Viscous Fan Clutch Replacement

[gerryvz]

Just about every independent shop I go into has and uses Meyle parts.

A number of years ago I had the front suspension on my 560SEC totally rebuilt. All chassis rubber, bushings, ball joints, etc. replaced. When I picked up the car, it immediately became apparent that I had a problem with the idler arm bushings, which had just been replaced. They were causing vibration and creaking/squeaking immediately after I picked up the car. I took the car back to the shop about a week later and asked them about it. They said that it was the only part they'd installed that wasn't MB OE -- their supplier (Worldpac) had provided them this Meyle idler arm bushing kit after they accidentally left off the OE bushing kit. They ordered a factory kit and replaced the Meyle bushings, gratis. Never had a problem since. The Meyle stuff was just, well, bad stuff from the get-go.

Cheers,
Gerry

P.S. I have heard somewhat better things about the Meyle "HD" suspension bushings (i.e. strut tower rubber) and would be willing to try this on an experimental basis. But it would be only with a lot of caution.

 

[Christian_K]

That is interesting as i have the same kit in my 500E and it was original from Meyle and then "FEBI BILSTEIN" rebranded. No issues with it. Though i never actually had to replace it, the OE one that was in was still in a very good shape.

 

[gerryvz]

I put anything that is "FEBI" in the same questionable bucket as "Meyle". While they may be somewhat better than total-crap brands such as Uroparts, they are definitely not up to OE/OEM standards. The funny thing is that Meyle does call itself an MB OEM. Probably because they make some bolts or one small piece for MB, so this gives them the ability to call their entire business an OEM.

Did you check the listing that I have of Good, OK and Bad parts vendors? It's been updated numerous times and you'll find that brands like Beru and Sachs are on the approved list, while Meyle and FEBI are MUCH lower on the quality list and are not "recommended" brands if you can help not buying them.

Cheers,
Gerry

 

[gsxr]

EDIT: Dave the pictures showed at "daparto.de" are often just examples. Beru lists this Part Number ONLY fitting for W124.036/034 and E60AMG. I don't think they made a mistake there.
The corresponding TECDOC image to that Partnumber is this:

Interesting... that looks nearly identical to the ACM or Vemo aftermarket units. Note that your catalog indicates 0 720 002 043 and the photo shows 0 720 002 044.

 

[gerryvz]

Couple of questions, Dave, as I will have to do this job before the summer hits here. Don't want to go yet another summer with my E500 not having a new clutch:

a) Do you just recommend getting the Sachs/Horton (factory) clutch over the ACM or VEMO these days, despite the triple or quadruple cost?
b) Can one buy the Sachs/Horton clutches on the aftermarket for less (like a Bosch fuel pump) than they cost from MB? Or is it parts.com only?

If the ACM stuff is now being made in China, I'm more hesitant than ever to use it.

Thanks
Gerry


:-o UPDATE: Looks like I just answered my own Question #2. The Sachs clutch is available at AutohausAZ (indicated in their online catalog) but it's $607 ! as opposed to $537.60 for the factory part via parts.com.

 

[gsxr]

Based on my experiments... the ACM and Vemo both engage the fan more often than the OE Sachs/Horton clutch. The stocker may not do much until the engine temp is 90-100C, while the ACM or Vemo may engage at lower temps. Remember this is affected by ambient temps as well, so at 30F ambient and 85C engine, it may not engage... while at 90F ambient and 85C engine, it may engage (especially if the AC is on). The AC has a big effect, with AC on the clutch is much more likely to engage, as heat from the condenser affects the bimetal strip on the clutch.

That said, the ACM disenagages at a higher RPM than OE (ACM is approx 4000-4500, OE is approx 3500), which I'm not crazy about. The Vemo never did disengage in summertime temps (did not test in winter) so I did NOT like the Vemo at all, and probably would not use it on my cars... freaks me out to think what would happen if you spun the engine to 6000rpm and the clutch never disengaged. I've got the ACM clutch in one E420 and it's been ok so far, but I don't have a lot of time/miles on it.

The ACM will cool more than OE since it engages sooner and keeps it locked to higher RPM's. So for max cooling, ACM might be preferable. For peak power the OE would be preferred since it doesn't engage as much, but also allows temps to go higher. Every OE/OEM clutch I have works just a little different which is maddening, as it's not clear exactly how it should function. I haven't heard of any catastrophic failures with the ACM clutches yet. I'd use one with caution. On the flip side I've tested two new OEM Sachs that did not fully engage even in summer, not sure if they were duds (on shelf for long time), or not. I haven't yet shelled out for a new OE Horton to compare.

 

[Jelmer]

I, for one, can support Dave in that the VEMO/Vebi whatever does not disengage until revved > 5k rpm. Strangely enough the one that I had also engaged with a cold engine, so I was roaring through the neighborhood waking everyone up. The Sachs I have now seems to engage only when the needle reaches the 100C mark, though. Might be related to the above ambient temp stuff, or just my cooling system that's completely wonky ;-)

 

[gsxr]

Oh yeah - the ACM is engaged after a cold start for a few minutes, or until the engine is revved to 3k-4k (approx), at which point it disengages and will not re-engage until the bimetal strip gets hot enough to be triggered. I'm ok with this, you can hear the fan roaring, but it's not obtrusive and kinda lets you know it's still working, lol. The reason is the silicone fluid inside the clutch has to pass from one chamber into another and it takes a bit for this to occur when cold. The OE clutch does the same thing but it happens much more quickly (i.e., seconds instead of minutes), so you don't get the minute or two of roaring when cold.

 

[Christian_K]

My AVA-Cooling clutch in the C36 behaves this way:
Engine cold, clutch is enganged for around 2-3minutes of driving, then slowly disengages. Engages regularly below 100°C, Probably already at around 95-97°C (temp gauge very close to 100°C mark) which i quite like. When engaged it disengages at higher RPM (above 4000RPM). For the very low price i'm satisfied so far.

Ahh and ifound 2 Pics i made as i was replacing it:

 

[Jelmer]

Oi, great timing that you posted in this thread again. I was about to shove the viscous fan up my mechanic's.... errr... deskdrawer, since I found that it only sometimes engages, but then it's near the 100C mark. You guys say that's OK?

I'll disconnect the Cool Harness one of these days, since the aux fans switch on earlier than the viscous fan does, so it seems.

Somewhere, I'm just very scared my screwed up cooling system, the plenty work that's been done on it, etc, have had a bad effect on the brand new Sachs, and that it's broken somehow :-/

 

[Christian_K]

There is AFAIK no official Data available as to when exactly the Viscous clutches should fully engage... I only know this: Between 80°C and 89°C cooling-fluid is the normal Operating Temperature of the M119.
Even though all new Thermostates bought at MB are saying "80°C", i never saw the gauge stick at 80°C in any 500E/E500 nor E420/400E, it is rather at the 89°C mark every-time. Dunno how that correlates. *Speculation*

So if the clutch engages fully around 95-100°C this is very Ok for me and was never different in other cars i've driven with viscous clutches. I think the Cool-Harness is unneeded in our European areas when you have a working viscous clutch.

 

[gsxr]

Folks, remember that the fan clutch engages based on air temperature at the clutch, not coolant temperature. This means that in cold climates, the engine temp could be 100-110° and not engage the fan clutch, even with a perfect cooling system and perfect fan clutch. This is noted in the M117 FSM, see attached PDF file, read the "Caution" note on the last page... also note that the clutch is designed to be decoupled below approx 95°C coolant temp. Click here to view the FSM detalis on the M119 clutches, please look at all five pages in the PDF file and see my embedded notes.

Side note: with the AC operating, the additional heat given off by the condenser may cause the clutch to engage even at a relatively low coolant temp (80-85°C)... yes, a LOWER coolant temp, not a HIGHER coolant temp. That's because the AC condenser is giving off heat which increases the air temp at the clutch face (BMS), even though the electric fans are usually on. I've seen this repeatedly on my cars, with the AC on the mechanical clutch may be engaged at 80°C coolant temp on a warm day (with AC), but not engaged at 90-95°C coolant temp on a cool day (no AC).

In summary... don't expect your mechanical fan clutch to always be engaged above a certain coolant temperature. But on a hot summer day with the AC operating, with coolant temps at 90-95°C or higher, in general the clutch should be engaged and pass the "roar" test to at least 3000rpm.

 

[gsxr]

Even though all new Thermostates bought at MB are saying "80°C", i never saw the gauge stick at 80°C in any 500E/E500 nor E420/400E, it is rather at the 89°C mark every-time.

The t-stat rating of 80°C usually translates into an operating temp of 82-88°C on the dash gauge (approx). My E420's tend to be closer to the 82°C mark in winter, while the 500E's tend to be closer to the 85-90°C range in winter. Both run warmer in summertime but usually not above 100°C.

I think people get freaked out at seeing the coolant temp at 100°C, but without good reason. There is nothing dangerous about that temperature. The CoolHarness and other mods all aimed at keeping the temps lower show how many people want their engine cooler, "just because". Sure, cooler is preferred, but it's usually not worth the effort to try and force that to happen. And there are drawbacks to the clutch mods and CoolHarness... increased noise, parasitic power loss, and reduced fuel economy. In very hot climates with bad traffic these mods might be desireable... but that doesn't mean that every 500E needs the same mods.

 

[Christian_K]

Thanksy very much Dave. I will check my German WIS, it it tells anything different about the RPMs or Temps regarding M119 Fan clutch.
Btw: The engagement-temperature i posted with the AVA-Cooling clutch, was based on stand-still at current outside-temps (10-15°C), because driving during these temperatures (and lower ones) it never engaged so far, as Temperature never raised above 90°C during driving so far... lets wait for the summer though ;-)

 

[Christian_K]

I just find out that ACM is really based in germany. http://www.acm-germany.de/index.html

[FONT=Arial, Helvetica, sans-serif]automotive climate-control
marketing GmbH[/FONT]
​

[FONT=Arial, Helvetica, sans-serif]Saseler Damm 7
D - 22395 Hamburg[/FONT]​

[FONT=Arial, Helvetica, sans-serif]Telefon: (+49) 40 / 600 40 45
Fax: (+49) 40 / 600 40 46
E-Mail:[FONT=Arial, Helvetica, sans-serif]kontakt@acm-germany.de[/FONT][/FONT]
​

[FONT=Arial, Helvetica, sans-serif]
[/FONT]

Strange i can't find their Products anywhere in germany. In their Webshop i couldn't find any Viscous clutches for Mercedes-Benz.

 

[gsxr]

Try this link:
http://www.acm-germany.de/acm/0759.0063.html

 

[Jelmer]

I'll try and fiddle that very good information into the wiki page. It would explain a lot. It's relatively cold here (10C), so that'll make the fan engage at higher temps. I'll keep testing!

 

[bing]

Oh yeah - the ACM is engaged after a cold start for a few minutes, or until the engine is revved to 3k-4k (approx), at which point it disengages and will not re-engage until the bimetal strip gets hot enough to be triggered. I'm ok with this, you can hear the fan roaring, but it's not obtrusive and kinda lets you know it's still working

I keep meaning to ask about this why it roars on cold start , but now "Cool Man Dave" just answered it. Didn't think it was normal. Yeah, good way to tell that it still works !

 

[Christian_K]

I keep meaning to ask about this why it roars on cold start , but now "Cool Man Dave" just answered it. Didn't think it was normal. Yeah, good way to tell that it still works !

Yes i actually like that behavior very much either

I'll try and fiddle that very good information into the wiki page. It would explain a lot. It's relatively cold here (10C), so that'll make the fan engage at higher temps. I'll keep testing!

Nice ;-)
Have you tried the engagement temperature while standing still? I've done it by switching off the heating and rev the car to 2000RPM for some minutes, then the temp-needle raised slowly and seconds later as i was revving it again, i could hear the clutch fully engaged (love that sound hahhaha)

 

[Ron500E]

"Cool Man Dave"

A moniker is born !!!!!!!!!!!!!!!

R

 

[Jelmer]

Have you tried the engagement temperature while standing still? I've done it by switching off the heating and rev the car to 2000RPM for some minutes, then the temp-needle raised slowly and seconds later as i was revving it again, i could hear the clutch fully engaged (love that sound hahhaha)

No, I haven't, yet. But that's because the silly temp gauge stays pegged at 85C when driving, only way to get it up (err... the needle, focus!) is to drive a bit on the freeway and then quickly pull into a parking place. Then it rises to 100C or above, and the aux fans switch on. But if it's not activated by coolant, I can understand why the viscous fan isn't active yet -it's still cold around the engine!

As I said, I'll remove the CH and test it for a week

 

[Jelmer]

To be honest, I don't like the Sachs clutch as much as the aftermarket ones. In my eyes, the engaging temp is higher than it should be, and it disengages too slow as well. The Febi felt as if it would engage as soon as the temperature needle moved only slightly, roaring until it's back at 85C again. The Sachs is a lazy piece that waits until it's sure it's nice and hot under the bonnet.

Yes, eventually it engages, and yes, it can roar loudly, but it only engages at 92C-95C and seems to disengage at 95C again. It also takes much more time before it actually switches on, somehow, see this:
[youtube]kRvNb4YDjr4[/youtube]

 

[gsxr]

Yes, eventually it engages, and yes, it can roar loudly, but it only engages at 92C-95C and seems to disengage at 95C again.

Yep... that is exactly how MB designed it. They basically don't want to waste power spinning the fan below approx 95°C. As long as it's engaging by ~100-105°C in warm ambient temps, you're fine.

 

[Jelmer]

That's what my conclusion is, as well, but it still feels better if it engages slightly earlier. With these margins the entire front-end of the car becomes a frying pan

I think I personally would choose another brand next time, simply because it keeps the engine just that tiny bit cooler. Dunno why, maybe I'm too anal about that bloody temp gauge, but it just kinda feels better when that needle stays pegged at one spot.

 

[Christian_K]

Have you tried to add a bottle of "water wetter" to the cooling fluid? Helps a bit and is tested in the M119 5L by Jim Forgione (hope i spelled that right).
On the other hand, i agree to you that this engagement temperatures are kind of "high"... a bit too high...
At current Temps in Germany of 22°C Daytime with full sun and no clouds and without the AC on, my Ava Cooling Fan engages hearable at around 95°C i would say... Thats in the middle between the 90°C and 100°C mark. I quite like that... If it survives this summer, i will put it in my 500E aswell...

 

[bing]

Then it rises to 100C or above, and the aux fans switch on.

As I said, I'll remove the CH and test it for a week

JB, this may not be relevant at this point and I don't want to be off topic, but the aux fan should switch on below 100c?? After all this is the idea of CH.

In this case, you might as well remove the CH as it appears to be cooling as stock to me, which is perfectly fine as Dave pointed out.

Dunno why, maybe I'm too anal

Told you didn't I ? Easy to be anal with this bloody cars!

kinda feels better when that needle stays pegged at one spot.

You won't see the Temp gauge pegged (unless it's pure highway driving) that's why the system has multi Activation/Deactivation points! At best a CH can minimize this if it's really irritating you seeing that needle moving up.

 

[Jelmer]

Ah, I forgot to mention: the CH has been off of the car for a while now. Strangely, it always activated at the middle line in the gauge, almost makes me think (no, don't hit me!) GSXR is wrong and it really *IS* 90C at that line...

Very glad it all functions as designed, indeed.

 

[gsxr]

LOL! Nope, the line between 80C and 120C really is 100C. You can verify this yourself with the HHT/SDS or any other digital scanner that communicates with MB CAN. All my M119 dash gauges read within about 1° of the temp shown on the live data stream (which are from the 4-pin temp sensor, not the 1-pin sensor used for the dash gauge).

I think mechanics like to tell customers that the line is 90C so they'll feel better and stop complaining about their car running too warm. "Oh, that line is only 90C? Well I feel much better now. Thank you, Hans!"

 

[Christian_K]

Hrhrhrhhrhrhr..... "Thank you, Hans!"

 

[bing]

LOL! Nope, the line between 80C and 120C really is 100C. You can verify this yourself with the HHT/SDS or any other digital scanner that communicates with MB CAN. All my M119 dash gauges read within about 1° of the temp shown on the live data stream (which are from the 4-pin temp sensor, not the 1-pin sensor used for the dash gauge).

I concur with Dave - spot on 1c variant when I tested mine on SDS.

I think mechanics like to tell customers that the line is 90C so they'll feel better and stop complaining about their car running too warm. "Oh, that line is only 90C? Well I feel much better now. Thank you, Hans!"

Nein, nein, Hans .. Sie sind falsch! Jetzt gehen und fragen, Klaus, schnell!

 

[MercedesBabyBenz]

Has anyone considered replacing this viscous fan with E63 electric fan yet?
If it's good enough to keep the air flow in E63 engine compartment, it should be good for our E500E's. right?
I found the fan on parts.com website and it's about $600 (part# 10 in the diagram)
http://www.parts.com/parts/2007/MERCEDES-BENZ/E63 AMG/?siteid=2&vehicleid=1433559&diagram=F356010

 

[gsxr]

Depends if it will fit... need the complete dimensions. Also, the EPC indicates "850w", which I hope is a typo, as that would indicate something like 60A current draw...! Note that it probably has a variable speed controller which might be difficult to retrofit on a 500E, even if the fan will physically fit.

Part # 211-500-18-93, superceded to 211-500-22-93

 

[195910]

Actually has control unit which is connected to the ECU. actuation and load depends on ECU parameters.
Will need to determine how actuation through 500E aux fan switch is possible. Also check C63AMG fan unit for smaller dimensions

 

[Jelmer]

Doesn't the E63 have a viscous fan? Just this single one is responsible for the AC radiator AND the normal radiator? 850W doesn't sound abnormally much for a fan that will need to move a lot of air. Agreed it'll be an insanely high current, but I doubt it'll have to supply that for a long time.

The viscous fan is actually placed in a really dumb position. It tries to suck air through the radiators, but wastes much by "leaking" around the edges, moving it about in the engine compartment instead of forcing it out, etc. With a strategically placed electric fan, you can FORCE air through the radiator, which will be much more efficient. It probably has a variable speed in dozens of steps from off to max, meaning it will turn slowly most of the time, to compensate for standing still. Remember that the driving wind our E500Es receive at 30-50kmh is also very little.

Taking out the viscous fan would also gain us some very welcome room in the engine bay. Heck, there might be room for a V12, then (without taking out the fog lamps etc and putting small radiators in).

This is definitely something I'm putting on my "if I ever get a black 500E" list

 

[MercedesBabyBenz]

btw, Jelmer, I looked in the E63 engine compartment at a dealer last week and the engine did not have a viscous fan at all. The only fan I could see was this electric fan with variable speed controlled by the Thermostat according the salesman. I could be wrong though.
I was thinking maybe we could use the signal from the coolant sensor to trigger a slower speed and the auxiliary fan signal to trigger the higher speed. What do you guys think?

 

[Jelmer]

I've been thinking about this for a bit. The circuitry needed to control a fan like that based on an analog temperature sensor (the 4-pin sensor we already have, which is very accurate) isn't complicated. However, since these newer cars carry more cpu power than is needed to fly to the moon, I doubt it's an independent circuit. I.e., most likely it's hooked into some "all knowing, all seeing" main computer thingie. You might be able to check the EPC thingie though?

I doubt you could've missed the viscous fan, if it had one, though. It's hooked up to the engine, so it's BEHIND the radiator(s), and it needs a big shroud to direct the air. I just realized it needs some (!) spacing due to possible engine movement, so it can't be made to fit exactly into an opening. Easy to see, hard to miss.

Also, the 60A current is high, and I'd say in 40C+ weather with A/C on full, the fan will indeed get near this number. Can the 500E alternator deliver that much (at idle) ?

 

[Jelmer]

Has anyone tried this procedure:
http://www.k6jrf.com/MB_vfc.html ?

And especially the last bit:

I want to report great progress. It seams like that this is the first time, in all the years I own this car, that I am able to control the temperature with the Viscous clutch.

I tested it yesterday and it works great. With about 80F ambient temperature and the AC on, in stop/go traffic, the temperature doesn’t go over 92 celsius. The fan clutch kicks in about 92C and stays there. Actually, when I stop the car with the engine running and the A/C on, after about 3 minutes it temperature goes down below 90C. I still want to test it thru the summer and I expect the temperature to go up little in hot summer days, but so far this is absolutely great result.

I used different pin (just in case I screw up) and I made the pin .015” shorter then the original one. What a difference. The clutch used to engage at 100-102C and it dropped down to 92C. This made my day. Again my friend, I want to thank you for the great information that you have on your website!

While comparing my car with 036's car, I noticed that mine runs much hotter. This is mostly due to the viscous fan, that seems to switch on very late (at standstill, nearly at 100C) and turns off quickly after that. It seems that when the entire lump of aluminum has reached 100C, it'll never get down except for driving at freeway speeds. Even when revving, the fan cuts out slightly below 100C, after which the engine temp quickly rises again.

I know it's not "bad", it just annoys me

 

[gsxr]

The flip side is, if you modify the clutch to engage at a lower temp, it ends up running even when not needed. This sucks power and reduced fuel economy, and it's noisy as well, but if you really want your engine as cool as possible, it should work. If you overdo it, the clutch will run at all times, even in cold weather, regardless of engine temp or ambient temp.

 

[Christian_K]

Now that we get close to the Summer temps of 30°C ++ here in Germany (Today we had 29°C in shadow) i somehow don't like that Ava Cooling fan a 100% anymore for the fact, that it stayed engaged the whole time when driving in Towns/Cities. Thats with AC OFF! Temps stay solid at around 90° according to the dash. On the one side thats great for the engine temps, but on the other hand its bad as the car gets a really sluggish acceleration in Towns - feels like a 4 cylinder when accelerating from low RPMs in the highest gear.
To move as quick/slick as before, i now have to put the gearshift-lever to "3" instead of "D". Before that, the Torque of the C36AMG was high enough to even accelerate perfectly when driving with the 4th gear engaged and on "E" mode in cities, at around 1200RPM at the given speed-limit (50km/h).

It only cuts out when going outside of towns/cities and driven like 2-3 kilometers. I know its good that it keeps the engine cool, but it eats significant power on my C36AMG (OK, granted i have a sensible butt dyno and having already one co-driver nets in "significant" less power for me haha).
Also i tested it today and revved the engine until ~5200RPM and the Fan stayed engaged and was freeeeeaaaaaaaaking loud/fast at that RPM. So, short in-town accelerations from traffic-light to traffic-lights is now a no-go in my C36 AMG during hot summer temps :-(

So the AVA Fan is now only 50% recommended by me. As i love to accelerate and beeing used to the Torque, high enough to quick moving the car in cities even with the 4rd gear engaged, this is bad for me. Also that it won't cut off at 5000RPM is bad, i don't want to try it higher, what if that thing brakes at 6700RPM ?

On the other hand, it engages early (at ~30°C outside temp in pure sunlight, already at around 90°C! - Notice that the stock engines Operating temp of the C36AMG is at 89°C lol) and keeps the engine cool.

 

[Jelmer]

The flip side is, if you modify the clutch to engage at a lower temp, it ends up running even when not needed. This sucks power and reduced fuel economy, and it's noisy as well, but if you really want your engine as cool as possible, it should work. If you overdo it, the clutch will run at all times, even in cold weather, regardless of engine temp or ambient temp.

The way Jim describes it, one could also change it ever-so-slightly. In that case the viscous fan would come up earlier, but would still shut off again.

Today was a warm (20C+) day but especially humid. When driving in town at 50km/h, the fan turns on and off, and the engine temp stays at 100C or even slightly above that. Bugs me to bits. (A/C was on at full power though).

Edit: at this point I'm even considering swapping the Sachs for an aftermarket one.

 

[gsxr]

Edit: at this point I'm even considering swapping the Sachs for an aftermarket one.

Another option, which I'm considering experimenting with, is using the plastic fan blade from an 119.985 engine along with an M103 fan clutch. Both parts new are much less $$$ than the 119.974 Sachs clutch (which most people think engages too late). Or, you could try the ACM 119.974 clutch.

 

[BahnStorm]

Have any of you gone the route of removing and "re-furbing" the fan clutch? As in, removing the bi-metallic strip and cleaning it properly to remove any debris/tarnish/build-up? Obviously this is a sensitive calibrated part, and build-up on it can affect its proper function.

 

[gerryvz]

I've seen threads about people refilling the clutch with new viscous fluid (I think that's even been discussed here) and such, but it seems that these "refirb" types of repairs have largely been unsuccessful. Most folks I know (myself included) have just purchased new fan clutches, either quality aftermarket or OE/MB). That would be my recommendation in any case.

Cheers,
Gerry

 

[vatc5637]

The original fan clutch on my '94 E420 no longer works. Based on this and related threads, I decided to go with the ACM fan clutch. Although I didn't source the replacement from AutohausAZ, I did use the parts # listed in this thread. I received the new part today and it appears that the design has changed significantly (photos attached). The bi-metal clip has been replaced by a different "coil" design and there is a new "mount" attached that appears to be made of hard plastic. The part came labeled appropriately and if I recall correctly, the part picture shown on the website was the same as picture included in this thread (BTW, I ordered based on the part #, not the picture).

I wanted to update this topic: 1) in case anyone else who was thinking about purchasing a new fan clutch wouldn't be surprised; and 2) to get the group's sense of whether or not this new plastic mounting piece will raise any new installation/operation issues. There is no stamping on part indicating place of manufacture.

Thanks in advance and regards to all.

(p.s. Jelmer, I came very close to ditching the fan clutch altogether and choosing to replicate your electric fan configuration but I decided to go the lower cost route and save those $$ for some other goodies I've got my eye on)

 

[gsxr]

Bad news... that clutch will not fit your 1994 E420. The clutch shown above is for the M117 engines, I believe. Definitely will not fit M119. The label is correct, the clutch is wrong... looks like a warehouse / factory error.

It should look like the photo below, note the mounting bolt goes through the center, there is no flange on the rear.

If you get the proper ACM clutch, remember you ALSO need a shorter bolt, shown here... must be OE only, the aftermarket bolt head is too large.

 

[vatc5637]

Much appreciated Dave. Will return and try to get the correct one.

 

[cwmyoung52]

GSXR is right about the bolt. I got a capscrew at my local hardware store that worked perfectly. $1.25 plus tax.

 

[midnightlsc]

A couple of years ago I installed an ACM fan clutch using the shorter bolt and it was far easier to install having more room with the thinner clutch. The ACM clutch works well at keeping the temps down as now the car runs around 85C- 90C. Hardly ever hear the electric fans coming on. With the ACM there is an increase in noise and is definitely noticeable except when cruising. Any type of slightly agressive acceleration and the fan roars. The noise is the only thing I don't like about the ACM.

Francesco
1995 E420
2000 E320

 

[e300d]

Well a bit of disaster struck.

Last night I got some time to work on my 1992 500E.

Did spark plugs and air filters. Car has been sitting and the spark plugs made a great difference!

I went to cruise around the block, came back, car idles for about 15 min. Coolant temp came up to about 90C. I was keeping my eye on it.

Went for another spin before putting her away to sleep. Bang !!! Crrrack! Clikk clikk clikkkk! And lots of smoke pouring from underneath the hood. Coolant pissing out .

Looks like the bimetal piece came off flying and took out the radiator!!!

This is aftermath:

Pic 1 - metal strip from front of fan clutch
Pic 2 - what used to be a good radiator

Essantially that metal piece came off flying and got caught bet the flan clutch and radiator and decided to carve out a nice circle in my radiator.

So what the hell?? I go give the car some TLC and she goes and kills my rad..

What is next?

I am thinking a new ACM fan clutch and a new or good used radiator

 

[Glen]

Bummer, sorry to hear. New radiators aren't that expensive, I'd get a new one.