massive sudden coolant loss with no signs

garrittg · 03-13-2023, 01:43 PM

greetings! we are having a strange issue with my wifes 2013 X1 and are hoping the knowledge/experience here might give us some ideas.

we recently had a mild coolant leak which resulted in the radiator, water pump, and thermostat getting replaced. until we are confident with the fixes i have been checking the coolant level each morning before she leaves to ensure the levels are correct. the coolant can be fine for a couple of weeks then suddenly in a short period of driving, she loses all the coolant from her engine and the car overheats. there are no signs around the cap of the coolant coming out there. there are also no signs in or around the engine of where the coolant is coming or going. we have had multiple pressure tests done on it and the shop cannot find anywhere the coolant is coming out. of course they cant reproduce it either.

this last visit to the shop, they called in to the hotline and was told that a ground wire could fail causing the water pump to not operate, overheat the system, and the coolant comes out the cap area. they did find that the ground wire was corroded and cleaned it which is good, but again there are no signs that it is coming out the cap area.

we have yet to drive it again after the ground wire fix but we are beginning to lose faith in the vehicle. i'm hoping that someone here may have experienced a similar issue or may have some advice on where to even start. any thoughts are much appreciated!

thank you

wheela · 03-13-2023, 08:14 PM

This might be a dumb question, but did they confirm your're actually out of coolant? If the pump stops you can overheat without losing coolant, that's what happened to me when my pump went out.

garrittg · 03-13-2023, 08:59 PM

greetings wheela! thank you for the reply

yes it has happened three times and each time it was out of coolant. after the first one we started keeping 8 quarts of coolant in the trunk. it usually takes 4 - 6 quarts to fill it back up when it happens so technically it isnt _all_ gone yet but over half. this last time it took 4 quarts and then emptied again in about 10 miles of country driving, taking another 4 when she got home.

i feel like i am on board with the ground wire fix, i just dont understand how there is no sign of it coming out the cap. does it leave somewhere else when it boils over?

discoboy1 · 03-25-2023, 07:08 AM

On mine it was the expansion tank, they leak at the seam

bosstones · 03-26-2023, 06:42 PM

Like Discoboy, I had a leak around the seam of my expansion tank. I can't imagine that to be the cause of so much coolant loss nut check around the underside of the seam around the expansion tank. If it is the culprit, you should also be able to see coolant/wetness of the frame beneath it (between the expansion tank and engine).

So, no trace of coolant on the underbody trays or signs of dripping/leaking along it?

tkellykbnc · 03-28-2023, 07:21 PM

I have a similar problem. Doesn’t lose a drop for days, then dumps about a gallon. Also happened after a similar repair. Bone dry on the top, but you can see it running off the skid plate. Been thinking of pulling the plate off and driving it a while so I can see the location of the leak.

Eric Heinonen · 04-02-2023, 04:18 AM

My wife has an X1 diesel 2017, had an EGR valve replaced by BMW dealer, and after that the engine was running smoothly and well, but after shutting down the engine the cooling fan was always running long time. I was wondering, that did not happen before at these temperatures, it is not hot summer yet. Yesterday we got first "engine hot" caution, amber, and after also "Engine Hot" warning with red colour. We stopped on the road, waited, and drove home just a few miles. At home, I checked coolant, couldn't see anything and filled with water...it took about 4 quarts! Now my question is; did the dealer forget to add coolant after the repair? Or was it a coincident that the fan was running always and coolant disappeared just after the EGR valve repair...? Does anybody know, if EGR valve is changed, do they need to drain the coolant system as well? Another question, we only got the warning of hot engine, but not warning about Coolant Low? Is this OK? That BMW does not warn the coolant level, just the next step which is the hot engine? I really hope the engine has not damaged... Thanks for your replies!

garrittg · 04-03-2023, 12:38 PM

thank you all for the replies. wanted to post a follow-up especially since this was so hard to find. took it to the local BMW dealer after it again dumped massive amounts of coolant and after 3 days of testing they finally replicated the issue (the shop i had previously taken it to was a highly respected specialty shop). it ended up being a bad seal on the underside of the radiator. the issue only occurred during certain heat/driving conditions and once it did the radiator just gushed fluid out of the bottom corner on the driver side. they replaced the radiator + associated hoses/connectors and the issue has not reoccurred. the elder tech in the shop said they had only seen that issue twice in 30+ years of doing BMW service. here is a vid after they found it:

https://youtube.com/shorts/86NMMBbFRl8

and i am attaching photos of the radiator after they removed it. the close-up of the corner is where the fluid was coming out of.

https://ibb.co/t8D1L0V
https://ibb.co/yR6KRJv

garrittg · 04-03-2023, 12:45 PM

Quote:

Originally Posted by bosstones

So, no trace of coolant on the underbody trays or signs of dripping/leaking along it?

based on what i could see no. the day we brought it home after the ground wire cleaning it did it again on the way home. i opened the expansion tank lid and there was no fluid i could see in it. i then heard glugging like a jug had a hole in it. i closed the expansion lid and the glugging stopped. i then got my camera ready and opened it again. the glugging started again and caught this video of fluid pouring out of the driver side of the radiator area.

https://youtube.com/shorts/8TdDsuolcWE

i showed that video to the BMW techs to hopefully help them track it down. once they were able to reproduce they confirmed it was coming from that exact area. i thought for sure once i got that video taken it would be a fast find/fix but the nature of it only leaking under certain conditions made this overly difficult.

03-13-2023, 01:43 PM	#1
garrittg Registered 0 Rep 4 Posts Drives: 2013 BMW X1 Join Date: Mar 2023 Location: Iowa iTrader: (0)	massive sudden coolant loss with no signs greetings! we are having a strange issue with my wifes 2013 X1 and are hoping the knowledge/experience here might give us some ideas. we recently had a mild coolant leak which resulted in the radiator, water pump, and thermostat getting replaced. until we are confident with the fixes i have been checking the coolant level each morning before she leaves to ensure the levels are correct. the coolant can be fine for a couple of weeks then suddenly in a short period of driving, she loses all the coolant from her engine and the car overheats. there are no signs around the cap of the coolant coming out there. there are also no signs in or around the engine of where the coolant is coming or going. we have had multiple pressure tests done on it and the shop cannot find anywhere the coolant is coming out. of course they cant reproduce it either. this last visit to the shop, they called in to the hotline and was told that a ground wire could fail causing the water pump to not operate, overheat the system, and the coolant comes out the cap area. they did find that the ground wire was corroded and cleaned it which is good, but again there are no signs that it is coming out the cap area. we have yet to drive it again after the ground wire fix but we are beginning to lose faith in the vehicle. i'm hoping that someone here may have experienced a similar issue or may have some advice on where to even start. any thoughts are much appreciated! thank you
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03-13-2023, 08:14 PM	#2
wheela Captain 279 Rep 696 Posts Drives: 2015 BMW X1 35i M-sport Join Date: Mar 2021 Location: Twin Cities MN iTrader: (0)	This might be a dumb question, but did they confirm your're actually out of coolant? If the pump stops you can overheat without losing coolant, that's what happened to me when my pump went out.
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03-13-2023, 08:59 PM	#3
garrittg Registered 0 Rep 4 Posts Drives: 2013 BMW X1 Join Date: Mar 2023 Location: Iowa iTrader: (0)	greetings wheela! thank you for the reply yes it has happened three times and each time it was out of coolant. after the first one we started keeping 8 quarts of coolant in the trunk. it usually takes 4 - 6 quarts to fill it back up when it happens so technically it isnt _all_ gone yet but over half. this last time it took 4 quarts and then emptied again in about 10 miles of country driving, taking another 4 when she got home. i feel like i am on board with the ground wire fix, i just dont understand how there is no sign of it coming out the cap. does it leave somewhere else when it boils over?
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03-25-2023, 07:08 AM	#4
discoboy1 Lieutenant Colonel 121 Rep 1,555 Posts Drives: E82 1M VO/F30 328D Join Date: Mar 2005 Location: Montreal iTrader: (3)	On mine it was the expansion tank, they leak at the seam __________________ 2011 E82 1M VO 2013 F84 35i VO
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03-26-2023, 06:42 PM	#5
bosstones Lieutenant Colonel 1154 Rep 1,543 Posts Drives: o_0 Join Date: Mar 2008 Location: Suburbia iTrader: (0)	Like Discoboy, I had a leak around the seam of my expansion tank. I can't imagine that to be the cause of so much coolant loss nut check around the underside of the seam around the expansion tank. If it is the culprit, you should also be able to see coolant/wetness of the frame beneath it (between the expansion tank and engine). So, no trace of coolant on the underbody trays or signs of dripping/leaking along it? __________________ - Jeff bosstones' flickr
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03-28-2023, 07:21 PM	#6
tkellykbnc Registered 0 Rep 2 Posts Drives: BMW X1 35i M-sport Join Date: Mar 2023 Location: North Carolina iTrader: (0)	I have a similar problem. Doesn’t lose a drop for days, then dumps about a gallon. Also happened after a similar repair. Bone dry on the top, but you can see it running off the skid plate. Been thinking of pulling the plate off and driving it a while so I can see the location of the leak.
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04-02-2023, 04:18 AM	#7
Eric Heinonen Registered 0 Rep 1 Posts Drives: BMWX1 Join Date: Apr 2023 Location: Spain iTrader: (0)	My wife has an X1 diesel 2017, had an EGR valve replaced by BMW dealer, and after that the engine was running smoothly and well, but after shutting down the engine the cooling fan was always running long time. I was wondering, that did not happen before at these temperatures, it is not hot summer yet. Yesterday we got first "engine hot" caution, amber, and after also "Engine Hot" warning with red colour. We stopped on the road, waited, and drove home just a few miles. At home, I checked coolant, couldn't see anything and filled with water...it took about 4 quarts! Now my question is; did the dealer forget to add coolant after the repair? Or was it a coincident that the fan was running always and coolant disappeared just after the EGR valve repair...? Does anybody know, if EGR valve is changed, do they need to drain the coolant system as well? Another question, we only got the warning of hot engine, but not warning about Coolant Low? Is this OK? That BMW does not warn the coolant level, just the next step which is the hot engine? I really hope the engine has not damaged... Thanks for your replies!
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04-03-2023, 12:38 PM	#8
garrittg Registered 0 Rep 4 Posts Drives: 2013 BMW X1 Join Date: Mar 2023 Location: Iowa iTrader: (0)	thank you all for the replies. wanted to post a follow-up especially since this was so hard to find. took it to the local BMW dealer after it again dumped massive amounts of coolant and after 3 days of testing they finally replicated the issue (the shop i had previously taken it to was a highly respected specialty shop). it ended up being a bad seal on the underside of the radiator. the issue only occurred during certain heat/driving conditions and once it did the radiator just gushed fluid out of the bottom corner on the driver side. they replaced the radiator + associated hoses/connectors and the issue has not reoccurred. the elder tech in the shop said they had only seen that issue twice in 30+ years of doing BMW service. here is a vid after they found it: https://youtube.com/shorts/86NMMBbFRl8 and i am attaching photos of the radiator after they removed it. the close-up of the corner is where the fluid was coming out of. https://ibb.co/t8D1L0V https://ibb.co/yR6KRJv Last edited by garrittg; 04-03-2023 at 06:17 PM..
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