Author Topic: Which Radiator Fan Thermoswitch for 83 1.6 TD? (Read 4515 times)

Methanolab · « **on:** June 02, 2006, 03:58:11 pm »

I am replacing my radiator because it leaks like a sive. I got a new thermoswitch for posterity sake but I think my old one is okay. I got an 85/93 (251959481K) switch and if I am reading it correctly Bently calls for a 95/102 (321959481D95). Can anyone tell me if I am reading this correctly and which one I should use? I spend a lot of time in traffic and the mid-atlantic is usually in the 90s in the summer. Is the lower temp one okay? Thanks

Fisher · « **Reply #1 on:** June 05, 2006, 12:28:08 pm »

I'd use the higher temp one that the Bentley specifies. If you need the lower temp switch to keep the engine cool there is probably something else wrong with the cooling system.

I drive an 84 TD.

vwmike · « **Reply #2 on:** June 05, 2006, 01:51:37 pm »

Most diesels don't even get hot enough to kick the fan on and if they do it usually takes a while. I'm a fan of low temp fan switches and thermostats. Typically with a stock thermostat you'll see coolant temps in the middle of the gauge, but with a low temp thermostat you'll see temps at 1/4 to 3/8 of the gauge. A stock thermoswitch can have the fan kicking on very late. The one in my Jetta doesn't kick on until the engine is almost in the red. I've been lucky since it hasn't gotten that hot out yet this year but I'll be throwing in the low temp fan switch soon to keep the temps down this summer.

You should check what thermostat you have. I prefer the 80* one. The 70 is probably a bit too low for most climates though it worked fine when I lived in the desert. You don't want to run a really hot thermostat with a low temp fan switch or the fan will be on all the time......you might want to go down to the 80* thermostat to keep the fan from running too often.

shwartzbewithyou · « **Reply #3 on:** June 05, 2006, 01:55:11 pm »

I agree with Fisher. I've seen to many low-temp cars gum themselves up with oil deposits prematurely and die early deaths because the engine didn't run hot enough.

vwmike · « **Reply #4 on:** June 05, 2006, 01:57:03 pm »

Quote from: shwartzbewithyou

I agree with Fisher. I've seen to many low-temp cars gum themselves up with oil deposits prematurely and die early deaths because the engine didn't run hot enough.

That may also have been due to a bad thermostat which was stuck open.

Methanolab · « **Reply #5 on:** June 07, 2006, 05:47:41 am »

I am going with the lower temp one for now. It gets pretty hot here and I sit in a lot of traffic. After a week it looks like it lets the motor run at its normal temp (about 1/3 of the gauge right over the thermometer icon) without comming on but instead of the fan comming on with the gauge at 3/4 now it comes on a little over half, just passed the led. This makes me more comfortable because that seemed high to me and the fan isn't running all the time keeping it artificially cool.