Overheating Issue

[Usmc1028]

Originally Posted by bcredliner

Have you checked if the aux fan and fan clutch is operating normally? Have you tried changing the radiator cap. Have you pressure tested the system?

Do I have it right that even with heater on when driving, after 15-20 minutes it overheats?

Does the needle peg, go to 3/4 to peg or what?

Yes the Aux fan still kicks in, Fan clutch is good as far as i know. Cap is new. No i have not pressure tested it. It only over heats to 3/4 when heater is off. When heater is on it needle is at 2/4. Temp reaches about 120c with heater off while driving and heater on it runs about 100-107 driving. Im sure it will go over 120 but i dont want it to go that far to find out.

[Usmc1028]

Originally Posted by racingbmwm3

AC system is completely separate from the heating system. And not having/using AC would make it run cooler.

Looking at RealOEM it looks like one of the hard lines is connected to the heater core but i could be looking at it wrong.

[Usmc1028]

Originally Posted by racingbmwm3

Have an infrared heat gun to do spot temperature measurements? You'll have to remove the electric fan to do this, but take spot measurements all over the radiator to see if it has hot and cold spots. should be almost uniform in temperature. If you have colder spots in the middle or scattered around it, then its the radiator.

I dont have a infrared heat gun atm, there not expensive, but im just going to swap it out to see if it cures the problem.

[Usmc1028]

Originally Posted by TerminatorX5

even though you bled the system, i bet there is still an airbubble somewhere... do the bleeding on an incline - there are procedures here and bimmer forums... if not an airbubble, then your system is not water/air tight - something is siphoning...

I wish it was a air bubble.

[Usmc1028]

Originally Posted by racingbmwm3

how many miles? sometimes a blocked or very old radiator (dirty) can cause similar symptoms, its just efficient enough at idle to radiate off the excess heat, but the extra heat of driving is just enough to push it past its peak efficiency. And thus the heater core makes up for that little bit of extra heat and keeps the system from overloading.
Can you unlock your instrument cluster to see the actual engine temperature, or use an OBD connection to do the same? I suspect that even with the heater on, its still running slightly hotter than normal, but it happens to be within the range of 'normal' so that the cluster shows it at the middle mark.

It is running hot the normal. Its running at 100-108c with heat on while driving, when its suppose to be around 92-96c, and 120c with heat off.

[Usmc1028]

Originally Posted by tmv

Just to clarify: as my understanding when bleeding to cooling system, heater control to maximum (90 degree) and fan control at minimum (1 bar), to get the latent heat pump running.

Yes, this has always worked for me in all 5 of my bmw. 1999 328i, 2001 x5 3.0, 2006 x5 3.0, 2006 530i, and well i aint don't it on the 2013 320i yet, but i'm sure its the same. All of these are stilling running fine till this day, upset the 2006 x5 3.0, but before the motor swap it ran fine when i did the cooling system.

[Usmc1028]

Originally Posted by Clockwork

I'd say a thermostat stuck closed therefore heating up adn getting rid of the heat by turning on the HVAC system does the trick (for now)

I thought when the fail, they fail in a open position. I'm i wrong?

[bcredliner]

I have to ask--where is your Dad when you are trying to swap his good parts for your potentially bad parts?

[Usmc1028]

Originally Posted by bcredliner

I have to ask--where is your Dad when you are trying to swap his good parts for your potentially bad parts?

Duck taped to a pole!

With me. Were not putting my parts in his, im just taking his to see if it works fine in mine. If i find out what it is then ill go buy that part myself. Then we got to put his all back together.

[bcredliner]

Originally Posted by Usmc1028

Duck taped to a pole!

With me. Were not putting my parts in his, im just taking his to see if it works fine in mine. If i find out what it is then ill go buy that part myself. Then we got to put his all back together.

To all--please add this to the 3,l53,472,168 ways to use duct tape. I'm off to buy another roll