Thread: How hot is too hot?

Originally Posted by Kevin B

I just checked mine, when I start cold the fan cannot be stopped with a paintbrush or even rolled uo newspaper but after it reaches normal opp temp tge fan can easily be stopped with a paintbrush when I let it go it takes s bit to start spinning again, does that mean mine is RS?

1993 Discovery 1 3.5l
2" Lift, Cranked HD Trailing Arms
31" Maxxis Mudders
Tons of Radios, Tons of Spotties

Kevin B,

The fan normally roars at start up, ie, it is engaged and turns as you have described, can't be stopped by a brush.

After a short period the fan disengages after it redistributes the silicone oil, at this stage you car is not up to temperature so it is ok that it does not engage and you can stop it with a brush.

After a few minutes if your thermostat is working the cooling system will get up to temperature. You then have to get more heat into it before the fan will engage again. The fan will engage for short periods as it pulls the temperature down fairly quickly.

I would not be throwing the fan center out just yet. If it engages on start up it has oil in it. It is just a matter of if you have enough. Unless you are having overheating issues I would get a few more checks done before thinking about changing it.

On really hot days when you are stationary with the A/C on you will hear the fan cycling on and off, it roars when it is engaged due to the huge volume of air it moves. You may have to open the window a bit to hear it if you car is well sound insulated. If the fan does not cycle under these conditions then you are likely to be experiencing overheating and it is time to check the rest of the cooling system and then maybe you will need to get a new thermostatic clutch fan.

Don't replace it with an electric fan, they cannot move the amount of air an engine driven fan can. As the thermostatic clutch fan idles when the system is running cool enough they don't waste power when your cruising along the highway. At cruising speed the air forced through the radiator by the vehicles motion is enough to keep the system at thermostat temperature and the clutch fan will not engage.

Hi
I have noticed I never followed up on the outcome of this problem and as I find it frustrating when, a thread never comes to a conclusion, thought I would conclude it.

The new viscous fan arrived and there was distctive difference with the new one. You can hear it roar on start up and the engine is running a lot cooler now under load.

So all is good.
Thank you for all the assistance.
Phil

Phil,lastly don't drive a Tdi with your foot to the floor when under load,you'll cook it,find a gear and speed it likes without labouring it and it'll be happy.I think too many people try and keep up with traffic when loaded and that causes most of the Tdi's supposed cooling issue's,with 3T on board cruise at 100 or so and go down a gear when she starts labouring and you will find that your speed might be low but your average road speed will stay quite reasonable over the trip.I'd do a valve set and tune before your trip also. Pat

Thanks Pat
I try to avoid foot to the floor due to the amount of smoke the car produces.
Shal avoid it even more so now.
Car is running a lot better since I changed all the lash caps, half of which were completly worn through.
Cheers

What color smoke?. Pat