B48 coolant system diagram

bimmerboy71195 · 02-05-2023, 07:51 PM

My 2021 330 is losing coolant in the main reservoir I don’t see any leaks on or under the car I purchased a coolant pressure tester kit I’m just curious if anyone has a official bmw coolant diagram to show all the compents in this system and also the smaller tanks cooling system thanks

1WickedE90 · 02-10-2023, 05:43 PM

Quote:

Originally Posted by bimmerboy71195

My 2021 330 is losing coolant in the main reservoir I don’t see any leaks on or under the car I purchased a coolant pressure tester kit I’m just curious if anyone has a official bmw coolant diagram to show all the compents in this system and also the smaller tanks cooling system thanks

https://bimmercat.com/bmw/language/en

Try this site. I would bring it to the dealer as your car still seems to be under warranty period. Good luck!

iv-128i · 02-10-2023, 07:51 PM

It seems to be a pretty common issue on b48 and b58 engines. I had it loosing coolant on my m240i and same now on my 2021 330i . My wife X2 has the same problem which became a bigger problem over time and she started loosing coolant very quickly. It ended up being a faulty/leaking coolant/water pump. Bmw replaced it under warranty. Not saying that it is your issue as well but so far for my m240i or 330i BMW is never able to find what is the problem even with pressure tests. They just say to continue top-off as needed and it is normal lol 😂

bimmerboy71195 · 02-15-2023, 05:36 PM

So I performed a pressure test today for about an hour and couldn’t find any leaks. While inspecting I noticed tons of dried up coolant all over the water pump I’m certain this is the cause of my very very slow coolant loss. I’m curious as to what part of the pump could be letting coolant seep out could be a gasket for the feed line or the return line but then I wonder if it could be leaking from the shaft that spins the pump itself.

02-05-2023, 07:51 PM	#1
bimmerboy71195 Private First Class 68 Rep 115 Posts Drives: alpine white 340xi Join Date: Feb 2018 Location: long island iTrader: (0)	B48 coolant system diagram My 2021 330 is losing coolant in the main reservoir I don’t see any leaks on or under the car I purchased a coolant pressure tester kit I’m just curious if anyone has a official bmw coolant diagram to show all the compents in this system and also the smaller tanks cooling system thanks
	Appreciate 0 Tweet Quote

02-10-2023, 07:51 PM	#3
iv-128i bmw 46 Rep 238 Posts Drives: 2017 m240i, prior : 2011 128i Join Date: Apr 2012 Location: Montreal iTrader: (1) Garage List 2011 BMW [0.00]	It seems to be a pretty common issue on b48 and b58 engines. I had it loosing coolant on my m240i and same now on my 2021 330i . My wife X2 has the same problem which became a bigger problem over time and she started loosing coolant very quickly. It ended up being a faulty/leaking coolant/water pump. Bmw replaced it under warranty. Not saying that it is your issue as well but so far for my m240i or 330i BMW is never able to find what is the problem even with pressure tests. They just say to continue top-off as needed and it is normal lol 😂 __________________ M240i F23
	Appreciate 1 bimmerboy7119568.00 Quote

02-15-2023, 05:36 PM	#4
bimmerboy71195 Private First Class 68 Rep 115 Posts Drives: alpine white 340xi Join Date: Feb 2018 Location: long island iTrader: (0)	So I performed a pressure test today for about an hour and couldn’t find any leaks. While inspecting I noticed tons of dried up coolant all over the water pump I’m certain this is the cause of my very very slow coolant loss. I’m curious as to what part of the pump could be letting coolant seep out could be a gasket for the feed line or the return line but then I wonder if it could be leaking from the shaft that spins the pump itself.
	Appreciate 0 Quote