[hetzle]

Hey guys,

After sitting in bumper to bumper traffic for about 30 mins I got the dreaded yellow "Engine about to overheat, please drive slowly" warning followed nearly immediately by a red "Engine overheated, pull over immediately" which I of course obeyed. After letting it cool down the warning light disappeared so I coasted it off the freeway and popped the hood but could see nothing wrong.


There was no coolant present in the engine bay nor was there white smoke or any dripping to indicate a leak. I added some distilled water to the reservoir as it was at the Min level and switched my JB4 to monitor water temps. The car would run consistently at 214* F (1 tick past the 1/4 mark on the fuel gauge) cruising on the freeway and driving around town. I did notice that my puller fan was not activated while parked at 214* F. So this leaves me with some questions:

-What are the normal running water temps for this car? This thread says 210-230* F though that seems a bit hot to me

-When should the fan activate?

-Is it possible my water pump going out? I've got 60k on the clock and am still on my first pump.

[theweebabySeamus]

Mines usually around 210-220 cruising. How much water did the system take? Has it overheated since?

[hetzle]

Originally Posted by theweebabySeamus

Mines usually around 210-220 cruising. How much water did the system take? Has it overheated since?

It took maybe 200-300ml? If you look in the reservoir the distance between Min and Max levels is maybe half an inch. And no, it hasn't overheated since but I also haven't been in stop and go traffic and the weather here has been ~50* F.

[Buttertits]

mine usually runs at or below 200 F depending on the weather

[theweebabySeamus]

Are there any codes? The water pump doesn't always kick out codes but I believe the fan will if it's failing. And yes, they can fail at 60k.

[jwzimm]

Guaranteed it is the water pump. No question.

[cahme]

I think the other thread was mine and I've had my oil temp gauge hijacked to display water temp ever since then and it is dead consistent/predictable at 230 cruising/in traffic and 210 driving spirited.

I'd bet the water pump is the issue based on
a) it's very common on these cars and
b) a fan failure should creep from yellow warning to red rather than immediate


Do you have a cable and can check the codes through the JB4? I believe some have seen some such as 2E81, 2E82, 2E83, 2E84, 2E85

[Dhillon92]

At 60k km, my waterpump was only working intermittently, some days it would be fine, others it would overheat... And then one day it just died forever.

[Buttertits]

Originally Posted by Buttertits

mine usually runs at or below 200 F depending on the weather

I thought the middle increment on the temp scale was 200, its 250. So i meant i run under 250....

usually at 240 though

[bmg4]

I bet it's your water pump as well. Try to pull codes with inpa. For some reason bmw didn't feel the need to have the car throw a cel when an integral portion of the engine fails. I would check around your oil filter housing as well. If you have signs of a leak your gasket could be causing the failed water pump. Something I noticed with my bad pump is that if you do a coolant purge by turning the car to the on position and heat all the way up(low fan) and hold the brake down for 10 seconds, instead of the pump running it will turn on the auxiliary fan. Good luck.

[jseide36]

i am having a similar problem, do you remember if your heat was on when the lights came on?

[Cory S]

Originally Posted by Buttertits

I thought the middle increment on the temp scale was 200, its 250. So i meant i run under 250....

usually at 240 though

That is oil temperature. Not water temperature.

[Cory S]

If you only started overheating while in stop and go traffic, but was fine at speeds over 20+mph, it's your radiator fan. Moving 20+mph allows air movement through the radiator, therefore, you weren't overheating. Come to a stop for a bit, and the radiator will heat soak eventually. Without any air movement through it, your water temperature increases until it reaches overheating range.......

[hetzle]

Thanks for the feedback everyone. It turned out that my water pump was producing a "weak stream" so it was replaced. Oddly they said the fan was functioning fine even though I never saw it running after pulling over at 240* F to let the car cool down. I'll update later with my running temps so we can have a good idea of what our baseline temps should be provided everything is functioning properly.

[hetzle]

So now with the fresh water pump I'm seeing temps around 220 under normal freeway driving once it's fully warmed up.

[jwzimm]

Originally Posted by hetzle

So now with the fresh water pump I'm seeing temps around 220 under normal freeway driving once it's fully warmed up.

The gauge in your cluster is oil temp, not water temp.

[hetzle]

Originally Posted by jwzimm

The gauge in your cluster is oil temp, not water temp.

I'm aware, that's why I'm using my JB4 to display water temps over my fuel gauge