[GTTC]

Anyone knows the part number of the low coolant sensor plug that attaches to the expansion tank? Mine broke the holding tab and is loose in place. Been looking for a while now and cannot find anything.

[AHall]

Originally Posted by GTTC

Anyone knows the part number of the low coolant sensor plug that attaches to the expansion tank? Mine broke the holding tab and is loose in place. Been looking for a while now and cannot find anything.

Unfortunately the sensors are not sold separately from the tank. You will need to purchase an entire tank.

[pbonsalb]

Is it the sensor in the tank or the end of the wiring harness that is damaged? As noted above, buy a new tank for the sensor. For the harness end, you can spend time searching real oem for replacement harness ends and perhaps find nothing or you can find a wrecked car and salvage a pigtail to splice into your harness. Unless there is a pick and pull in your area, you may have trouble finding a salvage yard that will go search unless you pay them $100. Having a list of all years and models that use this harness end would be helpful in making the salvage search easier.

[GTTC]

Originally Posted by pbonsalb

Is it the sensor in the tank or the end of the wiring harness that is damaged? As noted above, buy a new tank for the sensor. For the harness end, you can spend time searching real oem for replacement harness ends and perhaps find nothing or you can find a wrecked car and salvage a pigtail to splice into your harness. Unless there is a pick and pull in your area, you may have trouble finding a salvage yard that will go search unless you pay them $100. Having a list of all years and models that use this harness end would be helpful in making the salvage search easier.

Yeah is the wiring harness end that plugs onto the sensor. The holding tab broke and is now just there. I spend some time yesterday looking online with no luck.

[GTTC]

Originally Posted by AHall

Unfortunately the sensors are not sold separately from the tank. You will need to purchase an entire tank.

Not the sensor itself but the connecting plug. I know is going to be a challenge.

[pbonsalb]

Zip tie to help secure any adding tension until one day you find the part.

[GTTC]

Originally Posted by pbonsalb

Zip tie to help secure any adding tension until one day you find the part.

That’s what I am thinking. I hate the thought of it. Having a beast of a ride held by ziptie 😆

[Autoregression]

Looks like mine has joined the club.

Had the car since last April, and this is the first time I’ve noticed anything.

I have an appointment in two days and will have the tank inspected/replaced.

[SolidWater]

Add me to the list of leakers.

2018 M5 with 28,000~miles. I got a low coolant warning. Saw this thread. Refilled reservoir and saw a small amount of coolant a week later. Didn’t want to risk the dangers I’ve read here so had my dealer replace the high pressure coolant reservoir and clean the injectors.

About $900. So far so good!

[AHall]

Originally Posted by SolidWater

Add me to the list of leakers.

2018 M5 with 28,000~miles. I got a low coolant warning. Saw this thread. Refilled reservoir and saw a small amount of coolant a week later. Didn’t want to risk the dangers I’ve read here so had my dealer replace the high pressure coolant reservoir and clean the injectors.

About $900. So far so good!

$900? That seems expensive. Did you consider the aftermarket machined tank for another $350.

[pbonsalb]

Originally Posted by AHall

$900? That seems expensive. Did you consider the aftermarket machined tank for another $350.

Plus another $750 for the dealer to install it….

[AHall]

Originally Posted by pbonsalb

Plus another $750 for the dealer to install it….

I think I would have to tackle that job myself. Does not seem to be $750 worth of work based on the description of the process.

[Alberta]

Originally Posted by pbonsalb

Plus another $750 for the dealer to install it….

That's a huge amount of money just for labor.

How many hours did they spend installing it ?

[pbonsalb]

It looks like the shop did more — reread the post and it includes cleaning the injectors. I am not sure what that means — remove and reinstall or just clean white coolant residue off.

[Egrunt]

Found this video of a real time removal and installation, total time 12 minutes and 2 seconds. Granted the installer works at a BMW dealership.

[Autoregression]

My total was $480 for the tank replacement and a coolant flush.

[shawntech]

2019 m850i, have brought in 3x for coolant smell and losing 1qt ht12 every 5k miles or so.

Continues to be pressure tested with no leak found, expansion tank is dry, smell is noticable at operating temperature near front left of nose especially when after run fans on.

Currently dealer agrees they can smell but cannot locate, pressure testing again but overnight this time.

Very frustrating.

[brokeboi]

Originally Posted by Tiz113

Checked under the hood a couple weeks ago and saw this white residue on the coolant reservoir and thought, huh that's not normal. Never got a light for low coolant or anything like that though.

Brought it to BMW and they found a pinhole leak. Covered under warranty thankfully.

Link to video of the tech that serviced.

https://youtube.com/shorts/FFs6PJZGmwE?feature=share

Mine is leaking at the exact same area. Did you have to replace any coils, spark plugs or injectors?

[Tiz113]

Originally Posted by brokeboi

Mine is leaking at the exact same area. Did you have to replace any coils, spark plugs or injectors?

i did not at the time, but i might do it within the next month or so for piece of mind. The car has been doing fine but its always in the back of my mind. BMW supposedly checked and said they were "fine" but i may just do replacement of all three myself because the car is out of warranty now

[fun2drv]

I had no issues in my 2019 until I was about to sell it with 51K miles. This looks to be the cap that is not holding the pressure. Going in on Wednesday for an oil change already...