[udunn23]

I have 2011 X3 F25 3.5i (65k) with an overheating issue. Im driving and I get the overheating warning, first yellow warning then the red warning and then limp mode.

I'm trying to narrow down the issue, I've been reading it could be the water pump or the thermostat. I don't think its the pump because you can feel the coolant being pumped through the hose.

I have noticed that radiator fan wont turn on at all, however when I turn on the AC, the fan turns on. I was stuck about 50 miles from my house, turned the AC on and was able to get home with the AC running. With the AC off I couldn't get more than 10-15 miles before it would start overheating.

What could be the cause of the fan not switching on normally? I was reading somewhere there is something called a radiator fan switch that reads the temperature of the coolant, however I'm having a hard time finding any info on it or where its located. I know on some older models its located on one of the hoses however during a quick glance I didn't notice one.

[Wgosma]

The better route to diagnosis is to scan the car for fault codes and go from there.
Electric Water pumps ( and stats) are known to fail at relatively low mileage - failing pump will show code that it's pulling excessive amperage. Near impossible to assess the coolant flow rate as you've mentioned.

You might want to open the 'hidden menu' in the instrument cluster and get continuous readout of coolant temp displayed so you can monitor, see if in fact the cooling temp is going our of range- be cautious on driving, limp mode is protecting you but get this addressed before you attempt any extended driving.

in functional system Coolant temp should to be pretty steady at 100C

hidden menu:

Good luck/Bill

[doru]

What engine do you have?

[udunn23]

its a 3.5i.

To get the codes can I just got to any auto store (pep boys, autozone, etc) or do I need to go to the dealer? There is no check engine light on currently.

[Wgosma]

I believe auto parts store scan may only yield generic codes, does depend on the type of scan tool. Dealer or independent shop will have BMW specific scanner/diagnostics.

If you are interested to DIY repairs, consider buying a code scanner- not a bad tool to have even if you end up having shop do repairs- can give one some degree of assurance shop is doing only necessary repairs and no more.

Foxwell scan tools I've read some good reviews about; I use BimmerLink cellphone app- it is BMW specific, pretty good and easy to use.
Good luck/Bill

[doru]

You need to check codes and do some testing, preferably with Rhinegold.
Usually if the WP fails, the fan start acting up, as in it start turning wildly.

Now, you said you can turn the fan on only if you hit the AC.
On a previous BMW I had - an e83 X5 v8, I had a similar situation where the car was overheating with no apparent reason. It took me some time to figure that one out. It had a similar one fan like our cars. So, if the fan is toast, it does not spin at all. I did testing with the GT1 on that one, also BMW software for that time. I could turn on and off the fan. Did numerous readings of temperatures, and then I noticed that one temperature did not jive with what I should have. The car engine was warm, and one temperature showed the expected operating (=/-100°C) temperature, but the other temperature showed close to 10°C. That engine (N62) had a dual temp sensor - one for the coolant that was going out through the WP/T-stat, and the other showed the temp of what was coming in after cooling. I can't remember which one of them showed the wrong value, but basically that dual temp sensor had one probe gone bad. Changing that solved my issue.
The way you describe your problem, could very well be something similar.
In Rheingold you could test and see what the temp sensor gives you for readings once the engine is warm and shows the overheating issue. Could be the oil/coolant sensor going bad - item #13 in this diagram, but I could be wrong. Internet diagnose is hit and miss.


GL and keep us posted

[96_Impreza]

Much info at:
https://x3.xbimmers.com/forums/showt...ermostat+pump:

My post #173:

"2011 X3 35i, original owner, 118K miles. Engine hot message. Waited for engine to cool and drove it another ten miles to mom & pop BMW shop.
Scan diagnosis: "water pump speed outside of tolerance."
Replaced water pump, new water pump bolts, thermostat kit and antifreeze.
Labor $480.00
Parts $999.97
Shop supplies/hazmat $28.80
Sales tax $118.92
Total $1627.69"

[pungo]

If it doesn't overheat with the a/c on then it is most likely the sensor that tells the fan to turn on when the coolant reaches a certain temperature. At least this is my experience I've had with many other vehicles. I'm not sure were it's located, but it's generally on the radiator or very close to it. They are usually pretty inexpensive and easy to change.

[02420X3]

Never Turn Off The Snowflake!

There's a bigger problem going on here, but leave the A/C on 24x7x365.

[udunn23]

Originally Posted by pungo

If it doesn't overheat with the a/c on then it is most likely the sensor that tells the fan to turn on when the coolant reaches a certain temperature. At least this is my experience I've had with many other vehicles. I'm not sure were it's located, but it's generally on the radiator or very close to it. They are usually pretty inexpensive and easy to change.

Yea that's what I was thinking and I know on some older models it is on a hose near the radiator, however I didn't notice one on this model (unless I didn't look close enough).

I wonder if this is the sensor (#13)? http://www.realoem.com/bmw/enUS/show...diagId=11_4451

At this point since its seems like the pump and tstat have a short life span on these vehicles and with the mileage where it is its not unlikely that they're shot or close to going. I'm just replacing them myself and we'll see if it fixes the problem. If it doesn't fix it then at least I know I can get around 50k+ out of them before they go.

I am looking into a scanner though for future problems.

I'll update after this weekend after the pump and tstat are in and if those fix the problem, fingers crossed!

[pungo]

Originally Posted by udunn23

Yea that's what I was thinking and I know on some older models it is on a hose near the radiator, however I didn't notice one on this model (unless I didn't look close enough).

I wonder if this is the sensor (#13)? http://www.realoem.com/bmw/enUS/show...diagId=11_4451

At this point since its seems like the pump and tstat have a short life span on these vehicles and with the mileage where it is its not unlikely that they're shot or close to going. I'm just replacing them myself and we'll see if it fixes the problem. If it doesn't fix it then at least I know I can get around 50k+ out of them before they go.

I am looking into a scanner though for future problems.

I'll update after this weekend after the pump and tstat are in and if those fix the problem, fingers crossed!

The pump and tstat might have a short life span, but turning the a/c on is not going to magically make them work properly. If it were me, I would not be changing those parts without first fixing the real problem with the fan not coming on unless the a/c is on. Like I said, there is most likely a sensor that tells the fan to turn on, I would be researching that before just swapping out parts that most likely are working properly therefore will not fix the problem. Is the oil temp going way up when it start to overheat?



I'm curious what you find out since I just bought a 2011 35i so this info may come in handy one day.

[udunn23]

Alright so the overheating issue appears to be fixed, we've been driving it for a little over a week with no issues.

First thing we did was replace the water pump and the thermostat. They are bolted to each other so it just makes sense to do both at once since they're both literally right there and apparently their life is very short. Its a pain and timely and can be done with basic knowledge (im not a mechanic) however it does save $400-600 in labor. To just do that swap was about 6-8 hours. Good to have an extra set of hands to help.

Once that was completed, we started the car and immediately the check engine light came on (was never on prior), we pulled the code (P0118 engine coolant temperature sensor). Which was my initial thought on what was the issue. Its #13 http://www.realoem.com/bmw/enUS/show...diagId=11_4451
We got a new one from AutoZone for $15, took 20 min to install. After driving roughly 30mi, the check engine light went off and the car was running smoothly.

The sensor could have been the problem all long, however without a diagnostic scanner, there was no way for us to tell so it was really a guessing game. At least the pump and tstat are replaced so we know we have at least 50k mi before it dies.

Thanks for all of the suggestions!

[pungo]

Great you got it figured out and shared what part failed. Like, I said previously, it was probably a sensor, not the pump or tstat, but now those should be good for awhile.

[Wgosma]

Originally Posted by udunn23

Alright so the overheating issue appears to be fixed, we've been driving it for a little over a week with no issues.

First thing we did was replace the water pump and the thermostat. They are bolted to each other so it just makes sense to do both at once since they're both literally right there and apparently their life is very short. Its a pain and timely and can be done with basic knowledge (im not a mechanic) however it does save $400-600 in labor. To just do that swap was about 6-8 hours. Good to have an extra set of hands to help.


Thanks for all of the suggestions!

Question: did you remove the WP & thermostat from below or above?

Glad your car is fixed; code reader is definitely worth having.
Thanks/Bill

[udunn23]

Originally Posted by Wgosma

Question: did you remove the WP & thermostat from below or above?

Glad your car is fixed; code reader is definitely worth having.
Thanks/Bill

We removed it from the bottom, so a ramp is necessary so you have room underneath. However a set of hands from the top help with re-installation, holding a hose, clamp, bolt, something out of the way, etc..