Here's better shots of the PDF:



And actually this next step doesn't resemble a part that I'm seeing - maybe I don't have it in the JCW, or it's massively simplified into that small part with the round cap, small coolant line, and small electrical harness in my last post?


I took a couple shots from below this morning just so you can confirm that the images in the PDF don't resemble anything from the underside either:




But you can see the blue drips do seem to come from this area, so at least I don't think I'm barking up the wrong tree with this repair.
I just need to figure out how to get the coolant to drain.

I do see what looks like another oil cooler in those lower shots, and there is what appears to be an easy to get to coolant line (yellow arrow) - maybe this is my spot to drain it, on the JCW?

 

That lower cooler looks like a transmission cooler...

I think the issue with the pdf is the multiple applications of the engine across the BMW / Mini line-up. I too saw mention of the "heat management module" and wondered where that thing is... I think you might have to break that connection at the transmission cooler. Also looks like you will have to remove that upper radiator hose that crosses in front of the oil filter housing in order to get the filter housing out. That might help drain the coolant.

It looks like that auxiliary water pump will have to come out, too.

If it makes you feel any better, I don't think you're crazy!

 

I don't remember seeing that secondary heat exchanger on my S, but I may just not have noticed it. For me, my oil filter housing took care of draining out most my coolant, so there was only a little to drain out from loosening the filter housing. From your JCW, I would go for the coolant line to the lower heat exchanger, since it is a pretty low point (i.e.- closest to the drain pan).

One tip I will throw out for installing the new oil filter housing, retorque the mounting screws a few hours after initial install. I let mine sit over night and found 1 of the 5 screws took an additional 1/4-1/2 turn to reach torque. The other 4 barely budged before clicking the torque wrench. I actually went around the fasteners with the torque wrench 3x initially, so I am sure I had them all tightened to the recommended torque. The mounting screw that took additional tightening was closest to the OEM housing failure, so I feel that may be a design related issue that may contribute to our housing failures. In any case, I suggest letting it 'relax' at least 2-4 hours and rechecking the torque on the mounting screws. I know you have the aluminum housing and I used another plastic housing, but the gasket must need some time to fully take up the clamp load of the fasteners.

 

Trusting in the AI overlords, I drafted up a pretty lengthy prompt while working today - basically amounted to "I have the factory service manual detail, but it may not be specific to the JCW, and I need to drain my coolan?" (actual prompt was MUCH more detailed) and it also suggested that lower line to what I think is the transmission oil cooler down there...
So on my lunch break, I did pop that line off and it did seem to drain quite a bit. That said, I'm not convinced that was the full system. I'm just wrapping up work, so I'll see in a bit.

I suppose worst case I will get more coolant when I pop the oil filter housing off (I was hoping not to inadvertently get coolant running into oil passages),or pop the hoses off the water pump (I don't love the idea of pouring coolant all over my AC condenser). Hopefully I drained enough that those things won't happen. I'll doublecheck my lines and see if there's maybe another one I can pull - maybe I can get to a water pump line.

Thanks, I often wonder that about myself - The PDF is very helpful, it's just these particular photos don't line up with my car exactly. Makes me wish they used a few more words in here, they would be clues as to what they are referencing, so I could google some photos of what (or even if) that part looks like on the JCW. Makes some of the steps pretty reliant on spotting a visual, like finding Waldo...

Believe it or not, the one you are talking about is actually the LOWER radiator hose - it's just stacked on top of the intercooler, so yeah - it's pretty high up there!
That's why I was worried about just popping that one - I would dump all my coolant all over my AC condenser, and make quite a mess in the process all over the garage floor... not "wife approved".

What's the auxiliary pump you speak of? Is that the little round device with the cooling line and electrical connector? I suppose that would make sense to be a pump.

That's a good point - not too different from retorquing the lug bolts after changing wheels, because of the heat - makes aluminum expand and contract. I bet plastic might be even more like that, I don't know but would make sense.

On that note, I was just thinking to myself that my torque wrench is kind of an inconvenient, large, old-school 1/2" torque wrench, click-style. It also doesn't really adjust down to the lighter torques very well. I may head to Harbor Freight to see if there's a light duty 3/8" torque wrench, I bet they have one. I am glad this TIS PDF has the torques in it!

 

I got the housing out, and sure enough...


That port has a chunk out of the plastic, AND the gasket is broken in the same spot.

Now we'll see about getting the water pump out.
It still seems pretty hidden - hoping I don't need to take the alternator off.

 

Oh man. Here's another tough spot I've landed myself in.
I ordered a bunch of parts when I found out this was broken - I paid a whole lot extra for overnight shipping too, since I need to get my car back on the road.

The water pump never showed up, and I paid a bunch extra for overnighting - made the order on Sunday, originally planning to tackle this on Tuesday/Wednesday:

Like above - it did say when I ordered it that it would ship from the vendor, and that would happen the next day - so, 2 day shipping. Fine. Land Wed,
But it's now past Friday and as per the above, it hasn't shipped yet.

And I have the car pulled apart.

I'll do some searching here, but how unreliable is the factory water pump?
The thought of having it THIS far apart and finding now that I can't replace the water pump with one that eliminates the plastic impeller is absolutely killing me, but that's a possibility.

I can look to see if there's a non-BMW part available locally. I do have a BMW dealer an hour from me, but this clearly is one of those parts where OEM isn't great.
Or I replace the thermostat and call it a day and hope my water pump is fine.
Hopefully I can get my money back including that 1 day shipping.

Thoughts?

 

That water pump order looks like ECS… Notice it says “Backordered”… I would cancel and request a refund.

Seeing your filter housing at at 60k miles make me want to go buy one to have available…

 

I agree. I think I'll cancel and request a refund.

My thoughts at this point are this... (and if you know, please confirm!)

The thermostat, I'm hoping I can get to without removing the AC compressor, and ideally the alternator either... although I see releasing the belt tension isn't too tough so that could buy me some access. That's today's mission.

I own a replacement, I have these hoses already out on this side of the motor - access may still suck, but I'm hoping I can get the bolts out and maneuver things around to JUST remove/replace the thermostat.

Then, for the water pump...
... I'm hoping I won't be bitten by not swapping it now, since it never showed up anyway.
If/when it needs to be replaced, it LOOKS like it's held onto the pulley side of that bracket, meaning I think I can remove the belt and pull it out the belt side if that repair is needed, meaning nothing I disassembled THIS time needs to be touched for that, other than draining the coolant again.

And I did buy the Schwaben Coolant Refill/Air Purge Tool, so I guess at least I'm tooled up for it when the time comes.

Has anyone replaced the water pump this way? Can you confirm?

 

I'll tell you this...
Removing the thermostat, alone-
Possible. But very difficult.
The top two bolts, no big deal at all.
Which is why I started with the bottom two. They are angled down towards at the AC compressor, and also very close to it.

I started with a 10mm on my old trusty tiny swivel breaker, which was fine for breaking it loose, but obviously it has no ratchet and there's no way, not even with a fancy tiny head 1/4” rachet, that you are getting one in there.
I ended up busting the back out of a cheap ratcheting screwdriver bit holder I had, so I could choke way up on a bit driver 10mm bit, which alone would touch the AC compressor if I fit the bit onto the bolt head with no driver attached. It's THAT tight.



I managed to finagle the bottom two bolts out-
First the breaker to crack them loose.
Then the bit driver kludge, but even that was difficult to keep on the bolts.
Fortunately once I got them mostly out, I could use two fingertips (one on each hand) to spin them out all the way.

Then the top bolts were easy with my little 1/4 driver and a short extension.

I found a couple pictures to show where the bolts are located.
The first is the thermostat on the mount unit - you can see one of the AC compressor mounts but it's obviously not in the photo.
The second is an "engine for sale" photo I found, trying to show how tight it is with the AC compressor - I traced the thermostat with red pen and marked where the bolt heads are with yellow:




Starting and tightening those two bolts is going to be fun.

 

For future thermostat fixers -
This is the fix. Shallow U-joint sockets
I have U joint adapters, but there's no room for that.

Funny thing is - I thought about buying a set over the past few months, found some nice looking inexpensive options on Amazon, but didn't pull the trigger.

So now that I'm in a pinch, Harbor Freight it is. And they only sell a set in the Icon line so... $130 it is. But at least they are nice.


Yep. Just looked - the ones I bookmarked on Amazon with 4.8 stars... $30. Buy those instead.
Maybe the smaller size bits in this set will be handy sometime somewhere across these two minis, but all I really needed was the 10mm, and all the sets have that size.

 

That shallow universal joint 10mm turned misery into no problem. Even got them torqued right.

I was able to get the new thermostat in (left arrow) and the new aluminum oil filter housing in (right arrow). I did torque the new housing a touch tighter since it's not plastic, hopefully that's a good thing.

It's all reassembly and refills now, from here to the finish line.

Interesting that I'm only on page 15 of the 42 page procedure...

 

Nice.

Definitely share your thoughts and notes regarding the TIS procedure pdf when you're all done.

 

Sorry, been traveling - had a vacation - and (nail biter) it was a 6 hour drive each way and I had to use this car. 😳

So my thoughts on the TIS procedure:
First impression - AWESOME. Super well illustrated. Factory service procedures. Can't go wrong, this rocks!

After getting into it -
My eyebrow raised at the early-on instruction to evacuate the AC and remove the AC compressor. I don't have AC tools, and... let's see if we need to really do that. (spoiler alert - you don't!).
Then there was that whole section above where the illustration matched NOTHING in my engine bay, and the description didn't say what the part was that is being removed - that I assume was the B48 motor, and we have the B48A - it's all I can figure.
Fortunately by that point, it was far enough along that I could figure things out (drained the coolant by disconnecting the coolant line from the transmission cooler that my JCW ALL4 has, but not everyone has I didn't believe).

And with the shallow U-joint sockets (really you just need a 10mm) the thermostat wasn't bad - but the two bolts on the bottom otherwise are nearly impossible, but I didn't have the procedure for that either - I'm positive though that the TIS procedure for THAT definitely would have said "remove the AC compressor" and that isn't necessary.

But that's all "judgment stuff". As much as I want to think that BMW is padding the procedures to maximize billable time for the stealerships, I can see that if those were removed it would reduce the risk of other issues or difficulties that you can't necessarily gamble on your average service bay tech to be super competent...
So maybe they are a little over-inclusive, but that helps with the illustrations.

And I made it all the way, 6 hour drive, didn't overheat!
(I had driven around 2 days before with my Bluetooth OBDC plugged in monitoring my coolant temps)

So I can't complain - SUPER glad that I had them. Thanks!

 

I did buy the vacuum coolant fill tool from ECS.
It's pretty slick.

You fire up the compressor - mine stops at about 170psi.
The part with the vacuum gauge inserts into the overflow tank, and the feed tube goes in the bucket of coolant (I filled with two bottles of coolant).
The air compressor line goes to the vacuum venturi.

Step 1 is to open the vacuum venturi and draw all the air out of the coolant system. The benefit of this is you can let it sit for a few minutes and watch the vacuum gauge. Stays constant? Holds vacuum? No leaks!

Then you throw the lever on the coolant feed, and the vacuum pulls the coolant into the system. When the vacuum stops dropping, it's full. Crazy how that works, but it does.



Then, the last step of the TIS procedure was to put the car in an automated bleed mode to get any air bubbles out.

To be fair, I buttoned up the car after filling finished. Put the covers back on - and drove the car two days, thinking I was done.

I came back to the TIS procedure a couple days later, and discovered this bleed procedure. It's simple and easy. Because I used the vacuum fill tool there was very little risk of having air in there anyways, and I drove monitoring my coolant temperature via the OBDC scanner on my phone, but I ran it anyway to be sure.
Note nothing shows up in the display - you'll have a high idle, you'll maybe hear the pump - then after quite a bit (10 minutes?) the idle drops to normal, that's how you know it's done.

 

I greatly appreciate your reporting on this procedure and following through with this thread! This will be very helpful when the time comes to run this through on my car.

 

Did you perform the step to hand crank the engine to prime the oil pump before installing the new housing? The NHTSA procedure does not have that step, but the PDF from njaremka has it. I am getting geared up to do this job, and I appreciate all the info, procedures and pictures in this post and its links.

 

No, I don't think I did but - what page was that step on?
I'm surprised, since there's no oil in the car at that point.
I'm also hoping now that there's no risk from that - if there was a risk, then I may have gotten lucky.

I just drove from Buffalo NY to the Catskills, which was about 5.5 hours of driving each way plus a lot of short-distance driving there, and made it there and back OK. About 650 miles overall.

Since I'd just changed my oil, I also hadn't had an opportunity to even do the [stupid] sensor-based oil level checks, where I would have checked the oil level with a dipstick on any other car. I prefer having confidence from confirmation, not questions and risk, when I finish a repair.

 

It was on page 15, just before installing the new Oil Filter Housing. Like I said, the NHTSB procedure does not have that step, so I am not sure how critical it actually is.

I’d have to assume if you had screwed it up, you would have known right away with low oil pressure.