Overheating Issue

[racingbmwm3]

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

[tmv]

Originally Posted by upallnight

Nope.

Did you have the manual or Automatic control? Heater control should be at full max heat when you are doing the bleeding.

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.

[racingbmwm3]

Yes and Yes and this works for those cars without the heat pump also. It's to make sure air doesn't get trapped inside the heater core.

[Usmc1028]

Auto. As i've said before, i've already bleed the syste multipule times trying diff methods. Still overheating

[racingbmwm3]

let us know if the radiator swap fixes it.
and you know this was a good engine before you swapped it right?

[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?

[Doru]

I had a similar experience, but with the 4.4 (v8). Different engines, but similar result.
The culprit in my case was the double temperature switch, having one element gone bust, enough to have the t-stat closed when reaching operating temperature. The only way to "cool" down the engine was with A/C on. It was tough to find the culprit, but with INPA/GT1 it was done.
In your case, you have also a dual temp switch, located at the back of the engine - look here - item #3. If one element goes gangbusters, it will NOT read the high (operating) temperature, but a high and a cold one, assuming the engine is still warming up, and not giving the signal to open up the t-stat.
One way to check this, is take out the dual temp switch and measure it with a multimeter. I have posted this (for the 4.4) in this forum. If you search for it, you will find it, and I believe the values that should read are also posted. If I failed to post these values, then with the multimeter read the values for both sensors inside the dual switch - they should be similar. If one is bad, you will have 2 different values.

[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)

[Usmc1028]

Originally Posted by Doru

I had a similar experience, but with the 4.4 (v8). Different engines, but similar result.
The culprit in my case was the double temperature switch, having one element gone bust, enough to have the t-stat closed when reaching operating temperature. The only way to "cool" down the engine was with A/C on. It was tough to find the culprit, but with INPA/GT1 it was done.
In your case, you have also a dual temp switch, located at the back of the engine - look here - item #3. If one element goes gangbusters, it will NOT read the high (operating) temperature, but a high and a cold one, assuming the engine is still warming up, and not giving the signal to open up the t-stat.
One way to check this, is take out the dual temp switch and measure it with a multimeter. I have posted this (for the 4.4) in this forum. If you search for it, you will find it, and I believe the values that should read are also posted. If I failed to post these values, then with the multimeter read the values for both sensors inside the dual switch - they should be similar. If one is bad, you will have 2 different values.

Of course the switch would be under the intank lol! Thanks for the information ill deff check this out if switching the rad, t-stat and water valve dont work.

[Usmc1028]

As far as i know the motor was good, the motor came from a 2006 X5 involving a rear end collision. Yes its a new cap, every thing is new beside the radiator. Everything runs smooth as butter, only prob is this damn cooling prob. This weekend ill switch the Thermostat out first, if that does not cure the problem then ill switch the radiator, if that don't work then ill switch the water valve. If all the combined don't work then ill switch the dual temp switch as DORU posted. All of these will be coming from my dad's X5 Lord if none of these components cures this overheating problem. I have a big problem lol and i will have to take it to the oh so horrible dealership to see if the can tell me what the problem is, i'm not going to get them to fix it lol just diagnose. Thanks for all the help. Ill keep yall posted on how it goes. Lets just hope its something simple like a thermostat.