[accel]

So one day I had a situation with engine temperature sign on in stop and go traffic. I got out of traffic as fast as I could, turning engine on and off, parked, let it cool down and since it was a couple of miles from home, decided to continue after letting engine cool down. I have engine temperature gauge in the car by the way (scangage).

On my way home I was watching the temperature all the time. I kept within typical range, but was unstable fluctuating a lot. Definitely less stable than usual. Like 99C, then 107C, then 104C and so on. And these changes were pretty fast.

Colant level was at specs.

I immediately ordered the waterpump/thermostat kit without the second thought. But then later on I decided to check error codes ising bmw logger and the cable I had. So based on DME everything was fine with the car. No errors or shadow codes of any kind.

Also, my waterpump and thermostat have ~10kmiles on it (preventative change). Which does not rule them out, but still...

And I performed waterpump bleed test - it pumps the water fine. Maybe it is too quiet, - I had to get under the car and touch it in order to get the feel of how it works mechanically.

So now I'm having doubts. What if it is not waterpump?

Anyone had experience when cooling system issues ended up being not waterpump/thermostat related? This could also be temperature sensor or radiator fan thing...

I'm almost in the position to have another ride around neighborhood reproducing symptoms. Didn't really check what was happening with radiator fan during the situarion above.

[anjuna]

what if i told you that your scan gauge could be faulty?
or that 107C is not even close to overheating?

You sound like you're an over reactive kind of person.

I had an issue on my e90 where a coolant line ruptured. No high temp code or light. Just blew up. Then I got a reservoir low light, drove it home, fixed the hose.

[Eddien123]

107 is not overheating. The system is pressurized so 100c doesn't mean your coolant is boiling. 107 can be achieved in stop and go traffic and AC on high. Or if the radiator fins are damage or blocked.

There's a menu where you can see the engine temp and I use it sometimes just to nerd out and watch the numbers and the numbers fluctuate a lot like You were saying. I've seen it jump from 89 to 102 to 94 to 104. Keep in mind coolant can change temperatures much easier than oil. Coolant temps fluctuating is not necessarily an issue. If the warning light never comes on again i wouldn't worry and for the record (to my knowledge) 107C is not hot enough to trigger a temperature warning light.

[rjahl]

Originally Posted by Eddien123

107 is not overheating. The system is pressurized so 100c doesn't mean your coolant is boiling. 107 can be achieved in stop and go traffic and AC on high. Or if the radiator fins are damage or blocked.

There's a menu where you can see the engine temp and I use it sometimes just to nerd out and watch the numbers and the numbers fluctuate a lot like You were saying. I've seen it jump from 89 to 102 to 94 to 104. Keep in mind coolant can change temperatures much easier than oil. Coolant temps fluctuating is not necessarily an issue. If the warning light never comes on again i wouldn't worry and for the record (to my knowledge) 107C is not hot enough to trigger a temperature warning light.

Our DMEs change operating temperature based on load and driving style between 95-105 degrees. There are also factors such as climate control will operate the water pump at a higher speed regardless of the coolant temp. Ditch the scangauge and monitor with a real logger such as Test0. You can then look at the true water pump RPMs, thermostat position and coolant temperature at the engine and coolant temp at the radiator. Bonus is Radiator fan speed. It's all there for the watching.

[accel]

At the moment of getting the high temperature icon on dashboard , the temperature was 122C. It's after the stop and on my further drive home the temp fluctuated up to 107.


Anyways. Since I did not want to experiment with cooling system more than that, I replaced ts and ewp (myself) even though I had doubts as you can see...

Some people suggested that ewp might work fine when the engine is cold, but mulfunction when hot.

Appears that ts&ewp was not the issue as this morning I started the engine and had some driving around neighborhood. The driving was ok and the temerature was holding ok.

Then I parked on driveway and let the engine idle with hood open. The temperature climbed up. Radiator fan was off all the time. The AC was off as well by the way.

At 110C I turned the engine off. Will look into radiator fan troubleshooting. It appears that's the only one gan that is responsible for both - AC and coolant.

[accel]

Originally Posted by rjahl

Our DMEs change operating temperature based on load and driving style between 95-105 degrees. There are also factors such as climate control will operate the water pump at a higher speed regardless of the coolant temp. Ditch the scangauge and monitor with a real logger such as Test0. You can then look at the true water pump RPMs, thermostat position and coolant temperature at the engine and coolant temp at the radiator. Bonus is Radiator fan speed. It's all there for the watching.

Test0? What's that? Software?

[rjahl]

Originally Posted by accel

Test0? What's that? Software?

Yes, it's a datalogging software written by Pheno that used BMW own ediabas protocols. Thanks to pheno's generosouty, TestO is free to use.

Failing that, you could also use INPA to simply monitor these sensors directly, just a little harder to drive and watch a computer screen.

If you need help to set this stuff up there are people on this forum that can help via teamviewer.

[accel]

Well, the fan is always OFF, even when AC is ON. Any opinions on how to diagnose other than keeping replacing parts?

[rjahl]

Originally Posted by accel

Well, the fan is always OFF, even when AC is ON. Any opinions on how to diagnose other than keeping replacing parts?

I'm pretty sure the fan will run at at a minimum RPM any time the AC compressor is turned in So I would say that zero fan rpm with a running the AC is a problem.

The fan speed is variable and in the lower speeds is very hard to hear over the engine noises.

The dme monitors fan rpm, so it should through a fault if the fan is not running as it should.

[accel]

Originally Posted by rjahl

I'm pretty sure the fan will run at at a minimum RPM any time the AC compressor is turned in So I would say that zero fan rpm with a running the AC is a problem.

The fan speed is variable and in the lower speeds is very hard to hear over the engine noises.

The dme monitors fan rpm, so it should through a fault if the fan is not running as it should.

Well, I performed all validations at driveway with hood open. So I can say the fan was not running at all with AC on 'cause I saw that. Not sure why no error codes were present. Will have to install INPA and see what jind of info that software will give me.

[rjahl]

Originally Posted by accel

Well, I performed all validations at driveway with hood open. So I can say the fan was not running at all with AC on 'cause I saw that. Not sure why no error codes were present. Will have to install INPA and see what jind of info that software will give me.

How are you reading error codes? Standard odb testers probably would show this error. Not 100 % sure because I don't use them.

[hassmaschine]

107c isn't even close to overheating - even 112c is perfectly normal. The first overheat threshold is 120c (yellow) and the next is 125c (red).

I think you are misunderstanding how the N52 cooling system functions - it can swing from 80c to 112c depending on ambient conditions and load - all perfectly normal.

[accel]

At this piont I'm suspecting the fan itself. Details in thread over here http://www.e90post.com/forums/showthread.php?t=1373873

[rjahl]

Originally Posted by accel

At this piont I'm suspecting the fan itself. Details in thread over here http://www.e90post.com/forums/showthread.php?t=1373873

Have you tried the fan run test with INPA?

[STR8-6IX]

Originally Posted by hassmaschine

107c isn't even close to overheating - even 112c is perfectly normal. The first overheat threshold is 120c (yellow) and the next is 125c (red).

I think you are misunderstanding how the N52 cooling system functions - it can swing from 80c to 112c depending on ambient conditions and load - all perfectly normal.

yea bro.. stop overreacting and drive your car. jesus

[e90dum]

Are you viewing oil temp with ur scangauge? I got a scangauge and might pull it out of the box next to my trashcan if it really can do that

I know it can monitor coolent, but ill let everyone else tell ya about that lol

[tlow98]

Originally Posted by STR8-6IX

yea bro.. stop overreacting and drive your car. jesus

Hassmachine is not saying he should drive the car, he's simply telling him how the system works.

Since the OP had an overheat message there is more than likely something amiss with his car.

It's not cool to tell him to drive it.

[tlow98]

Originally Posted by STR8-6IX

yea bro.. stop overreacting and drive your car. jesus

Hassmachine is not saying he should drive the car, he's simply telling him how the system works.

Since the OP had an overheat message there is more than likely something amiss with his car.

It's not cool to tell him to drive the car.

[hassmaschine]

Originally Posted by asahar

everyone here saying he's over reacting and to drive his car.. can't you see he got the yellow warning light, he hit 120C and pulled over. you guys are saying that this is normal? its not.

anyways, any update on this? i'm having the exact same issues, the ts and ewp are good but im experiencing overheating warnings, yellow then red. symptoms are pretty much identical to OP's.

I think you should read this thread again. it's 2 years old, I think you've had enough time.

if you're getting overheating warnings consistently, then you have an issue with the pump, fan, or thermostat. It's still perfectly normal for the temp to fluctuate between 80-115c, which is why these cars didn't come with a coolant gauge (because people would freak out).