Viscous Fan Clutch Replacement

[gsxr]

My E420's always ran very much as shown above with a good fan clutch, even in 90-100F ambients with AC on they would rarely exceed 95C.

All my 500's tend to run warmer, some more than others, but always below the 100C mark unless it's Sahara-level ambients.

 

[clarkz71]

Yes, like we discussed before.

Even in the summer, 95° it shows the same temp.

This summer I'll post another (better quality) pic of the readings.

This M119 actually runs cooler then my old E420. Original radiator as well.

My 119.985 project is on hold right now, I'm working on the brake project.

 

[clarkz71]

My E420's always ran very much as shown above with a good fan clutch, even in 90-100F ambients with AC on they would rarely exceed 95C.

All my 500's tend to run warmer, some more than others, but always below the 100C mark unless it's Sahara-level ambients.

That always makes me wonder, with the 93-95 034 being 11:1 compression
and the 036 being 10:1 you would think "they" would be the cooler running engines.

 

[gerryvz]

My M117s run notably cooler than my M104 and my M119. Both the later engines will get up to 110C on hot days, sitting at stoplights, but really not above that. 95-100C temps are normal on hot days when in motion.

The M117s only hit 95C if I'm doing 80MPH or higher on the freeway, and will hit 100-102C if sitting for a long time at a stoplight, with the A/C on.

Replacing the radiator last summer on the E500 with a new Nissens unit had no bearing whatsoever on the temps of the M119.

Replacing the water pump on the E320 a few years ago also had no bearing whatsoever on the running temps of the M104. Replacing the thermostat with a new Behr unit a few weeks ago as part of the top-end rebuild also had no bearing on the running temps.

Both of those motors just plain run hot. During this cold winter we had here in Texas, much like Portland weather, neither car ran above 90C whatsoever.

Cheers,
Gerry

 

[gsxr]

That always makes me wonder, with the 93-95 034 being 11:1 compression
and the 036 being 10:1 you would think "they" would be the cooler running engines.

I've always thought the same thing. My theory is that something is different with the fuel map or ignition map between the two displacements, but so far I haven't been able to come up with any solid ideas as to the root cause. But, I've seen the same behavior across at least four different 500E's and three different E420's, so I know it's not my imagination.

 

[emerydc8]

Wouldn't more horsepower create more heat? The Bugatti Veyron has 10 radiators and 9:1 compression ratio. http://media.caranddriver.com/files/bugatti-veyron-164bugatti-veyron-spec-sheet.pdf

 

[clarkz71]

Replacing the water pump on the E320 a few years ago also had no bearing whatsoever on the running temps of the M104. Replacing the thermostat with a new Behr unit a few weeks ago as part of the top-end rebuild also had no bearing on the running temps.

Cheers,
Gerry

I agree, the pump was leaking on mine, but operated fine, It was only a 5° difference before and after. (85°c vs 80°c)

That was more then likely the Behr thermostat replacing the unknown age Wahler part.

Wouldn't more horsepower create more heat? The Bugatti Veyron has 10 radiators and 9:1 compression ratio. http://media.caranddriver.com/files/bugatti-veyron-164bugatti-veyron-spec-sheet.pdf

Maybe on the Autobahn at wide open throttle, but at normal speeds, it takes the same power to drive either car
70 to 80 or even 100 mph.

Compression ratio does create more heat, regardless of horspower level

The 93 034 with a 92 LH module is around 290hp, the 92 036 is 322hp.
Not a huge difference WOT

Which is why Dave & I both wonder what the reason is. The fuel map/ignition curve is a possibility.

Many M104 032 cars run 90°c normally and don't approach the hp level of either the 034 or 036

By comparison, my wife's 1995 Eldorado with a 4.6 liter Northstar engine, also 275hp
runs 92°c to 95°c normally regardless of traffic or ambient air temp.

6.3 AMG cars make over 465hp, and the run 85° to 90°c. So that's not the issue.

The Bugatti-Veyron makes 1000hp, not in the same class.

More investigation is in order.

 

[emerydc8]

Does the 036 have the same EGR circuitry as the 034? I wonder if Mercedes had to run the 036 hotter to get it past U.S. emissions with the modified cams and all.

 

[clarkz71]

Yes, pull the airfiter housing and youll see the same thing.

But you're on the right track in your thinking. Something has to be different.

The only thing different in the engine compartment is the SLS tank, and tandem pump.

 

[gerryvz]

I have yet to replace the viscous fan clutch on my .036 and will probably do that this year. It will be very interesting to see if that makes any difference on the running temps. All I can say is that in hot/humid Texas (or at least when the weather is hot/humid here) the M119, temperature-wise, is a totally different animal than it is when the ambient temperatures are 70-75F and below.

 

[clarkz71]

Fore sure, it gets hot & humid here in South Florida too.

On my 034, I dropped from a 90°c average to the current 80°c temp reading when I replaced the fan clutch.

Backed up by my MT2500 scanner, same one Dave uses. Gauge is dead on.

Summer here is 85° to 95° constantly, even at night it stays in the 80's

 

[gerryvz]

Summer here is 85° to 95° constantly, even at night it stays in the 80's

Our weather is almost the same, typical June-Oct temps are 93-98F during the day, and 80+F at night. It's rare to crack 100F in the summer in Houston, though more inland like Dallas and Austin they certainly do with regularity. The coastal on-flow air keeps us a bit cooler, but more humid.

I will check temps sometime soon with my bootlegged/cloned Chinese Star C3 DAS

 

[clarkz71]

That's a great idea, I'm sure your gauge is accurate.

Dave said all of his are spot on with his scanner.

When I did my water pump, it was in August. I was very surprised on my way home from the shop
in ambient temps in the mid 90's the gauge stayed right on 80° on the interstate doing 80mph, A/C on.

Even once off, in local traffic never passed 85°c. I was surprised.

I have to be sitting in bumper to bumper traffic for over 20 minutes to see a rise to 90° and higher, which is normal

But it's never reached a level that the high speed fans came on. Which I believe is 105°c

I think it's a combination of things though, good synthetic oil, proper coolant water mixture, good surge tank cap
fan clutch operation, radiator flow good. It's the package all in good order.

 

[samiam44]

"That always makes me wonder, with the 93-95 034 being 11:1 compression
and the 036 being 10:1 you would think "they" would be the cooler running engines."

Why would you think that? The 036 is 322 hp and the 034 is 290? So you have 30-40 hp more and an engine is what? 15% thermally efficient. Rest goes into heat(exhaust and water).

You will never see a temp gauge move until it the engine heat exceeds the maximum of the cooling system-then the temp gauge starts to climb.

Oil cooler makes a huge difference. I can tell you in stop and go traffic, if mine gets a little warm (over 100C), it cools down really quick with 40 mph+ run.


Michael

 

[clarkz71]

More compression = more heat. Diesels run on the heat of compression. (22:1)

The horsepower is not relevant in normal driving, as those numbers are at peak RPM levels.

Driving at 80 mph, the engine is not producing either of those numbers, but the compression is constant
anytime the engine is running at idle or 6000rpm.

Dave and I both are curious about the difference as we've both seen the same issue.

Oil cooler? US cars don't have one.

1994 E420 and E500 specs.
.
275 @ 5700

312 @ 5600

 

[gsxr]

samiam's car has the factory oil cooler fitted along with a 6L engine and some other goodies.

The oil cooler should help with temps while moving, but the main problem I've seen (with higher-than-desired engine temps) is at extended idle or crawling in stop & go traffic.

 

[clarkz71]

samiam's car has the factory oil cooler fitted along with a 6L engine and some other goodies.

The oil cooler should help with temps while moving, but the main problem I've seen (with higher-than-desired engine temps) is at extended idle or crawling in stop & go traffic.

Yes the stop & go is the real bitch, especially here in the summer.

Here's a dyno chart of a 1992 036 with and without nitrous best run on motor was 260.4 at 5500 rpm
at the rear wheels

At 2500 rpm and full throttle the engine is producing 120hp.

So I would think that at hwy speeds at 2500 rpm it's maybe 1/8 throttle and a lot less hp produced.

I think some members are confusing hp levels and cruising power being produced in the engine heat issue..

 

[clarkz71]

samiam's car has the factory oil cooler fitted along with a 6L engine and some other goodies

Sound like a well sorted 036

 

[samiam44]

Diesels are excess air engines. No reason to muddy waters talking apples and oranges.

. Hp is lb of fuel burnt in an engine. More fuel, more heat. Car is lowr and might have slightly different airflow w fender flares, but more heat in a system that is near max is my engineering bet.

Simple.

My car has a thermostatic aux trans cooler too.

 

[clarkz71]

I promised Gerry I would not argue with any members when I returned to the forum.

So I will bow out of this conversation.

I posted my opinion, and I'll leave it at that.

Good evening to you.

 

[8899]

I don't have enough miles on my M119 ACM clutch to be able to say anything other than it worked great out of the box after I got the shorter bolt.

Dave - you posted this back in 2011, do you still have the ACM clutch on your E500E? If so, still working as designed?

 

[clarkz71]

I installed an ACM clutch (purchased in 2009) and have been running it
from Aug 2011 to now, perfect operation including "many" trips to redline.

3 years and looking good.

That said, Dave and I both agree that current ACM quality is a question mark.

 

[8899]

That said, Dave and I both agree that current ACM quality is a question mark.

Hmmmm....made in China I suppose.

 

[clarkz71]

Not sure, the bearing is for sure, marked right on the orange dust seal

 

[gsxr]

Ditto what Clark said above. It isn't clear where the ACM is currently manufactured, but the bearing is clearly marked "China".

I removed the ACM from my E500 long ago. My primary complaint was it would not disengage at ~3500rpm like the factory Sachs/Horton. IIRC, it disengaged around 4500rpm. This caused some concern about the metal fan blade spinning faster than designed, although I've not heard of any blade failures - yet. The secondary complaint is the clutch was engaged too often, meaning it would engage by ~80C coolant temp in even moderate ambients (like, 70F). Although both "complaints" are good for airflow and cooling, they are lousy for performance (specifically, dragstrip bracket racing) and don't help fuel economy.

We race our E500E's and consistency is critical... the factory Sachs clutches will usually not engage until at least 90C, and we rarely hit those temps at the 'strip. My buddy who bought my old E420 has the ACM on that car, and he races with us occasionally... his clutch is almost always engaged at the strip, while ours are almost never engaged.

Kinda depends what your needs are, as to which clutch to buy!

 

[clarkz71]

I am lucky with mine. I hear it on a cold start and occasionally "over" 85°C

It always disengages between 3000/3500 rpm at the most.

Shows you what a roll of the dice they are.

 

[8899]

Out of curiousity I just plugged 1192000122 (OEM VFC) into the Parts.com part search and came up with a price of $652.50. Seems that Parts.com worked in this instance...

 

[gerryvz]

It does work for some parts, in some instances. But I've found that 50+% of the time it doesn't work.


Sent from my iPhone using Tapatalk

 

[Gmach]

Anybody got and dimensions for the home made tool to hold the pulley when loosening the clutch bolt ? I saw one that slips over the 4 bolts on the pulley...pretty crude but it seemed to work. Some one else modified a 60mm wrench but that is way too big for my pulley. I need to make one...thanks

 

[Glen]

Anybody got and dimensions for the home made tool to hold the pulley when loosening the clutch bolt ? I saw one that slips over the 4 bolts on the pulley...pretty crude but it seemed to work. Some one else modified a 60mm wrench but that is way too big for my pulley. I need to make one...thanks

Here's the one I made:

I don't recall the measurements but if you are building it yourself, I'm sure you can figure it out. Use 3/16" thick steel...1/4" is just a tiny bit too thick.

Btw, I installed an ACM clutch about 6 months ago and so far it's working fine.

 

[gsxr]

http://www.harborfreight.com/pulley-spinning-tool-66385.html

UPDATE 2017: Harbor Freight no longer sells the tool shown in the picture below (link above is 404).

Performance Tool p/n W87023 appears to be the same design as the old Harbor Freight item; available from various eBay sellers at $10-$20 or so:
https://www.ebay.com/sch/i.html?&_nkw=W87023

 

[DW SD]

Just a quick update...
I installed the ACM clutch from Autohaus AZ. It was $120 shipped, on sale. Thanks Dave for the suggestion of the shortened allen head wrench (specifically the length). That saved some guesswork. I also used a spanner wrench I had for my air-cooled 911 cooling fan to keep the pulley in one spot. Just grabbed the pin behind one of the bolts that mounts the pulley. Didn't need much force to break the allen head screw loose.

And I used a 1/2" long portion of allen head wrench in an 8mm open end wrench when there became too little room between the allen head bolt and the radiator. I used a piece of tape to keep it locked in the open end wrench. (see attached photos)....

One further note: I cut the old bolt down to 50mm of shaft length in lieu of buying a new fastener (yeah, I'm lazy and perhaps thrifty). I knocked off the sharp corners with my belt sander and double checked it cleanly threaded in before attempting to install. All good...

As for my results....

The clutch makes an obvious low roar when I initially start and rev the engine. It clearly has more lockup than the one I just removed.

I let the engine idle in my garage at a humid 81 degrees per the dash outside temp thermometer, which is pretty accurate. + / - 2 degrees. I also left the AC running and the engine ran stayed static at about 85C once warmed up. I think this is where the thermostat opens up. I've never had it idle at such a low temp.

Today some wiring supplies are coming from McMaster. I ordered some high temp fiberglass - impregnated wiring sleeving and high temp shrink wrap for the cable ends. I'll also use some dielectric grease on the resistor studs to protect from corrosion (hopefully). I thought about trying to buy some simple silicon boots, but didn't take the time to hunt them down...

 

[Klink]

Just a quick update...
I installed the ACM clutch from Autohaus AZ. It was $120 shipped, on sale. Thanks Dave for the suggestion of the shortened allen head wrench (specifically the length). That saved some guesswork. I also used a spanner wrench I had for my air-cooled 911 cooling fan to keep the pulley in one spot. Just grabbed the pin behind one of the bolts that mounts the pulley. Didn't need much force to break the allen head screw loose.

And I used a 1/2" long portion of allen head wrench in an 8mm open end wrench when there became too little room between the allen head bolt and the radiator. I used a piece of tape to keep it locked in the open end wrench. (see attached photos)....

One further note: I cut the old bolt down to 50mm of shaft length in lieu of buying a new fastener (yeah, I'm lazy and perhaps thrifty). I knocked off the sharp corners with my belt sander and double checked it cleanly threaded in before attempting to install. All good...

As for my results....

The clutch makes an obvious low roar when I initially start and rev the engine. It clearly has more lockup than the one I just removed.

I let the engine idle in my garage at a humid 81 degrees per the dash outside temp thermometer, which is pretty accurate. + / - 2 degrees. I also left the AC running and the engine ran stayed static at about 85C once warmed up. I think this is where the thermostat opens up. I've never had it idle at such a low temp.

Today some wiring supplies are coming from McMaster. I ordered some high temp fiberglass - impregnated wiring sleeving and high temp shrink wrap for the cable ends. I'll also use some dielectric grease on the resistor studs to protect from corrosion (hopefully). I thought about trying to buy some simple silicon boots, but didn't take the time to hunt them down...

No "dielectric" (espscially not "di-electric") grease and no boots!! The "corrosion" is a symptom not a cause. I'll explain later tonight...

 

[clarkz71]

No "dielectric" (espscially not "di-electric") grease and no boots!! The "corrosion" is a symptom not a cause. I'll explain later tonight...

Kent recommends dielectric grease

And read this, still disagree.........

I've been using it on plug boots for years, and cap boots

Those suckers are already on there tight enough

Dielectric grease[edit]

Dielectric grease is electrically insulating and does not break down when high voltage is applied. It is often applied to electrical connectors, particularly those containing rubber gaskets, as a means of lubricating and sealing rubber portions of the connector without arcing.
A common use of dielectric grease is in high-voltage connections associated with gasoline engine spark plugs. The grease is applied to the rubber boot of the plug wire. This helps the rubber boot slide onto the ceramic insulator of the plug. The grease also acts to seal the rubber boot, while at the same time preventing the rubber from becoming stuck to the ceramic.

 

[clarkz71]

Kent tune up kit, notice that tube of "stuff"

 

[gerryvz]

I have to be honest with you, I don't and have never followed any advice that I've seen Kent provide on video.

I also see that he uses Meyle and other aftermarket parts in his "kits."

While amusing to watch his videos sometimes, I don't view him as a super-credible source of MB repair information. His goal is to sell "kits" of parts, particularly to Diesel owners who are his specialty.

Cheers,
Gerry

 

[clarkz71]

The Kent reference was for Dave. A yoink

But I have & do use Dielectric grease as I described. Seriously.... long before I ever heard of Dave's Uncle

 

[Klink]

Kent recommends dielectric grease

And read this, still disagree.........

I've been using it on plug boots for years, and cap boots

Those suckers are already on there tight enough

Dielectric grease[edit]

Dielectric grease is electrically insulating and does not break down when high voltage is applied. It is often applied to electrical connectors, particularly those containing rubber gaskets, as a means of lubricating and sealing rubber portions of the connector without arcing.
A common use of dielectric grease is in high-voltage connections associated with gasoline engine spark plugs. The grease is applied to the rubber boot of the plug wire. This helps the rubber boot slide onto the ceramic insulator of the plug. The grease also acts to seal the rubber boot, while at the same time preventing the rubber from becoming stuck to the ceramic.

He was talking about the auxillary fan resistor, Clark. I'm with you and I use it on spark plugs, etc. I'll explain later...

 

[clarkz71]

He was talking about the auxillary fan resistor, Clark. I'm with you and I use it on spark plugs, etc. I'll explain later...

Ah, missed that.

My bad, I'll force choke myself...............

 

[jhodg5ck]

Anyone want to sell their old factory 119 fan clutches?

jono

 

[Klink]

Ah, missed that.

My bad, I'll force choke myself...............

Whoa! Don't be so hard on yourself, Brother!!

 

[DW SD]

Anyone want to sell their old factory 119 fan clutches?

jono

Jono,
I'll happily send you mine. The plastic shroud is broken on my old one, but if you want to pay for the shipping, it is all yours.

I don't get why it is a bad idea to insulate the terminal studs from the environment with something like du-electric grease. If it will vaporize in moments when the resistor is energized (hot), I get it.
I also understand it is electrically insulating. Wasn't going to apply it first before locking down the terminals.

Cheers,

Doug

 

[Klink]

Jono,
I'll happily send you mine. The plastic shroud is broken on my old one, but if you want to pay for the shipping, it is all yours.

I don't get why it is a bad idea to insulate the terminal studs from the environment with something like du-electric grease. If it will vaporize in moments when the resistor is energized (hot), I get it.
I also understand it is electrically insulating. Wasn't going to apply it first before locking down the terminals.

Cheers,

Doug

I said that I would comment on this "later" and I forgot all about it. And unfortunately I can't comment on it right this minute because I have to drive to work. I do have a fair amount to say about this troublesome little component and once again I am begging your forgiveness and saying that I will do it "later"...

Okay. Sorry for the overreaction on the grease, Doug. You obviously know what it's about. Present company obviously excepted, I continue to be astounded at the number of people who think the term "dielectric" somehow means "electrically friendly" when the reality is pretty much the opposite.

I would definitely not employ any kind of boot because that resistor actually gets frightfully hot, at times it will be glowing. That points up another concern that I would have about the type of grease and how much of it one actually put on the area.

The bad juju that actually happens at the terminals on the resistor tends to be misunderstood. The problem is not any kind of "corrosion". That aspect of its appearance as or after the connection fails is more symptom than cause.

Like I said, much more to follow later today, or at the worst case, tonight...

 

[kwontumspeed]

Anyone want to sell their old factory 119 fan clutches?

jono

I still have my original SACHS. LMK where to send it.

 

[jhodg5ck]

Y'all Rock!

I'll gladly cover shipping and send back something as a TY in Return!

Blue Ridge Mercedes
4142 Arcadia Industrial Circle SW
Suite B
Lilburn GA 30047

TY all kindly!!

Jono

 

[gerryvz]

When I replace my original one with the replacement factory unit I have, then I will send it along.

 

[jhodg5ck]

Ty Sir...!!!

 

[Klink]

For the promised terroristic rant regarding the auxiliary fan low speed resistor, please see this thread http://www.500eboard.com/forums/showthread.php?t=5431&page=2&p=83953#post83953, post #108. I just realized that I promised (threatened?) it here, but did it on this other related thread. If you wanted to see it but missed it, now you know why...

 

[emerydc8]

Thanks, Klink. On that note, I wanted to ask about whether doing the modification illustrated here http://k6jrf.com/MB_vfc.html that basically lifts the bi-metalic strip away from the VFC pin, causing full-time engagement, would cure a bad VFC. Mine was working when I did the mod a few years back, but I wonder now if I would know if it ever went bad since it is always locked up (at least until it disengages around 2500 RPM).

 

[Klink]

Thanks, Klink. On that note, I wanted to ask about whether doing the modification illustrated here http://k6jrf.com/MB_vfc.html that basically lifts the bi-metalic strip away from the VFC pin, causing full-time engagement, would cure a bad VFC. Mine was working when I did the mod a few years back, but I wonder now if I would know if it ever went bad since it is always locked up (at least until it disengages around 2500 RPM).

I doubt that it would contribute much to early failure. If you still hear it roaring with increasing RPM, and dropping out sometime between 2000 and 4000 RPM, then it is still working to at least some degree.

If you are talking about the Mr. Jim / Stu Ritter modification using the screw, that is just plain brutal, inelegant, and unacceptable IMO.

If you have done that one: Wake up and smell the cork!

I don't like noise, wasted energy, and too much cooling when it's not required anymore than I like too little cooling when it is needed. Later in that Mr. Jim link you posted, much more elegant solutions are discussed. If the area surrounding the front side of your fan clutch appears to be covered with fluid and / or a dust encrustation, then you are losing the silicone fluid and the clutch is in the process of failing...