I've a 2012 BMW 116i F20 (turbocharged). Bought it at 2012. After two years of using it as default I got it coded with Gorilla so that it's default hp of 136 bumped up to 210. Now it's close to 29K in terms of total kilometres driven since I bought it.

I've been driving the car without any problems. No issues whatsoever since I bought it or after the coding. 4 days ago it gave a coolant level low warning that the service suggested me with topping it with some water. So I did. Then 4 days after (in the meantime, there were no more coolant errors), being the curious type, I opened the coolant tank to check it but my mistake was that I did it after a long drive. So the engine heat evaporated some more coolant when tank opened that I added some more water (I know, another mistake, it should've been more coolant this time, not water to get the 70/30 equilibrium).

Anyways, after a couple of hours, another coolant level low warning popped-up. So that I poured a litre of Shell coolant into the tank and observed the coolant temperature through the hidden access menu that night while I was driving back home.

Today, while the engine rested a whole night outside when the outside temperature was like 3-4º C, I observed the coolant temperature while I was commuting to work. Here is what it was like:

  • 45º C - when engine started
  • 86º
  • 95º
  • 105º - stable at this level after 10 minutes or so

I made a soft drive. No high revs. Also checked the coolant level by not opening the tank this time but observing it's level of liquid from the outside. It was nearly at the max. level. So no coolant got lost. I assume no leakage.

Is this kind of coolant temperature normal for my car in it's condition?

  • Am I right to assume the temperatures are in Centigrade? And it was almost freezing at night?
    – dlu
    Aug 18, 2016 at 23:47
  • @dlu yes they're centigrade Aug 19, 2016 at 4:14

3 Answers 3


From the different forum posts I've been looking at, 105℃ is about normal. It may get a bit higher under spirited driving. I don't think you have anything to worry about with the coolant temperature.

What worries me about your situation is the coolant drop. Your surge tank/reservoir should not be fluctuating that much. Either the engine is burning coolant or you have a leak somewhere. The only thing which would mitigate this in my mind is if you are not looking at the coolant levels at the same time of vehicle usage. If you are running your vehicle for an extended period of time, the level in the surge tank/reservoir is not going to be at the same level as when the vehicle has been sitting overnight and is completely cooled off. So ensure you are reading apples-to-apples when taking a look.

Coolant does not usually evaporate from the system as it is a sealed system. If your levels are below the "low" mark, there could be an issue. You will not do yourself (or your car for that matter) wrong by keeping an eye on it. If, in a few days, you notice the level has dropped again significantly, I'd have it into BMW for some maintenance. Keep a close eye on the levels as you don't want to overheat your car. If it stays relatively the same over the next couple of weeks, I doubt you have anything to worry about.

  • 1
    An often-overlooked cause for loss of coolant is a bad radiator cap. If it can't hold pressure, it will send coolant to the overflow hose and out
    – Zaid
    Dec 14, 2015 at 12:26
  • I'll keep an eye out for the coolant level for the next couple of days and report back. Thanks a lot for the great explanation. Much appreciated. Dec 14, 2015 at 14:08
  • @Zaid - Good point on the radiator cap. I had thought about this, but since no overheating was observed, I didn't think it an issue. Very valid now that you point it out. Dec 14, 2015 at 15:01
  • I forgot about this thread. Sorry. I ended up taking my car to the dealer and after the examination, they decided to change the system due to hot/cold weather changes weakening the stability of the system. Jan 30, 2016 at 12:45

It looks like the BMW part number for the thermostat is 11537600584.

A quick search on eBay seems to confirm that the thermostat setpoint is 105 °C:


As @Paulster2 said, I wouldn't be concerned about the temperature; the car isn't overheating.

The possible causes for loss of coolant are many.

Given that your car is relatively new, I'd have the cooling system pressure-tested for leaks. Don't forget the coolant cap as well. If it's acting up, you may be losing coolant through the overflow hose.

  • 2
    A great idea to search Ebay for the specific part and get the temperature data. Dec 14, 2015 at 13:10
  • @CanSürmeli yes, as long as you know the part number you can figure out information like this. The hard part is getting the part number.
    – Zaid
    Dec 14, 2015 at 13:13
  • realoem.com is great. I saw that before but forgot it. Thanks for reminding that as well. Dec 14, 2015 at 13:14

To those who are curious, i've got inside information on this. A build-in system prevents damage (read don't push to it's limits!). If the coolant temp get too high, the ECU will cut off power slowly. It's starts around a 117°C up until 125°C where we enter the emergency state. If you experience this make sure to stop quickly (not nececrely immeaditly). The same goes for oil temperature which starts at 148°C and state of emergency at 158°C.

So as long you stay under these tempertures, you should be fine.

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