2014 BMW X3 Cooling System Advice

[BISCUT]

Bought this ride in January 2025 with 74k. I'm getting on 100k now, and all is well. Actually loving this as my daily driver. I did a lot of preventative maintenance at 74k, including a radiator drain/fill with BMW coolant. I'm planning on some cooling system work a little after 100k. Water pump, thermostat, upper/lower hoses, and new coolant. Wondering if I should be replacing the expansion tank as well. Any other suggestions for cooling system work?

 

[xspeedy]

Expansion tank and turbo coolant lines

 

[SatinSilver]

@edyvw will have some good advice.

 

[edyvw]

Bought this ride in January 2025 with 74k. I'm getting on 100k now, and all is well. Actually loving this as my daily driver. I did a lot of preventative maintenance at 74k, including a radiator drain/fill with BMW coolant. I'm planning on some cooling system work a little after 100k. Water pump, thermostat, upper/lower hoses, and new coolant. Wondering if I should be replacing the expansion tank as well. Any other suggestions for cooling system work?

Coolant reservoir is a must.
Replace Mickey Mouse flange with aluminum one:
https://www.fcpeuro.com/products/bmw-aluminum-coolant-hose-flange-rein-chc0609

Use BMW OE parts for hoses and tank. Rein is good on that flange.

I would replace gaskets on oil filter housing as that one is know to mix coolant and oil between housing and exchanger.

 

[BISCUT]

@edyvw Thank you for taking the time to add the link. I will be using OEM.

 

[CleanSump]

Always replace the expansion tank when overhauling the system. The expansion tank is the #1 source of leaks as they age. I think I used a Behr last time (maybe that was the MB and the BMW got another OEM brand) I also got an anodized aluminum Mickey Mouse Flange cheap on eBay.

 

[edyvw]

Always replace the expansion tank when overhauling the system. The expansion tank is the #1 source of leaks as they age. I think I used a Behr last time (maybe that was the MB and the BMW got another OEM brand) I also got an anodized aluminum Mickey Mouse Flange cheap on eBay.

Mahle/Behr is OE on BMW and I would say MB. But I think price between OE and aftermarket is not big.