I've had a ScanGauge II for a while, but on my last trip I noticed the coolant temp creeping up at a (long light.)
I swear that in the past the coolant temp stayed nailed at 193*, but sitting in traffic it got as high as 220*.
Tried it again in the driveway and it climbed to 218* without the fan coming on.
I've checked the fuses - all are ok. Any input as to whether the likely culprit is the fan, or a thermo switch? (before I consult the Bentley)
TIA

 

K.I.S.S. rule, E.R.: check the coolant level first. (sorry if this was a 'duh' for you and you've 'been there, done that).
Other than that, if the fan does come on (albeit late) it's probably working ok. Sensors, on the other hand, can fail in stages. Try warming it up and then turn on the AC. the fan should come on no matter what the engine temp is.

 

Yep, checked the coolant level. Turned on the AC, too - no fan.
Anyone know at what temp the fan is supposed to turn on?
Dead fan in a four year old car?

 

Per the Bentley manual, the fan should come on at 221*F.

 

Mine comes on at 220*F, according to my ScanGauge.

 

Ok, so 220* isn't egregiously high. I just don't recall ever seeing it go that high before.
Is there confirmation that the fan should turn on any time the AC is on?
Thanks for the input!

 

Mine has always come on at 220*...it does seem rather high to me too.
All the MINIs i've seen have had the fan come on with the A/C...as long as the A/C was/is functioning properly.

 

Yep, standard action with almost every car I know of. Turn on AC, fan comes on no matter what the temp. On cars with dual fans, secondary fan kicks on; primary doesn't until trigger temp is reached.
And as for the fan going out on a four year old car - yep again. One of MINI's achilles heels.

 

Your thermostat is probably set at 220 and as soon as it reaches that temp, it will open and start to circulate the coolant through the rad, also triggering the fan if the car isn't moving. The coolant/water temp should immediately start to drop. My thermostat opens at 224 degrees so yours isn't out of line at 220.

 

Just a couple things to clarify here...
The thermostat can't be "set" at any certain temp. It is a mechanical device that is designed to open at whatever temp the vehicle manufacture specifies.
The thermostat on our cars open at 90.5*C or 195*F

 

Yes, I realize that but you can get them from the manufacturer "set" to open at different temps.

Maybe so, but mine opens at exactly 224 degrees F according to my Defi VSD digital display. I can "see" it open when I sit at a light as it quickly climbs to 224 then opens and drops dramatically.

Thanks for the "clarification".

 

So how hot is 'too hot' for the coolant?
For whatever reason I was thinking 230* was the 'uh-oh' point, thus my concern at seeing 220*. Sounds like it's not an uncommon occurrence.

We've only got one fan, on the driver's side, right? Hard to see a damn thing in there.

 

You are correct for other vehicle manufacturers...but MINI only lists one thermostat, with one temp.
Maybe Canada has a different listing.


Is it possible you're seeing the fan come on?

You're welcome.

 

MiniMania has a 160 F thermostat for the MINI, for one example.

http://www.minimania.com/web/Item/GTS102/InvDetail.cfm


When Detroit Tuned installed my sensors, Tuls and I sat and watched the coolant temp climb to 224 and then the thermostat opened (no fan came on) and it quickly dropped to about 190. It repeats this process every time I sit at idle for a few minutes.

 

R53- One fan, dual speed.
http://www.realoem.com/bmw/showparts...20&hg=17&fg=05

 

Yeah my fan comes on about 222 degrees. I've seen it climb up as high as 225 and 230 before coming on. Back when my SC belt broke on the freeway, I had temps as high as 250 and 260 degrees.

 

I'm sorry...I was talking about OE parts, not aftermarket.


That's very odd...i've never seen or heard of that happening with our cars. My coolant temp never goes over 220*...my fan kicks on right at that temp, and it cools right back down to 200* or so.

 

Even though the boiling point of water is 212F, and the boiling point of a 50/50 mix of coolant and water might be higher, the system is under pressure, which raises the boiling point substantially. Hence 220F is no problem at all for our cooling system.
My experience is identical to that reported by PARTSMAN.

 

Thank for all the input.
I was just worrying about the point that it becomes, suddenly and explosively, NOT under pressure.