R.Pires

Hi,

My car has developed a behaviour that, after searching and reading a lot about the possibilities, I think I narrowed it down to the fan clutch needing rehab, with the famous Toyota silicone oil.
No matter the outside temperature, when driving on highway or a reasonable speed the temperature indicator stays a hair above the first white line.
When idling or in slow traffic, not immediately, but fast, it goes to the last white line.
Returning to highway and the needle returns to the first white line.
It is not really overheating (yet…) because the electrical fans never engage, and I know they are ok, but there is a big jump in temperature.
What do you guys think; I’m in the right direction with the fan clutch?
I know that if the seals are shoot, I can fill it to the max and next day it is all out again, but I would like to try it before buying a €400 new clutch!
By the way, is there other options besides the Toyota silicone oil, I’ve been searching around and here in Europe I think I’m going to have a big problem finding it…
Thanks in advance for your help and opinions!

Regards

PS: Coolant level is been always correct, no signs of leaking anywhere, no marks on the floor or around water pump.

Don Ashe

Instead of the Toyota oil, you can find a radio control model shop and get some silicone differential fluid. Same stuff, better availability, lower prices.
HTH,
-Don

R.Pires

Thanks for the excellent tip
By the way, the Toyota oil,, I think for what I read has 3 different grades, the radio control oil has a lot more.
What will be the correct one, or at least the most aproximate of the original?
Thanks.

Jetdriver69

My fan clutch was going out also. When I pulled the motor for a rebuild, I dumped the air pump, fan clutch and electric aux fan for a conversion kit from FFDynamics on ebay. I know, I know ebay. But their product is pretty high quality components, it was simple to install and works very well. It keeps the coolant temp way below the old "normal" of closer to the second white line than the middle. I think I paid $275 delivered. They have a two fan 3500 cfm or a single 4000 cfm set up. I got the "Texas" recommended single fan that draws 18 amps compared to the 25 amp draw of the aux electric fan. Cheers!

jpitman2

Go electric is the answer - many options. But it sounds like you are on the right track - simialr to my experiences. If you tryu to fix the viscous coupling, push the silicon in with a small syringe, while the body of the clutch is warmed and turned. Mine spat all the stuff out pretty quickly. A modified Land Rover clutch and bigger fans did OK for a while, but now have a 2 x 11" SPAL fan assembly in place.
jp 83 Euro S AT 55k - whats you r chassis no - 840812 here.

Landseer

My opinion is that you've dialed-in exactly on your car's temp issue. Fan.

Try the refill.

I used the Toyota fluid that was thickest, I think 10,000 cps viscosity.

Use something close to that, what do you have to loose?

I had several root causes to hot-running. Fan refill made huge difference (even before the injector change noted below) and still holds fluid and works today, 35,000 miles later.

Turned out that the car I was working on also had some crusty injectors causing extreme lean/hot running. (car sat for 10 years prior). Once we swapped injectors, and ever since, the fan has held temp down to the first white line steadily in stop go traffic. Big win.

https://rennlist.com/forums/928-foru...n-re-fill.html


I have another car, in the avatar, that Jadz 928 converted to electric fan years ago. But the fan is a little small, so car runs a little warm in traffic.
Plan this winter during maintenance is to re-fit a viscous fan instead (I have a spare). My solution is mainly driven by economy though.

R.Pires

Hi,
Thanks for your answers and help
I think I will try the simpler and less expensive option first, try to refill my clutch.
If it doesn't hold the oil, will think of other option.
Now, let's see if I can find the Toyota stuff or anything similar...

Regards

PS: J. P., not very distant Vin numbers, mine is 840935!

Don Ashe

I used 10,000 CST.

HTH,
-Don