Well, it does not spin freely before I start the car...and I do hear a roar when it gets hot but I thought that was electric fan kicking in at high speed...Seems to be OK based on all of the comments and feeback I've seen. It's a newer one also and acts the same as when I bought and installed it last year.

Is this with A/C on or A/C off?

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

Hi, I've been searching for info about the engine temperatures on my 89 2600 W124. They seem too high.
This thread is lots of help.

Where exactly is the electrical connection you're talking about, so I can check if it's plugged in backwards?
I can't find anywhere the auxiliary fans plug in near the fans themselves.
The only place I can find where anything plugs in and works the auxiliary fans, is the 'blue' temp sensor at the rear top of the cylinder head.
Thanks for the great forum.
I checked in the link to the CD's, it seems they run very hot.
I would still prefer if the engine ran at less than 105C.
http://www.startekinfo.com/StarTek/outside/12264/Program/Engine/103/20-0020.pdf

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1989 W124 260E

disley, since you live in australia, I am guessing your ambient temps are high like here in Arizona. Fan's don't help a whole lot for us -- flow and radiator are the top priorities.

Does your aux fans kick on at 105C and fan clutch locks?, as long as they work, concentrate on flow, pressure and radiator.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

Our summer are hot.
So while we're in our winter, which is warmer than many countries summer, I want to get through my list of obvious things to check.
I've replaced the radiator, with another Behr, and the thermostat at the same time.
I bought a K6JFR cool harness to bring the auxiliary fans on at a lower temperature. The fans don't seem to turn on any earlier.
The car still gets over 105C. The only time I see the auxiliary fans turn on, is when I turn on the A/C.
I want to know if this is the connection that is mentioned in the previous post by nestorb98. I've tried it in both positions and it seems to make no difference, I need to check the relay that's been mentioned, after that I'm out of ideas.
As there's no temps marked on the gauge between 80C and 120C, other than the dash which I assume is 100C, then I don't really know what temp it reaches.
It's never got close to 120, but has got over 110, at a guess.

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1989 W124 260E

disley, for your info.

I ran my 300TE during half last summer (hot as you would know) and up until recently with a non functioning viscous fan, relying totally on the auxiliary fans. Temperatures were always between about 85 and 107 when the fans would cut in a/c or not. There was never any question that the fans managed the cooling well although they did work hard on a hot day.

Recently I replaced the VFC and the difference is dramatic. In the three weeks since, the electric fans have not come on once and temperature is always around half way between 80 and the next hash mark (100). So, even in heavy stop start traffic with the climate control on, the temperature never gets above about 92.

Sounds like your VFC may be cactus but the switching points in the rest of the system are still working as they should.

Have a look here. \/

http://w124-zone.com/downloads/MB%20CD/W124/w124CD1/Program/Engine/103/20-0020.pdf

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1990 300TE

"24 hours in the day. 24 beers in a case. Coincidence? I don't think so."

It is same with A/C on or off. Before I start the car for the day the fan has a good bit of resistance when you try to spin it. After it runs hot and I turn engine off, if I try to spin it, it is a little stiffer but you can still turn it no problem. It doesn't spin easily but it is not fully engaging. I read online that some Viscous Clutch Fans should not be able to turn after engine runs hot and is turned off as they should turn with the engine until cooled down to a certain temperature.

Also...just thought of something. I had my engine replaced. I noticed that the bearing bracket sits closer to the engine than my older engine and bearing bracket (pulleys still line up fine) but could it be that I have the wrong style fan or clutch for the replacement engine?

benzme I don't think my viscous clutch fan is working correctly.
I never hear it make any noise, the fan barely increases in speed when the engine is revved, and when I shut the engine off when it's hot the fan will spin for a few seconds.
After reading this and other threads, these all sound like symptoms of an inoperative viscous clutch.
I checked with a local benz workshop, to replace the fan clutch and check the cooling system for other problems, the clutch is $290 and they want $150 for labour.
This seems expensive for a small part.
What do you think?

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1989 W124 260E

Where in Oz are you? I would say from what you describe there's not much doubt a new VFC is in order.

Price is about $50 over the odds if it's a Fichtel Sachs.
It's only a half hour job if you do the clutch only, but if they properly check the rest of the system and install the clutch $150 is not unreasonable.

You can get a Sachs VFC for around $230 from MB Spares in Canberra but postage is still another $15 or so and some workshops do not let customers supply their own parts. For the minor saving involved I would just get them to do it.

Plus there is the warranty issue as well. If it's a dud you just take it back and they take care of it. If you supply the part then you have to get another yourself and end up paying them three times for the same job.

Sometimes it's a no-brainer.

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1990 300TE

"24 hours in the day. 24 beers in a case. Coincidence? I don't think so."

Since it does it A/C off, I'm betting its your VFC too.

The best way to check -- engine COLD (check in morning).

Spin VFC by hand; if it spins more than 1/3rd of a turn its done.
Reason? Fluid inside is super thick at room temp like honey is, so it SHOULD be tough to turn. If its easy and spins, fluid is no longer inside the clutch, or enough has leaked out its not engaging by itself.

My FC didn't work on 260E, did the check and sure enough it spun about 3/4 of a turn. New one goes about 1/5th.

Either way though, you should hear it roar as temps increase. They are reasonably loud when engaged.

A new Febi VFC is ~$120, and installation is relatively simple with the right tool to lock it. Info here on this DIY:
http://www.w124-zone.com/articles.php?article_id=18

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

Thanks for your help everyone, this forum makes it so much easier to keep these cars running as they should.
benzme I've updated my location, I live in Sydney.

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1989 W124 260E

By hand, my VFC spins freely & spins a few rotations I might add.
But my VFC does engage when needed, should it still be replaced?

Mine is stiff when cold and doesn't roatate easily when I try to spin it. It's even stiffer after being hot and shut down but I have never heard it "roar" while driving or sitting at the light...only my electric fans. I will look into getting a new one.

Thanks

Not sure what model you own. But before you get a new one, you should either short the VFC temp switch's connector or apply 12V directly to the VFC to see if the clutch fan comes on or not 1st.

I am right in the middle of modding my cooling system. Replaced my 87c thermostat to 79c one. Replacing my dual 100/110c temp clutch/aux fan switch to a lower dual 91/99c temp switch to see if sufficient. If not, I will add engine rpm "idle" into the mix.

I think you might be talking about an electro magnetic clutch and not a viscous clutch. Not much choice with the VFC.

I would be reluctant to drop from 87 to 79c. Most Mercedes I am familiar with are designed to run best at around 87 plus. Unless you reside around South Hades.

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1990 300TE

"24 hours in the day. 24 beers in a case. Coincidence? I don't think so."