K-temp -128 in cluster?? (FIXED)

[mam4.6]

Ok, I'll give that a try. Yes, im getting good heat from the heater.

[mam4.6]

Those coolant gauges are really starting to tick me off. Unplugged both sensors, no loose wires or signs of corrosion issues. I guess I would notice if I'd have a bad water pump?

[David.X5]

Look at this repair how-to. Perhaps it is this sensor and not the one in the water pump housing. I don't know for sure which sensor determines this k-temp value.

Pelican Technical Article - BMW X5 - Radiator Outlet Temperature Sensor Replacing

[mam4.6]

Thanks, ill check into that. Found this tho... End of his post...

www.xoutpost.com/837221-post1.html

[mam4.6]

Don't think that links workin right.

"Well this really threw me for a loop! Once I was finished with everything I started to fill/bleed the system using the well documented procedure for the M62 engine. This seemed to me to be working fine and the engine sounded great and the coolant looked good. I stepped in the cabin just to rev the engine to 2000rpm to get the last remaining micro-bubbles out and as I was doing this my eye caught the temperature gauge in my cluster was pegged to right on HOT. Of course I panic thinking bye bye head gasket you fool how could you not check this before! Quickly shut the engine off and double check all my connections but the all look good. Its gotta be that thermostat I thought but its brand new and made in Germany, not the other country that we owe all our money to, how could it be bad out of the box? I decide to leave it until morning. The next day I go down pop the hood and check the coolant which has dipped a bit thats expected I top it off, and go inside to turn the key to start and see how the engine temperature rises. surprisingly as soon as I turned the key the needle pegged to the right again and the engine was COLD. This sounds like computers to me! I decided to do a reboot and yanked the negative battery terminal wait 5 mins and reconnect. This solved the temperature gauge problem! I think after disconnecting the sensor the ECU gets an error reading and it doesn't clear itself when you replace/reconnect it, the result is the pegged temperature gauge to hot. The ECU reset does the trick it clears the state of that sensor.

Well that's it I hope these tips help someone else trying to do this DIY."

[David.X5]

Glad you fixed it. I wonder why some cars need that. I replaced my sensor several years ago and didn't have to do this battery reset thing.

Perhaps we should advise people to disconnect the battery before the repair so it doesn't freak out when the temp sensor is unplugged

[bcredliner]

Did you get much air out when you bled the system?

[mam4.6]

Originally Posted by bcredliner

Did you get much air out when you bled the system?

No, I didn't get any air out. Just a solid seep of fluid with no bubbles...

[mam4.6]

Originally Posted by David.X5

Glad you fixed it. I wonder why some cars need that. I replaced my sensor several years ago and didn't have to do this battery reset thing.

Perhaps we should advise people to disconnect the battery before the repair so it doesn't freak out when the temp sensor is unplugged

Sorry for the misunderstanding there. I copied that from a separate post somewhere. I'm away on a business trip and won't be back till tomorrow evening. I'll be trying it then...

[mam4.6]

Bingo! Disconnected the battery cable for 15 minutes, and all is back to normal. Thanks for everybodies input, appreciate you all...