545i N62 Water Pump/Pulley Replacement DIY

Recently my car started making a rattling grinding noise. After removing the belt and hand spinning all items I found that the bearings in my water pump and both the tensioner and idler pulley were all failing (also found vacuum pump to be leaking). Car has 130k on it and everything appeared original. Since I have already replaced the rotors, pads, break fluid, battery, upper & lower control arms, inner & out tie rods, I decided to take on this project myself as it seemed straight forward and I have access to nearly every tool imaginable

I thought I’d share my experience, pictures, frustration. Unfortunately due to very greasy hands and time, I wasn’t able to take pictures of every step.

Removed skid plate

Removed pulley dust cap. Released tension.

Removed belt.
\

Removed radiator cover.

Disconnected hoses.

More hoses.

Removed fan.

Removed all pump hoses. 4 in total I believe.

Removed water pump pulley.

What possessed anyone to put 1 bold underneath the main engine pulley is beyond me.

Everythings out finally.

Transplanted thermostat to the new water pump with new seals.

Here’s where everything went wrong. Upon removing the water pump, this tube (next picture) is recessed and only the very end is visible. Being a new seal for this opening was included with the water pump I assumed the old seal was just stuck on. Big mistake, it was part of the tube… had to leave the car apart for nearly a week waiting for a replacement.

Since I had everything apart this far I decided to tackle the leaking oil pump.

After searching around, I found a bearing and hydraulic shop that had a new seal for the front cover of the pump. I took the pump apart and cleaned all components with gas, dried then reassembled. I also replaced to vacuum tube that attaches to the front of the pump.

Kinda scary to see it this far apart!

Old stuff.

This project ended up costing around $180 total (rebuilt water pump was cheap).
2000 miles and a good engine bay cleaning later everything is working great, with the exception of the vacuum pump which is now leaking from the large pressure fitted nipple. Guess I’ll be replacing it after all ($400+).

Hope you enjoyed reading my first thread!

Thanks for the write up.
I have a leaking Vent Hose (small pipe on top of the radiator, connecting the expansion tank) and the radiator cap is damaged.
I am even scared to ask if my pump will be damaged by the radiator cap shredding.

Originally Posted by Axion_E46

This project ended up costing around $180 total (rebuilt water pump was cheap).
2000 miles and a good engine bay cleaning later everything is working great, with the exception of the vacuum pump which is now leaking from the large pressure fitted nipple. Guess I’ll be replacing it after all ($400+).

Hope you enjoyed reading my first thread!

Did you replace your vacuum pump? How did it go? Where is it located? Thanks...

I'm going to be tackling the water pump replacement this week-end. I would like to find-out why you had to remove the bottom cover. It wasn't in your way. Was it just for cleaning?

It's not necessary. It was mostly just for cleaning. I've since done the same procedure on an E38 without jacking it up. Happy wrenching.

Originally Posted by mfumbesi

I'm going to be tackling the water pump replacement this week-end. I would like to find-out why you had to remove the bottom cover. It wasn't in your way. Was it just for cleaning?

Originally Posted by Axion_E46

It's not necessary. It was mostly just for cleaning. I've since done the same procedure on an E38 without jacking it up. Happy wrenching.

Thanks for the well wishes.
I've already tackled my water pump on Saturday (28 Jan), again thanks for this thread.

I was also swearing when I saw the hidden bolt, I only loosened (didn't completely pull it out as you, was a bit scared about re-assembling it without any way of adjusting the tension) the bottom pulley to get access and space.

So I just purchased my 2004 545i on Tuesday and after driving about 10 miles I blew the radiator hose off of the radiator. I had test driven it (pretty hard) twice and heard nothing and had no issues. The car was babied by the previous owner, only 64k miles on it.

Anyways, after all of that ordeal I got the hose on and clamped and started hearing squealing. Thought it was only coolant on the belt but after the same investigations you did, I have found the water pump is loose and squeaky. Needless to say I am glad to see this is possible to DIY. I have quite a bit of experience fixing cars but mostly older models. Nothing as advanced as this car.

I appreciate the blog, but I do have one question. I am about to order all of the parts needed, do I need to order another tube like the one you were talking about? Did you get a rebuilt pump?

Thanks again.

I am having a similar issue. Every morning, I hear a loud screeching sound coming from the engine. After about 5 minutes, the sound goes away. I already purchased the water pump. How do I know if the cause of this noise is the water pump bearing or the belt tensioner?

This is a pretty easy diagnoses. Just remove the serpentine belt and spin each wheel by hand. You will find the culprit. Look for anything binding or has any play.

Sent from my DROID2 GLOBAL using Bimmer App