No Coolant Level Sensor?? 2001 X5

[DSAviate]

Is it possible that BMW let some of our E53s out of the factor with a coolant level sensor installed but NOT wired??

It's sure starting to look that way. Why waste the money on an installed coolant sensor if you're not going to attach the signal reading circuitry?

Without a functioning coolant level sensor, one might only be able to detect a loss of coolant when the motor begins to cease.

The temp sensor may, or may not, indicate high temp when surrounded by air and not coolant.

[BMWX5CHI]

My X also has the sensor unplugged. My heater wasn't blowing hot air and I checked my antifreeze the next day. Was very low, seems like my expansion tank is leaking. If my sensor was working it would of let me know I was low. This is starting to piss me off. How the hell is that sensor not connected to anything? I hope someone out there has fixed this problem and found the right harness. If no one comes up with a solution I'm going to give BMW a call and find out wtf is going on. This is bullshit.

[X5SND]

Im also under the impression that whether or not you have a coolant sensor working or not is dependent on which Cluster/Obc your X is outfitted with. No big deal IMO...just check it yourself periodically.

Using BMW as a scapegoat for ones inability to preform a simple task that takes no longer than 10 seconds is laughable. If you are unable to check the coolant level on your vehicle, and have to rely on a dummy light....don't buy a 10 year old vehicle. These vehicles are known to be sensitive in terms of coolant system needs & failures; so why you wouldn't check it yourself is beyond me. Assume nothing when it comes to an X.

//End Rant

[BMWX5CHI]

You have a point but no need for the sarcasm. Just frustrated and kind of disappointed that BMW decided not to include a feature on my X that even a $600 94 grand am has. . . . oh well, going to replace expansion tank then do a complete overhaul of the cooling system next year as soon as the weather gets warm.

[DSAviate]

OK, I managed to get my local dealer to reluctantly cough up information on this anomaly . . . and it seems to be the best explanation so far.

X5SND - I agree that anyone with an E53 now-a-days had better be into routine maintenance and vigilant inspections. However, having a warning to advise me that one of my coolant lines just broke or fell off would be a very nice feature. Of course one would probably see white smoke coming from the engine area (daytime), but maybe not . . . it depends on where the fluid escapes. With a catastrophic loss of coolant, the low level sensor would trip several valuable seconds before you would get a red over-temp light . . . assuming you did get an over-temp light now that the temp sensor may be surrounded by air. When trying to save one's engine while moving to the side of the highway, or find some light at night, I'd prefer all the any advance notice I can get. I'm sure you check your oil level frequently as well . . . but the low oil level indicator lamp is a NICE backup that something has just run amuck.

My very helpful parts guy finally realized that I had done a fair amount of research and sought out the 30 year technician for an explanation. The salty tech immediately said, "it's an '01 X5 3.0i, right?" He claimed that there was a certain run of E53s in 2001 that were equipped with the new expansion tank that houses the low coolant sensor, WITH THE LOW COOLANT SENSOR INSTALLED, but, . . . they never wired the sensor because they hadn't yet updated to OBCs to make use of the signal.

He further relayed, that in the years following this production idiosyncrasy, many BMW techs wasted hours and hours looking for the "disconnected" harness to plug back into the sensor. The official word slowly got out that there is no harness to find. He also said that the OBC doesn't miss the signal because it isn't programmed to receive it. My experience has been that if you unplug virtually anything on the truck, especially under the hood, the OBC will not be happy. But how many of us have unconnected sensors and no advisory whatsoever.

So, I have removed my sensor so no one else wastes time looking for a non-existent harness. I will increase frequency of my periodic review of the coolant system and scan the temp meter a little more often.

[TerminatorX5]

Originally Posted by X5SND

There's a cap of some sort over the connector....whether or not it's a grounding cap I couldn't tell you at this time....if have to go investigate later today.

This is what I have on my X:

wait a second... so, this connector is NOT for the coolant level sensor? or, is it?

Was it "pre-wired"? or, it was not?

I wonder, what the pin 24 of the LCM can do - can it "report" the coolant level? does the FSW file need to be updated?

I totally understand what the old Rusty had said about the early runs of the 3.0, but didn't X5SND refitted the plug and it worked?

Please, somebody, clarify this for me... because, if the thing is not wired, we can definitely wire it up and try to make it work... Or, put this case completely to rest and move on...

[Kristophe]

Excellent post, DSAviate and appreciate your effort to dig deeper for a candid and honest explanation.

Funny that 12 years after the fact BMW is still somewhat mum about it.

I imagine BMW felt if anything went out in writing such as a service bulletin, they might be obligated to install an upgraded "High" OBC. Just my 2 cents.

[TerminatorX5]

if retrofit is possible, we would need connector 61138365340 (about $3-5), pins - 61130005199 with wire already attached, about a foot... i prefer pins without wires, so i have one continuous run without splices... then we would need a flat blade pin for the ground comb and a square female pin for the LCM... i have those part numbers somewhere - need to dig'em up...

anyone is up for a retrofit?