[Nevrcm3]

Typical pump failure, acutely: Yellow high temp and red high temp warning with limp mode; first occurrence of it when my wife was driving it home 3 days ago.

35i xDrive M Sport model; Mileage: 56,800. We bought this used less than 1 year ago. Stuff fixed since getting it: Oil cooler gasket (recall), Charge pipe cracked (replace with Evolution; same part as F30 35i; direct fit), and the H20 pump.

I bought a pump from the local dealer (Clear Lake BMW) for speed; Parts Mgr John H gave me a great deal.

Fortunately, I found the procedure posted. It saved the day. Without this procedure I probably wouldn’t have attempted.

My son and I have done quite a bit of work on our BMWs; E46 M3 headers O.o (if you’ve done it you know how hard this is), exhaust, all fluid changes, H20 pump on his E90 330i, CAI, Eonon install, brakes/rotors, belts.

This is the first serious work on the X3…it took me a while. ~7 hrs total

I didn’t change any coolant lines or the t-stat…though now that I’m done…maybe I should of done t-stat but that’s another $115. To change all the coolant lines…I still would be at it, I think.

I agree with batlin. Is it doable? Yes. Is it a pain…absolutely. If/when it fails again would I willingly do it again vs pay an indie $400 for labor? I’ll get back to you on that…

Given the tight and small areas to work in have some extra tools: 3” socket extension, 6” socket extension, 12” socket extension, Star drive and torx, good lighting, patience.

Since the procedure is posted, I will only fill gaps in and add pointers (or how I did it) along the way to pay it forward to the next who wants to take this on. This is working a puzzle…but it’s a German puzzle so its highly logical.

Before someone asks, cross section bar = yes; electric fan out = yes; charge cooler out = yes; t-stat out = yes. All of this gives space to get the pump out.

Bleed procedure (though I shortcutted it it slightly…I will detail) is a MUST!

I started at the top of the motor and removed the cross section; easy. The fan retainer is a pain you have to push the retainer HARD INTO the radiator to release. Also detach the upper radiator line, drivers side. I did not detach the coolant line (passenger side), mid-way down, since I was pulling parts lower. The fan works out with some rotation left/raise; twist right raise futzing; keep the tranny cooler bracket out of the way too.

On to the charge cooler. Surprisingly (and me gingerly trying for the first time) the white expanding rivets were a pain. Finally, in true DIY form, I pulled hard on the ends of the plastic charge cooler support (the cover in the procedure) and voila white rivets came right out and no harm. For the charge pipe retainer locks…after getting the wings released and to stay, just make sure to get the middle out of its recess and pull down it to expose the middle of it fully (where the arrow starts in the procedure). Rest is straightforward. Install pointer; lube it with oil inside on the seals and on the outer.

For the t-stat (referencing the pic on pg 12 of the PDF), I detached in order: #4 , #3, waited until coolant stopped dripping, then #5 (since electrical). I zip tied #5 to the coolant line coming from the radiator just to keep it clear of my work space. Then I removed the 10mm bolts holding the t-stat to theH2O pump to allow some movement/positioning for #2. I released #2 from its retainer mid-way up the front of the motor for more play. Then with forward rotation of the t-stat, I got to it…what a pain! I never messed with #1 (b/c I did disconnect #2 on the pump (pg 15 of pdf), then the t-stat was out.

For the pump removal, I first removed the 3 (Al bolts) ( so now the pump is loose and can be moved around and forward. Moving the pump forward, I aimed the socket behind the electrical steering and disconnected #2 (and pulled that coolant line out with t-stat). electrical connection and #1 easy now (pg 15 jpg). Pump comes out.

Reverse order to get the pump and t-stat back in. I was careful make sure the hoses were fully seated and clamps were aligigned, positioned and tight…I did not want to go back there again if there was a leak after the bleed and pressurize procedure!!! That would simply just suck…hard. Be sure to avoid trapping/pinching the electrical connectors between stuff as re-assembly progresses. To make it easier to reconnect the coolant line quick connects, a quick lube does the trick (and will help if I have to take them off in the future)

For the bleed procedure, I did not have a battery charger. I also did not want to have the pump run the full 12 mins and run the risk of draining the battery if I had to bleed it a second time. Since the bleed procedure is done WITH THE ENGINE OFF, and if the battery drained due to a 12 min run…I am screwed, since I can’t run the engine without a primed coolant system.

What I did was simple. But do at YOUR OWN RISK. After filling coolant just by gravity, I manually primed the air out by squeezing the big radiator lines. This draws coolant from the tank into, forces air out, and fills the system. I stopped when I could feel coolant in the upper line and visually saw fluid entering the tank into the overflow line (the small diameter one from the upper radiator line to the tank).

DO NOT START THE ENGINE per the procedure, follow it to the letter. My bleed procedure though only lasted maybe 2 minutes.

I then started the engine to verify the coolant is cycling. On the climate control, max out the temp and fan speed (opens the t-stat), open the coolant tank and see fluid streaming in from the overflow line (this is very obvious). If you see that you are good. Also you should feel the heat blow thru the vents.

If you don’t obviously see coolant streaming in from the overflow line into the coolant tank or feel heat within a few minutes. Turn off the engine and bleed again.