How hot should it get?

[BimmerTim]

I have an S50 in my SETA. It has an aftermarket temp gauge. The sender is in the stock location on the head. When idling and driving slow, the temp on the gauge will often get to 200-220F. I'm not sure what that translates to on the stock gauge. I have a slim pusher fan on the front of the radiator, and I have a brand new coolant temp switch on the radiator. The fan doesn't come on until the gauge reads pretty high.

I'm thinking that either

A. I have air in the system and the gauge reads hot because of it,
B. The temp at the head is higher than the temp at the radiator, so it's nothing to worry about.
C. It's an acceptable temp and I am an idiot.

What are your opinions on the matter?

[Fusion]

Do you have your viscous fan? 200 is ok but 220 is a bit high for casual driving. The sensor in the head is ok, thats the best place for coolant temp reading. What you might want to do is get a lower temp t-stat and the sensor in the radiator should also be lower temp.
See the "fan delete mod" thread here in the 24v forums.

[JTapper]

C.

[nando]

a lower temp t-stat isn't going to fix a broken cooling system. it can actually make the car run hotter, all it does is open it sooner.

but you do probably want the coolant temp switch that turns on earlier - the one from an E36 318is. turns on the low speed at 80c, high speed at 88c.

[BimmerTim]

I have the 80/88 switch already.

The high speed 325 fan doesn't turn on until 210F.

[Fusion]

Of course I meant the combination of 80/88 switch + 80 tstat. That seems to be the best combo, though I have yet to test it.
But yea, the high speed fan should come on earlier, cca 195 in this case.

[BimmerTim]

Oh, and I do not have the viscous fan.

[shiboujin]

My car sits at 200F and occasionally hits 210 on rough track driving. I'm bewsted too. 220 is too much imo.

[nando]

I have the 80/88 switch already.

The high speed 325 fan doesn't turn on until 210F.

your low speed resistor could be bad, that's the 80c switchpoint. It's about the 1/2 mark on my stock gauge.

[nando]

Of course I meant the combination of 80/88 switch + 80 tstat. That seems to be the best combo, though I have yet to test it.
But yea, the high speed fan should come on earlier, cca 195 in this case.

But why the 80c t-stat? what's the purpose?

you guys and your fahrenheit. what the hell is 195f? :p

[BimmerTim]

I only have a single speed fan, so only one speed is wired up. I thought I wired up the low temp, but it could have been the high temp.

My car will be coming out of storage in the next month or so, and I will try to bleed the system once again. I'll put a new t-stat and water pump in, and I'm going to get two smaller fans so I can have both temp switches wired up.

[nando]

you can wire it so both are connected. you basically just tie the two ground wires to the high speed ground (the one that goes to the relay).

basically it should come on by 80c, which might be another 10c hotter in the engine (since you are measuring in a different place). If it comes on at ~90c then your engine will be about 100c which is a bit hot. I'd bet that's what it is.

[M-technik-3]

Suggest that you spin the fan to the puller side after talking with some D stock racers. They were saying the Spal is great at pusher for effect but the radiator makes it tough to push air through it.

Meaning use the free effect of moving combined with pulling it through the core with a shroud. The shroud helps believe it or not.

[BimmerTim]

I don't need to wire both to one fan. If the low temp kicks the fan on, then the fan can't turn any more on when the high temp switch is triggered since it's a single speed fan.

I will swap the wires and see if that helps.

[flyboyx]

if your engine was indeed running at 220f, you would likely be billowing steam. do you notice any indications of the car running hot other than what your gauge tells you? what brand is your gauge? is it vdo, autometer, etc or is it one of those cheap gauges like they sell on ebay? how sure are you that your sending unit is compatible with the gauge? if you don't have the one with the correct resistance, you will get erroneous readings in your cockpit. just a couple of things to think about.