[rallas]

I am planning some major preventative maintenance as I approach 75k miles on my 2016 435i. I don't know if I will replace the waterpump and thermostat yet (might wait till 100k for these), but I am collecting the parts needed since it will be a lot easier to do while I have the subframe dropped as part of replacing the oil pan gasket.

Which hoses associated with the waterpump and thermostat are prone to failure and should be replaced when replacing the waterpump and thermostat? I already have all the upper hoses and lines on the list as part of changing the OFHG. I was hoping to find some guidance or a complete hose kit for my car, but havn't had any luck.

[F32Fleet]

IIRC BMW only recommends every 6 yrs replacing the hoses which connect to the water pump and thermostat.

That being said I've never heard of these hoses failing.

The F-series cooling system is rather robust other than the upper connector "aka monkey ears" to the block and the hose which runs from the expansion tank across the top of the radiator into the opposite side

[rallas]

I have only found the two hoses and mikey mouse flange you mentioned in my searches. I had those on my list to replace already. I will plan on re-using the other waterpump and thermostat hoses. I come from the VW world where I have learned to replace pretty much every hose with a plastic fitting.

[terryd5150]

Originally Posted by rallas

I have only found the two hoses and mikey mouse flange you mentioned in my searches. I had those on my list to replace already. I will plan on re-using the other waterpump and thermostat hoses. I come from the VW world where I have learned to replace pretty much every hose with a plastic fitting.

Based on my experience, you're not wrong to expect to replace hoses.

I've broken the plastic fitting on at least one hose every time I've replaced the water pump and thermostat.