hot with the a/c on. Before converting back to r12, I would definitely try to make sure there is no coolant running to heater core and make sure your refrigerant is at the proper level. I added the refrigerant that is sold at autozone with the polar bear on it and just used the gauge it comes with. it took all but a few minutes.

Zulfiqar · #12 06-21-2012, 10:57 AM

Quote:

Originally Posted by Hit Man X

On the W126 at least, the dual fan mounts are different on the condenser... meaning the late condenser only works with the dual fans.

Hope it helps.

BTW, big issue is the M103 cars have a puny fan blade so low speed airflow over the condenser is comical at best. Yes, even the 'updated' fan is crap. Compare that fan blade to the BMW M30 fan from an E32 or E34 and you will see the difference.

I tried to fit my SDL's fan blade and while it bolted up, the blades are pitched the wrong direction. I looked at it forever and could not find a simple retrofit sadly. This alone would make a huge difference on the M103 cars as they have a puny radiator too.

yep - them BMW fan blades pull a great lot of air.. and yes the 103 fan blade looks cartoonish to be a fan blade for a large engine.

ps2cho · #13 06-21-2012, 03:17 PM

Today from engine cold 104F, freeway vent temps were 50F after 15mile drive...

BUT 2hrs later still 104F ambient....15mile drive back home, Engine HOT, freeway vent temps were 60F, and once at the stop light, it was at 70F from vents.

That is with Aux fan running on high.

As you can see, the issue seems to be that the condenser cannot shed the heat once its warm! I see the only way to get decent vent temps is doing a full upgrade along with back converting to r12.

Hitman you said the fuel cooler cannot be used? Did they remove it from the later models?

Air&Road · #14 06-21-2012, 03:39 PM

Yeah ps, unfortunately you're dealing with some extremes there. Sounds like the engine compartment is hopelessly heat soaked at that point.

Just curious, does this car still have the belly pan? What is the condition of the radiator?

With a super high ambient like that, there's no room for even the slightest variable. A radiator that is even off of max efficiency by 10% would be playing into the equation. If the flow across the radiator were even a little bit blocked by debris or bent fins, it would play into this situation.

You're just operating at the extreme end of spectrum. In about a week I will be dealing with an ambient pretty close to that. We expect to see triple digits middle of next week and still have some humidity hanging around to go with it.

Thanks for keeping us informed on all this.

ps2cho · #15 06-21-2012, 03:42 PM

Exactly its just heatsoaked and cannot rid of anything at all.
I installed the belly pan recently for the first time...but the difference was negligible.

Do you think doing the upgrade and back conversion is worth it, or will it seldom make a difference other than whats in my wallet?

My girlfriends CLK320 A/C is just no comparison to mine...in 2-3 minutes hot or cold, the cabin temperature is nice

and she doesn't even have aux fans on the front. Just one large fan on the engine which looks like its freewheeling most of the time anyway.

What would be good, is to have someone who lives in my climate who HAS a late W124 ('92-'95) with the upgrades I am looking for and for them to share how theirs acts in the climate I am faced with.