fan clutch?
 

Is there a way I can test whether my fan clutch is working properly? I am worried that the clutch may not be engaging and so while I am in gear a red light the fan spins at a low speed, and thus not suffuciently cooling the car. I am ready to buy a radiator but I dont want to just start replacing parts, hoping one of them may stop my overheating problem.

What car?

Start with the simple things. Put in a new radiator cap. If the cooling system is losing pressure through the cap it will overheat. with the car running and hot take a towel and hold taught between your hands and try to stop the fan from turning. If the fan clutch is working it'll take some effort to get it to stop. Search for fan clutch.

While doing some major work on my car, I thought I would replace the overflow tank cap. The new one was really tight. So tight, it loosed the crimped metal top of my overflow tank. This is now bubbling and seeping when the car is hot and it's running 5 degrees hotter than it did before. This is a sneaky problem, and I don't see any practical, permanent way to fix it short of getting a new bottle (which I did, $60).

Maybe I should have left well enough alone!

A mechanic told me this trick. Get an old radiator hose (I used a rolled up towel). Start your car. Let it warm up. At idle, stick the hose gently into the fan. If it stops easily, it's bad. BE CAREFUL if you ty this.
Mine stopped VERY EASILY & took about 30 seconds to come back up to speed. I put a new one on (4 bolts) and my problem is solved (temp was creeping up when I stopped at 3 or 4 red lights in a row).

The clutch in my vehicle is really goofy. When cold, it stiffens up fairly well. When hot, it free-wheels very easily. I just received a new fan clutch yesterday from Phil at Fastlane (best price around). I'm going to put it in this weekend. The V12 ran VERY hot last summer. I swear you could melt lead on the intake manifold. This should bring it down to acceptable levels.

First of all, sorry. The car is a 190e 2.6 1990.

I have read on another forum, that an indivdual injected some sort of silicon into the clutch to bring it back to life. I have no idea as to the inner workings of the fan clutch. But jamming a towel into the fan seems dangerous. Im just worried that it wont stop and suck in the towel with my hand attached to it. ????

thx

I have replenished my clutch twice now, but the correct silicon fluid should be used, 10,000CST at a minimum. If it's not been filled with silicon it's a no go!

Temperature shouldn't make much difference to the viscosity - if it's got silicon in. But the fluid will take a little while to return to chamber one after being driven for a while, once in chamber 1 it should feel stiff again.

Here's the test:

1. Do the fan blades resist turning after the cars sat for 15 minutes or so?
2. Do you hear a 'roar' from the engine at start
3. Can you hear a roar when the fan cuts in at around 90dec water temp?

If no to any of the above then it's either been refilled with incorrect fluid or the fluid has leaked away again.

Remember, why did it need refilling - I can tell you - the poxy thing's worn out! That's why I've had to refill mine twice. Only solution is to buy a new one.

Talking of buying....

Does any of you friendly US guys want to do me a favor and find out the price for a Sachs Part No:2100 015 031 is from the US

Would be REALLY appreciated.

Cheers
Lea

366 us for the fan clutch

Hi Lee

366USD - that's not too bad but now, what's the best way of avoiding duty?

Any more offers?????

Cheers...

I am not offering..... that's the price from a parts house in Arizona...usually best price in the states.....

"Can you hear a roar when the fan cuts in at around 90dec water temp"

I dont quite understand....The engine fan is always on....As i understand, it never stops. The electric fans on the otherhand do kick in at around 95 degrees. But they dont make a difference, the temperature pretty much stays the same and if I continue to stay in gear and crawl in traffic the temperature rises and rises. I havnt taken the risk of seeing what happens if it keeps rising, because I have already dealt with the coolant boiling over out of the expansion tank.

I had read on another forum that the engine fan spins at different speeds depending on engine RPM. And the "fan clutch" apparently controls whether the fan spins correctly, according to the engine rpms.

Also today while I was in some slow traffic the temp rised to about 100 degrees, then as I pulled over to a parking lot, I reved the engine to about 3500 rpms slowly, this drastically brought the temp down within a second or two. In front of my eyes I could see the needle drop to about 85 degrees.

The viscous fan clutch keys off radiator exit air temperature. At low radiator exit air temperature the fan clutch is "loose" and the clutch will slip when the engine is revved, so the fan won't rotate at more than about 1000 revs. At about 100C coolant temperature in mild to hot weather the radiator exit air is hot enough to "tighten" the clutch and the fan will spin up to higher revs with the engine, and you should be able to hear "fan roar" above about 2000.

You need to understand that the engine driven fan speed keys off radiator air temperature due to the viscous clutch' reaction to radiator exit air temperature. It will never turn faster than engine speed, but unless the radiator air exit temperature is high enough to tighten the clutch it will usually turn slower than engine speed.

You can also check under the hood. At 80-90C coolant temperature rev it up to 2000 and feel the air flow - probably not much. Let it idle until the temp hits 100 C then rev it up and you should feel much higher air flow and hear more fan noise.

Another test is to spin the fan with your finger when the engine is off and cold or cool. It should turn with little resistance. Try the test again when the engine is at 100C or better. Shut the engine down and turn the fan with your fingers. It should offer much more resistance.

It looks like you performed the "flow test" and your results indicate that the fan is probably operating properly.

In hot weather stop and go driving it is normal for the coolant temperature to stabilize in the range of 100-105C. Once you get up to speed, such as freeway driving the temperature will usually drop to 90 in hot weather and 80 in cool to cold weather.

Duke

I think that your car has the newer type viscous fan clutch. If that's the case, it will WILL NOT ROAR when it engages. The best way to test it is as follows:

Next time your engine temperature rises above 100C, do the following:

a) With the engine idling, look closely at the rotating fan.
b) While you are looking at the Fan, get a helper to shut-off the engine.

If the fan stops turning within 1-2 revolutions than its OK. If it free spins for a long time than it needs to be replaced.

Phil

Guys all this information is very very helpful, I will try all of these suggestions in the morning.

Thank you so much.