When should the radiator fan turn on?

[BMWX1-35i]

At what temp does the radiator fan turn on? And is that water temp or oil temp? I ask because I have both and I was out today and stopped at a friends place but left the car running. It was about 30 min (took longer then I thought).. Come out and find the water temp at 225 and oil temp at about 160. Now I'm not sure if water temps that high (switched over from muscle cars) are normal.

I installed the water temp in the upper radiator hose which I think is the inlet to the radiator prior to cooling. I drove home which is only about 5 miles and the water temp went down to 190. When I got home I let it idle for about 10 min and saw it go back up to about 225. The radiator fan never came on and I find that strange.

[Grinchxvx]

Try turning your AC on to max and see if it comes on then, mine hasn't came on either lately but it's been really cold outside.

[BMWX1-35i]

I just tried that and no fan. Anyone know where the fan relay is?

[Grinchxvx]

Originally Posted by 135droptop

I just tried that and no fan. Anyone know where the fan relay is?

Just saw this. I think your car also Has to be really hot like 250ish or it has something to Do with what the ambient temp Sensor sees? You can test it
With max cool mode on the jb4

[BMWX1-35i]

Originally Posted by Grinchxvx

Just saw this. I think your car also Has to be really hot like 250ish or it has something to Do with what the ambient temp Sensor sees? You can test it
With max cool mode on the jb4

That sorta sounds right. I added a temp gauge and that temp sensor is in the upper radiator hose. I had the car at idle for about 25 - 35 min and the temp got up to 220 according to the after market gauge. The fan did not come on.. So I was thinking that was not a good thing.

Am I wrong or do these N54 engines run that hot? I'm use to seeing 180 - 195 temps worst case (I have always had muscle cars).

[Grinchxvx]

Originally Posted by 135droptop

That sorta sounds right. I added a temp gauge and that temp sensor is in the upper radiator hose. I had the car at idle for about 25 - 35 min and the temp got up to 220 according to the after market gauge. The fan did not come on.. So I was thinking that was not a good thing.

Am I wrong or do these N54 engines run that hot? I'm use to seeing 180 - 195 temps worst case (I have always had muscle cars).

Coolant or oil? No idea on coolant but yes I believe a lot of people run around 250 oil temp. Past 260 oil temp is looking limp mode

[BMWX1-35i]

The 220 is the coolant temp at the return hose. My oil temp has never been a problem and normally will not go above 180.

[Grinchxvx]

Originally Posted by 135droptop

The 220 is the coolant temp at the return hose. My oil temp has never been a problem and normally will not go above 180.

Not familiar with coolant temps but 180
Is low as hell for oil.

[Pig Farmer]

The OE fan relay is in the "white box" in the back of the engine bay on the passenger side where the ECU is located. Give me a minute and I'll try to find a picture and/or part number.

The fan is two speed. If stopped in traffic, I hear the fan kick into its highest speed when the water temp hits 223 degrees. I can't really hear the fan at its lowest speed even when standing in front of the car, but if you open the hood you can see/feel it running.

[Pig Farmer]

The fan relay is part number 61366901469.

In the picture, the fan relay is on the right side of the picture, tucked under some of the wires. It's the black relay with tiny white numbers on it.

[BMWX1-35i]

Originally Posted by Pig Farmer

The fan relay is part number 61366901469.

In the picture, the fan relay is on the right side of the picture, tucked under some of the wires. It's the black relay with tiny white numbers on it.

Thanks much man !!!!

[BMWX1-35i]

Originally Posted by Grinchxvx

Not familiar with coolant temps but 180
Is low as hell for oil.

Yeah, 180 - 190 is the typical oil temps I see under normal driving.

[Grinchxvx]

Originally Posted by 135droptop

Yeah, 180 - 190 is the typical oil temps I see under normal driving.

Is that halfway between the 160 and 250? My car typically runs just a little past halfway between those two. Which I calculated to like 200-210. On a hot summer day it will be 230-250 though.

[BMWX1-35i]

I have a water temp gauge installed in the upper Radiator hose. Your looking at the oil temp.

[BMWX1-35i]

Originally Posted by Grinchxvx

Is that halfway between the 160 and 250? My car typically runs just a little past halfway between those two. Which I calculated to like 200-210. On a hot summer day it will be 230-250 though.

Oh and I have the oil bypass mod done so the oil is running through the oil cooler all the time. My car does not get driven in the winter.

[Sawyerkj]

It switches on at 109 degrees Celsius on my 2010 328ix. It stays on until 106 degrees Celsius.