Yes - and the oil is very viscous when it is cold so it tends to drag the fan initially.

It all makes sense now lol

@@MrKnutriis Particularly more noticeable on a colder day vs warmer ambient temp day.

Fans not moving on car

I want to change this oil to make it strong did u try it i have 525 tds e39

@@aminecatalyseur8281 the fan clutch is sealed, no way to change the fluid inside. my original fan is still working good and it has 190k miles. a new one is cheap, it's best to buy a new one if yours goes bad

@@busterscrugs really thank u so much..

e39 owner here also lol

Your BMW can drive just fine without the fan as long your electric fan for the radiator works.

What kind of car uses a viscous fan clutch that only costs $25? I'm looking at around $400 for one for my 2003 Nissan Patrol.

@@GarySchiltz factory Nissan parts are ridiculous. Last one I bought for my keep was $25 at O'Reilly. Lol

@@GarySchiltz if your still looking to buy one check rockauto they usually have the cheapest prices. I buy all my parts from them

@@GarySchiltz thats ridiculous

@@GarySchiltz I just purchased and installed a brand new water pump and fan clutch assembly on my 1995 Nissan D21 for $48 brand new lol

I actually did the reverse as my fan clutch failed lol. Initially didn’t set out to remove the serpentine belt-driven fan but after replacing the water pump, radiator, hoses… and not bothering to put the mechanical fan back on, I noticed a 40+ miles increase when running without a fan. At first I thought this is impossible, a 10% increase in MPG just by removing a 15lbs fan?? I kept driving for almost a year without a fan and consistently got at least 40 more miles per tank which has a 400 mile range, sometimes as high as 45 additional miles. Now that it’s summer in TX and I can no longer drive without a fan without the motor running very hot borderline overheat, I ended up putting in a dual electric SPAL fan setup. I was a lot of work because you have to make custom mounting brackets and run wiring.. but it gets better gas mileage and is kinda cool to have an older truck with e-fans.

Changed mind 3 time and each time freon is released NO A/C 😢

They always runs the fan some but gradually engages as they warm up.

there's always some rotation just not at full speed.

😂

*Sprinter owners look over suspiciously*

Had one fail recently on my 2005 Ram 5.7. The problem presented as a high pitched whistle of all things, when the fan was supposed to engage. Took months to figure out after replacing the EGR, PCV, water pump, with no luck. Replaced the fan clutch with the water pump (and the radiator after nicking it.. oops) and voila! Noise gone and I can clearly hear the fan engage and disengage. It's actually a pleasure to hear the fan come on and off as it's a more aggressive pitch die to tow package. Also, the truck roars for a second when I start it as the fan spins before it disengages.

Based on this video: kzfaq.info/get/bejne/hMV3ntiFzLDWY6s.html Looks like the bimetal plate links to a piece of sheet metal that acts like a piston to suck the fluid back in. OR what I was thinking - the drive side has a specific geometry that acts as a pump all the time. so that's two possible solutions.

@@ddjohnson9717 The fins in the clutch act as a pump overcoming the centrifugal force - pumping the oil back. The bimetal thermostat is opening and closing the oil entering the clutch and gets pumped back from turning. If it gets warm enough it opens for the oil and engages the clutch and keeps it engaged until the valve is closed and the oil is pumped back into the reservoir.

@@MrKnutriis yeah so like what i though: drive side has a specific geometry that can pump oil back. The fan side will have drag, and when the valve is open oil stats flow back. Very hard balancing act it looks like. Thanks for clearing up!

a small valve

@@ddjohnson9717 Well, it's not that difficult

Salty Steel some Toyota’s had that too. Hydraulic fans are cool tech.

@@georgevinson612 I can imagine. It’s a complex system.

@@TheShamiester Yeah, I think some early '90 Camrys with the V6 had them.

@@glennfrancis9031 I know the ones we got from Japan had them as well on the diesel version.

My 1989 toyota celsior had the power steering fluid driven fan too. It worked well, 46°c outside, both air conditioners on, temperature remained optimal

Mine had gone bad and I just epoxied it in place until I could replace it.

I cut even pieces from the fan blades when i did that because the fan would run at a higher speed and take too much power. Still sounds loud. I might cut off of a bit more.

@@nairdacharles9492 Yes, or even better; replace the clutch. It's a $25 - 5 minute job - or 25 minutes if you're really slow.

true until you use the highway.

Shear plate works as impeller of a pump. Shear plate's rotation is a bit faster then its housing, so it causes fluid to flow following plate's rotation. There is a small plastic part inside the housing next to(after) return hole, obstructing the flow. As flow is blocked by the plastic part, its pressure rises and fluid goes through the return hole.

I just found that only some fan clutches have the plastic part. Others without the part seem to using fluid's viscosity itself for making the pressure.

Kelly Larsen . Better for you to play with jumping jacks than with machines.

Centrifugal...😎

@@carlosmejia5728 Centripetal. Centrifugal force is imaginary. :p

It rotates, because there is always some drag. That is normal. The real ghetto test is to start the cold engine, see if the fan will slow down in few seconds and if it does, try stopping thebfan with a rolled news paper... If it stops, it is good. If it does not. You need to replase the clutch Do it at your own risk...!

Shawn Travels The World I have did the same thing. It sounds like an airplane under the hood though

I guess if you lived in a really hot climate, that would make sense. You're gonna lose a lot of power and MPG, tho. They are pretty damn cheap, tho, or they used to be, and changing it might even take less time than your temp fix.

@@l337pwnage cool story bro.

The narrator tells us that as long as the valve is open there is a continuous circular flow from the reservoir to the outer body and back to the reservoir. Once the valve is closed the circular flow stops and the reservoir is filled up and the outer parts are emptied. It's all driven by the centripetal force from the rotating parts.

Centrifugal force makes it go from the reservoir in the center outward towards the clutches and creates a drag between them

@@wb3161 And.. now explain what the OP actually asked.

Basically, once the central valve is shut, and the remaining fluid is spun to the outer, a smaller diameter pipe runs from the outer, back to the tank on a slight angle.The remaining air is spun out replacing the fluid, pushing the remaining fluid back to the tank, not all is sent back, some remains but not enough to drive the fan.Hope this helps.

@@nssherlock4547 I said the same thing just without adding things that aren’t there. I can tell you really don’t actually know but not everyone needs to that’s why we all know different things others don’t know. I know exactly how it works I’ve been doing this for 37 years. They also use the same principle for all wheel and 4 wheel drive within the transfer case. As the clutch assembly rotates it has no choice but to spin the fluid from the center outward and that’s what pumps it back into the center it has nowhere else to go

Yeah.. almost..

No!

@@ghenkhoash2440 Tell us the difference Ghen

@@ethics3 Torque converter uses fluid kinetic to transfer power, But this one uses fluid viscosity.

@@ghenkhoash2440 elaborate please

My guess, because it is a sealed system, it cannot be repaired and must be replaced, much like a torque converter.

@@felipecardoza9967 your torque converter shares oil with the transmission and is not sealed, nor does it work like a fan clutch.

You can epoxy it shut until you can have it replaced.

@@MrKnutriis obviously once installed its sealed because if not you would leak fluids.

@@felipecardoza9967 Torque convertesr can be repaired but its not worth it (mass produced welded torque converters). Drag racing TCs can be repaired because its using a bolted design.

Wrong. this junk can fail too. they've been replaced by modern electric fans with separate sensors because of more reliability.

hostilityy it can be ,but i didn't have any problems with this kind of cooling system on the buses ,i work in the bus company on maintenance.We had some big troubles with sensors ,they often fail,here in Europe,main producer of the cooling systems and fans is a German company Behr,many trucks and buses have their parts.

Daver G very smart,but you must connect that switch by relay,because that fan need a lot of current.

I disagree quality electric fans will greatly reduce drag on your engine thus reducing heat and friction and it being it's own independent function from the motor reduces time and money spent working on your vehicle also clutch fans have a sensor it's usually connected close to your thermostat housing.

+Kike Croatia This can fail just like electric fan / sensor. Temperature sensor is extremely simple device, it should not be prone to failure and if it is prone to failure, as a cheap component the car manufacturer could put many of them for redunancy. There probably has been some manufacturing or design error or if a lot of them have been failing at your area. When done properly, it should not fail very easily . . . Indeed this is a good system too. But difficult to say what is better. Electric has some advantages in the way how the ECU can easily control it.

My father and I invented a transmission. So many barriers to introducing a breakthrough.

cool story bro.

There are ones that are just friction based and not temperature controlled. Those don't have a spring temp sensor on them.

if its engaged you should NOT be able to stop it by that method.

Therefore driving the cost from 600.00 to 2500.00

This type of coupler does no need any maintenance, the liquid inside is sealed for good.

It will a little bit just because it is still on a rotating assembly.. there is some drag to the fan even when not engaged.