[mwa12E93]

I’d replace the Oil Filter Housing Gaskets at the same time as they require loss of coolant to do the work. I am also replacing thenSerpentine belt, idlers & tensioner. (See below).

I have a 335is cabrio. There are an extra 4 braces that supposedly help quell scuttle shake (only partially successfully). They run from the rocker area immediately behind the jack point to the center of the front crossmember w/ 4 bolts each and a pair of tubular steel formed braces that run from the front center of the front crossmember to the “frame rails” to the fender support immediately forward of the strut towers.

Taking those out was a pain in the butt, but I could see no way to get at the upper mounting bolt for the pump. Also have to be removed to replace the serpentine belt & idlers. I’m doing it all (ugh).

[NoGuru]

I am pretty sure it does but does this apply to a DCT transmission?

[NoGuru]

Also should I drain all my coolant out of the system before I start this or just replace what is lost after changing the parts?

[TheMidnightNarwhal]

Originally Posted by NoGuru

Also should I drain all my coolant out of the system before I start this or just replace what is lost after changing the parts?

There is 2 drain points when draining. Radiator and one of the hoses at water pump or T stat so you are essentially already draning the coolant when removing them.

If you don't want to put fresh coolant I would just not touch the radiator drain and just refill to full.

[NoGuru]

Originally Posted by TheMidnightNarwhal

There is 2 drain points when draining. Radiator and one of the hoses at water pump or T stat so you are essentially already draning the coolant when removing them.

If you don't want to put fresh coolant I would just not touch the radiator drain and just refill to full.

I don't mind putting fresh coolant in, I just haven't seen them drain it in any of the videos I watched on the water pump replacement.

[jh_f30]

Hello E90ers! I'm usually hanging out in the F30 forums, but my family's E90 335i (2008) is throwing a thermostat code. I can definitely pull off the DIY, but a quick question that I couldn't find addressed in my brief scanning of the thread:

The car is only throwing a thermostat code, is it inadvisable to save some $ and just replace just the thermostat and leave the water pump as is? T-stats are running around $60 whereas the pumps are $300-ish. If I can save the $300 by not replacing a water pump that seems to be operating fine, I'm all for it.

[PhaseP]

Originally Posted by jh_f30

Hello E90ers! I'm usually hanging out in the F30 forums, but my family's E90 335i (2008) is throwing a thermostat code. I can definitely pull off the DIY, but a quick question that I couldn't find addressed in my brief scanning of the thread:

The car is only throwing a thermostat code, is it inadvisable to save some $ and just replace just the thermostat and leave the water pump as is? T-stats are running around $60 whereas the pumps are $300-ish. If I can save the $300 by not replacing a water pump that seems to be operating fine, I'm all for it.

For a 335 I would leave the pump alone if it is running fine. The brand new one you will replace may crack is plastic impeller housing in a few weeks and dump the coolant. From what is being posted here and from a friend's experience the N54/55 plastic impeller housing crack is either installation or manufacturing tolerance related and the saying goes if ain't broke don't fix it.

[smk99]

I went through this last night after my water pump developed the typical crack in the housing. This was the second time mine has been replaced, but the first time for me to do it myself. I suspect this made it a little easier as I didn't run into many issues with the hoses, but that top bolt was definitely a pain. It took me 2.5-3 hours.

The real reason I came on here was to let others know that the CARQUEST water pump I purchased from Advance Auto actually came with an all aluminum housing, so no more worries about cracking. This was a very pleasant surprise, as their website picture still shows it with the plastic housing. They have it listed for $396, but when you get to the page they will pop-up an ad for 25% off if you purchase it online. So not a bad deal for $300...

https://shop.advanceautoparts.com/p/...322/10626270-P

[sliebhard]

I went through this over the weekend. I was initially unsure where the leak was as it was leaking above the 4 pin connector and around to the bottom of the water pump housing.

Hoses all were in excellent condition as the pump was replaced at 70k and only has 29k on it.

I ended up filling the removed water pump with water and turning the u pipe upwards and letting it sit and low and behold, water began leaking out of the housing.

Good way to test your pump if the leak is elusive.

[marinmcgreevy]

Hi all

My car was running fine but I noticed that the cooling fan was running on high a lot. First water pump went out six years ago at 70kmi. Car now has 135kmi. Pulled the water pump and thermostat to replace. The thermostat was the original( 2007 335i sedan with manual transmission) with the metal housing.

Pulled the working water pump apart and found coolant inside the electric motor housing. See photos.

Also replacing the original serpentine belt. The belt looked good upon removal but one of the idlers ( the lowest one) had a bad bearing.

Removing and installing the water pump and thermostat is tedious and no fun as your hands get covered with coolant. The job is made much easier by removing the intake crossover tube, radiator fan and inter cooler.

[PhaseP]

The pump is designed to have coolant circulating around the rotor. Rotor is submerged in coolant during operation. The chamber the rotor is in is sealed from the rest of the housing where the windings and electronics take place. Those areas look dry in your pictures. So that doesn't indicate any problem.

[marinmcgreevy]

That is what I figured. There was some coolant in the windings but I am not sure if it was from taking things apart though. The entire chamber was not full with coolant.

[Frederik1111]

Nice guide! Thanks

[YoMuS]

Hi!

I just got the water pump for my 335i (reference code: 11515A05704, which I'm being told is the latest revision). Checked bmwofsouthatlanta.com and confirms it.

The bolts attached are the ones with reference code 11517602123 (26mm).

Is this combination correct, right?

Odd thing is the water pump got the three rubber isolators at the bolting locations, which the OP said were deprecated...

Thanks in advance!

[chaltau]

After slow coolant loss over time, it started dripping a lot last week. Car is over 103K miles and sure enough I saw a whole mess around water pump area.

I ordered the Pierburg all aluminium water pump from fcpeuro (part of kit). Hopefully it holds up better!
https://www.fcpeuro.com/products/bmw...rg-11519455978

Thank you for this addendum on XI (mine is 2011 335XI). Wheel, liner and exhaust fan has to come out. And the PS mounting bracket on driver's side is a real b*tch. Took me 1 hour to remove using a standard 10mm box wrench. Highly recommend getting a ratcheting style. I am half way there and will continue tomorrow.

Originally Posted by scorp508

I got the stuff out tonight and I'll install the new parts tomorrow. I haven't read all 11 pages of this thread, but on my 335xi there is a lot more stuff in the way and a lot less room to maneuver. The BavAuto video makes the area look like acres of lush grasslands compared to what I have.

I started following someone else's thread and then was able to fill in other steps with the BavAuto video.

I'm tired so forgive me if something here is missing. I'm doing my best to remember what I did.

1. Put the front wheels up on ramps.
2. Loosened expansion tank cap and bleeder screw.
3. Disconnected the coolant hose that goes into the AT cooler on the driver side of the intercooler, drained as much coolant as would come out. This one is one of those quick connect ends.
4. Reconnected the hose connector once it finished draining.
5. Disconnected power steering hose on passenger and driver side. These are those annoying rubber isolator things. One of the bolts snapped on mine so I guess that'll be zip tied back into place. :/
6. Removed four sway bar bolts on the front of the cross member.
7. Removed the two 10mm bolts that hold a plastic cooling line to the front of the cross member just under the sway bar. This cooling line has the sway bar held captive and you cannot rotate the sway bar down out of the way without disconnecting this from the cross member.
8. Once that cooling line is disconnected from the cross member I removed the two (one per side) small brackets the power steering hose isolators were connected through. This is a major PIA. Each bracket is one 10mm bolt that is on the top of the cross member. The passenger side one isn't too bad, but the driver side one is out of sight. A short ratcheting 10mm wrench makes it a lot easier or else you'll be turning the bolt 1/8 a turn at a time with a conventional combination wrench and doing it all by feel.
9. Once those brackets are out the sway bar can be convinced to rotate down out of the way. It will rotate behind that plastic cooling line if you push the cooling line towards the front of the car.
10. At this point I removed the radiator fan as it looked like a tight fit to try and pull the water pump out the area I had free. It isn't too bad to do.
11. I then put the right front of the car on a jack stand and removed the passenger wheel and fender liner to try and get an eye on all of the hoses. It is TIGHT in there. Be aware of the sensor on the fender liner you have to disconnect before you can pull it off the car.
12. Remove the one electrical connector from the thermostat. It has a clip on one side that you need to lift gently wile pulling the connector off.
13. I then started disconnecting hoses from the thermostat. I couldn't see how I would get the water pump out first like so many other people do. This is just a slow and steady (and annoying) step as the hoses with the traditional clamps will be stuck on rather well. I coaxed them off with some convincing from a screw driver. It took a while, they were crusty.
14. Once the hoses are disconnected you can remove the two 10mm bolts holding the thermostat to the water pump.
15. The thermostat should come out pretty easy at this point. Don't dump coolant on your face like I did.
16. With the thermostat out you should now have access to the water pump electrical connector. Gently push the tab on the passenger side of the plug in while gently nudging it off with a screwdriver.
17. With the plug off the final hose clamp should be accessible and pointing straight down. I used a short 6mm 1/4" drive socket and a very small ratchet coming in from the right wheel well.
18. Note: I did not disconnect the hose that connects the thermostat and water pump from the water pump side. I pulled that hose out while still connected to the water pump.
19. After loosening the last hose clamp I was able to use a screwdriver from the front of the car and coax off the hose.
20. Push the loose electrical plug up and out of the way so it does not get caught inside the u-shaped thermostat to water pump hose when you pull out the water pump.
21. Disconnect the ground wire from the front of the water pump. It is an E12 torx bolt.
22. Remove the bottom two E12 torx bolts from the water pump
23. Remove the top E12 torx bolt from the water pump
24. Coax the water pump out. I had to (looking up from the ground) clockwise a bit so the host attached to it would clear some stuff and come out.
25. Don't disconnect the hose from the water pump once you have it out so you can see how it is oriented and put your new thermostat to water pump hose on your new water pump.

You'll absolutely need a 3/8" swivel joint to get the lower E12 torx bolts off of the water pump as they point right at the cross member so it is impossible to get on them straight without a swivel.

I don't have one of those flexible hose clamp drivers so I used flat screwdrivers and a 6mm socket.

[chaltau]

WP is just a start. After I removed all the underbelly, wheel, liner etc. I got a good look and it is a solid mess down there. A lot of oil leak as well. Once I finish this job, I am looking at OFHG, serpentine belt, Valve Cover Gasket. The joys of owning a BMW

[chaltau]

All done and bolted up. I gave up on putting back the driver side PS bracket mounting bolt. Couldn't even get the thread started. Just zip tied it. It is not holding any weight and is wedged pretty well in the cross member. Phew! Definitely one of the hardest DIY I ever done. Now on to OFHG