Changed the water pump/thermostat after 110k miles. Probably didn't need to.

[OnTheFence]

330i has 110k and both were original from 2001.
Impeller was in perfect condition. Water pump bearing seemed fine. No wobble at all.
Thermostat was working perfectly.
In highsight, and all during the repair, I was saying I should have just left it alone.
Probably did not need to do this.



Took me over 4 hours from start to finish.
This one was way harder than it was supposed to be.
1) Hoses were nearly impossible separate from the radiator.
2) Pulley was fused to the water pump. Took forever to remove
3) Water pump was PITA to remove. Removal bolt threads were mucked, and WP still stuck when they were bottomed out.
4) Water pump was hard to push back into place. Had to eventually bolt it down to get it to seat.


I contemplated just leaving the 2 old radiator hoses, but it sucks to buy parts, not use them, and reinstall old ones.
The new pats would mock me from the shelf every time I went in the garage. *****!
It was now or never. Pry bar was nearly impossible to use, since everything is plastic.
The worst case is to break the existing part, and not be able to install the new part.
I had to keep yanking for like 15 mins straight until they gave.


Oh, and I mixed blue coolant with green. LOL.


Here are some tips for the next guy:


For the lower radiator hose, once I got some movement, I used a screwdriver to pry it off a little more.



In summary,

1. Jack the car (Always 15 mins right there)
2. Removing the undertray
3. Remove airbox
4. Remove fan
5. Remove upper and lower hose (over an hour?)
6. Did not need to loosen engine lift bracket
7. Remove thermostat
8. Pulley bolts (loosen)
9. Detach belt
10. Remove pulley
11. Remove water pump
12. Replace all.
13. Bleeding,
14. Test drive (making sure the 'stat goes from 96C to 93C)
15. Next day:
16. Top off coolant. Check for leaks.
17. Jack car.
18. Reinstall the undertray

[HoZy]

Nothing wrong with preventative maintenance, Just because you had no issue now does not mean you will not have an issue in a day, week or a month.

The majority of the ownership of my E39 540i (6?) Years, it's been all preventative with only ever 1 issue that actually took my car off the road.

If the replaced parts still seem good to you, hold onto them for emergency sake as new items can also fail. Bit of a catch22

However, Any reasoning between mixing the coolants? Genuine question. It's "okay" to mix blue & green (not advised) but at least it's not like green & red(pink/orange) where it'll create a sludge monster in your system.

Cheers
Mat

[cnn]

At 110K, they (WP bearing + tstat) may seem OK, but once they go bad, they go bad very quickly, withing hundreds of miles.
You did the right thing, this way when you travel out of town, you have peace of mind!

[Dave Sal]

Always better to do it at your leisure than to get stranded somewhere. Good job.

[edjack]

What about the rad and exp tank?

[OnTheFence]

Did the expansion tank last year.
Left the radiator alone. It's original.