cooling system overhaul
 

in the coming months I will be redoing my cooling system as preventative maint. my 04 X3 is sitting at 82k miles now. here is what Im going with

BMW coolant
OEM BMW water pump
aftermarket thermostat/housing from either ECS or Turner
aftermarket expansion tank from ECS probably
brass bleed screw
new drain screw
OEM BMW thermostat

any suggestions or thoughts on my parts list?
my hoses appear to look like new, the BMW lived in the coastal SE, then the PNW so it has lived in rubber friendly enviroments.

I cannot see paying 3x for the stewart water pump either.

I would say stock with a BMW original expansion tank. I've heard bad things about aftermarket expansion tanks such as URO and Meyle.

Do you need a new engine block crush washer? If you're also doing a coolant flush at this time its best to drain the engine block.

Need distilled water. A few gallons.

Might want to change your belts and check tensioners and pullys while the water pump is out. Definitely change the serpantine belt if you haven't already. Looks like a good list!

yup, forgot about the crush washer, I will definately drain the block when I do the water pump change..

so I will go with OEM expansion tank, I will most likely go with OEM thermostat and housing too, its only about $50 more for both items to get OEM BMW anyway.

Belt and tensioner/idler pulley were replaced last winter, but I will double check them when I have everything apart.

should I replace the water pump pulley?

I would just use the old pulley unless it's damaged. :thumbup:

You might want to reconsider the hoses. They aren't that expensive and easier to do now rather then later. I can't really comment on the X3 (only owned mined for a few weeks) but I had an e39 with M54 engine for the previous six years. I never had the rubber part of a hose burst but I have developed leaks where the rubber hose meets the plastic tube connector. It could have been due to the crimp slowly loosening over time from the engine vibrations/movement but not sure of the cause. While you have it apart and empty of coolant the hoses will be a breeze to change.

how many gallon jugs of BMW coolant do I need to pick up?

A full drain including the block is between 9 and 10 quarts or 2.5 gallons. So I would get 2 gallons of coolant to be on the safe side.

With that said when I drained my n52 I only needed a little less than 8 quarts but I didn't pull the block drain. I was able to use only 1 gallon mixed with distilled water to yield 2 gallons.

Radiator?

Same here. Even with some loss after "burping" the system I have a little mixed coolant left over.

And before anybody decides it's a good idea to stray from BMW coolant in an N52 they should read the attached PDF.