Yesterday I noticed low or no heat (climate control) in my 2017 Cooper S. Figured it was a gremlin because I have been suspicious of the IHKA for a while, so let it be only to find the same problem this morning.

Using BimmerLink I found no permanent codes and 1 IHKA error code but nothing that pointed clearly at a heating system problem as such. Under info codes, however, there was this under Motor electronics:

- 20A50A: Engine cooling system: protective function for turbocharger coolant pump due to dry running active

I then cleared all error and info codes (well, most of them, again, I have a couple of gremlins but they are unrelated), and restarted the car. Upon restart, the 20A50A returned.

I was out and about so could not take corrective action other than Googling, and quickly zeroed in on low coolant as first thing to check for.

- Upon getting the car home I found 2 small puddles (maybe 4”x6”) of what was clearly coolant where the car is routinely parked.

- I put the car on ramps and waited a couple of hours for everything to cool down, then removed the skid shield/cover panel under the engine. There are clear signs in specific places of recent fluid contact, and the panel also appears to have been absorbing fluid for some time. This is new — last time I had the cover off (12/31 - just over a month ago) I did not see this pattern.

- Looking around below it looks like coolant has been collecting (I can find wet spots) and drying on the bottom of the oil pan. The front of the oil pan has streaks of what appears to be dried coolant. I can see maybe one such streak on the oil filter housing. But the actual source appears to be something higher that I cannot see from below.

- There are wet coolant spots on the underbody to the rear of the skid plate, but those are presumably whatever blew back there out of the skid panel (which was catching everything) while the car was in motion.

- I also see green — probably corrosion as well as coolant — on the starter wires (at the starter solenoid). I noticed the discoloration last year but did not find all this fluid or other symptoms, so I didn’t connect it to any sort of leak. There is coolant on the plastic wire conduits covering the starter wires, so this lines up.

- Finally, in an older thread (click here to see it), I have an unresolved issue where I have oil blowing by the oil filler cap seal (vapor that condenses on a ridge in front of the filler cap) and by the intake plenum seals for the two cylinders closest to the driver side of the car (rear of the physical engine). This is clearly the result of some kind of pressure issue, but I haven’t gotten to the bottom of it yet, and while the blow-by is minimal it is both consistent and clearly (based on dirt collected below the intake plenum) an old issue. I am unclear as to whether this unresolved internal pressure concern may be related to the coolant leak somehow, but I mention it as I seek your guidance.

I took a video showing visuals on the coolant leak tracing (click link to view), but I need help:

(1) any idea where the source could be?

(2) any references to occurrences of same?

(3) how safe or not safe do you think it is to refill the coolant and drive the car daily while I figure out diag+repair strategy? 100% not looking to blow a head gasket, harm the turbo, etc.

(4) any thoughts on possible relationship to (or non-relationship to) the still-unresolved intake/oil cap oil blow-by issue?

EDIT: I had to upload the video to another site (too big for here) but you can click here to watch it.

THANKS FOR ANY HELP

 

Hey @F56LV , this looks a lot like what you had going on in this thread you authored. Did you find a resolution? I don't have coolant in one of your photos' noted-wet locations (upper of the 2 where you pointed with a red arrow), but I see the same general collection of dried coolant on the front of your oil pan too, flowing down and then towards the rear of the pan. Identical coloring to mine (see my video here if interested).

 

Googled the code. Found this:

https://static.nhtsa.gov/odi/tsbs/20...48348-9999.pdf

In addition to whatever -- if any -- help the above is to you, for suspected coolant leaks I recommend a hot pressure test.

Top up coolant level with distilled water. Don't over fill but the less air space the better.

With the A/C off take the car out and drive it until the engine is fully up to temperature. I found in town driving gets the engine hotter quicker and hotter in less than than a freeway drive. Absent the ability to monitor actual coolant temperature -- which can be done with the right OBD2 scan tool -- I rely upon when the radiator fan(s) come on. With various cars this occurs at 212F to 217F.

Back home on your driveway raise RPMs to ~1K and hold until fan comes on. Shut off engine. As the heat load in the engine raises coolant temperature and pressure any leak will make itself known. Using a good flashlight you check possible leak areas. Be careful. In some cases hot coolant can gush out. If you have your hands or face in the way... Oh my.

You want to ID any leak and then fix it and do this until you are sure the system is leak free. A leak free system is paramount to obtaining proper cooling.

 

So nothing in that TSB that applies -- the code I have is a different one, and it says the coolant has run dry, and I have a definite coolant leak so there we go. That part is easy.

I was about to top off the coolant and do some testing, but I got under the car today -- it has been sitting cold since yesterday afternoon -- and much to my unhappiness confirmed that there is a live leak (wet as I type this, not a dry maybe-trail) running down the front (vehicle front that is) of the oil pan in at least 2 separate tracks, about 6 inches apart, until the coolant hits the front bottom edge of the oil pan. From there it runs backward across the bottom of the oil pan until it falls onto the ground (I still have the skid plate off). Some actually dripped onto the floor a bit while I was under there with the flashlight. Would have fallen in my hair if I had been a couple of inches further back under the engine.

Biggest suspect at this point is the oil filter housing (BMW part 11428585235) or gaskets between it and other parts, but I still can't see enough of the unit to be sure. Nevertheless, there are reports out there of leaks of this kind resulting from overtorquing the oil filter cover during oil changes.

I'm not a fan of this part at all -- anything that can start springing gasket leaks from an oil change is not really designed well enough to deal with human beings (every "mechanic blew up my car" story that anyone has ever had, from Jiffy Lube all the way out to dealer service, goes here). I actually use a torque wrench when I do my oil changes, and I noticed low coolant on the first oil change I did, so I don't think I broke it personally -- but if this part is at issue, at minimum I'm going to look into replacing this big chunk of plastic fun with something made of aluminum. Plastic is not a good choice for a part that can be damaged by torque operations that will take place **at least every 10K miles if you do exactly what the manufacturer says**.

Regarding a hot pressure test, even with a flashlight I can't see any of the area where this part mates to the engine block, or even the hoses that go to it. I'm going to have to pull the airbox (at minimum) to get a visual on it. The test is a good idea for sure, but the leak location is obscured to the point where engine disassembly is required to find the source, and I obviously can't run the car to do a test with the engine disassembled.

More fun ahead. I love this car, I really do, but yeesh.

 

Did you ever change the housing, on early 2014-2015 production F56 S models they have issues with the housing and most fixed under warranty. They revised the part number from the ~391 and 022 to the now ~235

We have an aftermarket solution now also. Plastic or full metal.

https://www.ecstuning.com/Search/Sit...h/11428585235/



And Metal version:

 

Appreciate you circling back on this.

I haven’t changed the part out yet — still have to pull the airbox/etc above to confirm the leak source, but pretty sure this is it for 2 reasons:

(1) I have noted coolant residue on the exterior of the oil filter housing;

(2) Since I put the front of the car up on wheel ramps approx 2 weeks ago, it has continued to leak coolant onto the garage floor. I’d say between 2-4 shop rags worth of coolant has come out completely on its own, without starting the car or waking it up (with a leak like this the car goes nowhere until repair).

I notice you have one model that has a metal body instead of the plastic. But your ship date for that item currently shows July. What are your thoughts on the longevity of the varied-manufacturer plastic models, given the nature of the beast? Do you think availability on the metal unit will open up?

When I get the “other parts out of the way” I’ll see if I can find a part number on the in-place unit.

btw, my F56S is a 2017, but its manufacture date was October 2016, and I noticed the MY2014-15 issues you mention out there as well.

 

Well, I can (barely) see the top of the oil filter housing assembly now, courtesy of pulling the intake manifold. Pics below for interested parties. Areas on the top and left (if looking at it from front of the car) of the assembly are definitely wet, and this leak has been around a while - when working on the car last fall I saw the obviously gunky area, but thought it was oil from the intake (I have oil blow-by at the bottom of intake gaskets 3 and 4).

I suppose the bottom line here could be that the gaskets on this unit need replacing, but I probably won’t be able to be sure if that is full scope of concern until I have the part off the car.

At 100K miles and given the known history of this part on the B46 engine (on both BMW and MINI-branded cars), is it smarter to just replace the part on general principle? Curious as to folks’ thoughts.



View from front of car - cylinder 1 to left





3 pics of top of oil filter housing - pretty wet up there

 

"I notice you have one model that has a metal body instead of the plastic. But your ship date for that item currently shows July. What are your thoughts on the longevity of the varied-manufacturer plastic models, given the nature of the beast? Do you think availability on the metal unit will open up?"

We can get it, just takes time. The plastic stock ones we have in stock right now and a great price, updated part number. Its the gaskets they made in the early design, they seem to leak and my guess is they were not thick enough. Seems like once replaced on the newest part you are gtg.

 

Thanks -- that detail about the gaskets is really, really helpful. Much appreciated.

Well, while researching all this I've found quite a few stories of other coolant leak sources -- the coolant reservoir, hoses running to and from same, etc., so I'm going to pull more parts off of this (and out of the way of the oil filter housing) to get a read on the full situation... and then I guess it looks like I'm going to replace that housing + gaskets. If I'm going to take it off I may as well replace the housing no matter what, at this point with 100K miles on it. More to come, I gotta disassemble more car first

Really appreciate the info.

 

Welcome, glad to help.

 

Well, I've definitely got a damaged housing. 1 gasket dead for sure, but sitting right behind the mating surface there is literally a chunk of internal surface of one of the ports missing. Replacement on deck for sure. And upon removal of the part, all coolant hanging out within the housing rolled straight down the front (well side, technically, but vehicle front) of the oil pan in 2 streams whose locations were 100% consistent with the leak pattern.

Given the plastic breakage I would recommend replacing this with the all-metal version to anyone else running into an issue here. This is the original unit from my 2017 Cooper S, vehicle production date 10/2016, so bottom line I would say the plastic -- at least of that time -- was simply not built to last.


Note split gasket in upper right corner.

That circle is the top end of the heat exchanger bypass valve assembly. I can't say for sure that all that gunk would specifically cause damage/problems, but it certainly isn't great.

Again note split gasket.

Split gasket isn't the only thing wrong here. Literally a chunk of plastic behind the gasket has flaked off and gone... well, somewhere. Hopefully it's down in this unit and not somewhere in the engine.

 

@ECSTuning - just put an order in for the replacement part (plastic) since the all-metal one is showing no availability until August. Maybe I'll switch up later this year, given my findings on my original part.

Again appreciate your help!

 

Thanks, yes. We have those ones in stock now and hope to have the metal one in the fall.

 

You bought the $110 Bremmen?
Bremmen is a good OEM, considering the MINI part for $700 is a Mahle part.

 

Yeah, I ordered the $110 Bremmen (plastic). I noticed the Mahle stamp on my existing part too.

Given that the plastic clearly failed on mine — inside one of the coolant channels no less, far away from any surface that would be clearly affected by torque during an oil change — this is a stopgap purchase for me to get the car operational. Whenever the aluminum Bremmen becomes available later this year I’ll be swapping the on-its-way plastic part out.

Totally random, I ran across a TikTok video from a mechanic with nothing but a pic of a similarly-designed oil cooler assembly used on Dodge/Chrysler vehicles, and a caption of “mechanics know” or something similar. The comments were filled with stories about this very common — but similarly prone to fail — European part design+materials choice and its consequences. There was even a comment about this being a known and common failure point on B series engines across the BMW line — which this is. The upshot would seem to be that people know to expect both gasket failure and materials failure (both shop torque-induced and not), at least in the mechanic trenches.

Maybe the Bremmen plastic will be better, but over the long haul I don’t want to take the chance. All plastic gets brittle with heat and age.

 

Got the Bremmen part yesterday and spent the day doing a bunch of work underhood -- cleaned up the "engine valley" (I guess that's what they call the part of the engine block inaccessible without removal of the intake manifold, oil filter housing, and auxiliary coolant pump) and got rid of a pretty serious amount of gunk (leaked coolant full of dirt). Also replaced the gaskets on the intake manifold, gaskets #3 and #4 had blown for sure (figured that out several months ago), and all 4 gaskets were significantly shorter than the new ones.

Going through coolant bleeding routines has been revelatory. The car lost a LOT of coolant from this problem. I'm still doing bleeding/top-off cycles (and with the 2.0L engine, there are 2 different cycles you have to go through). After I thought I was done with all that, I test drove a bit, came back, let the car sit, and found the reservoir below minimum again. Ultimately I'm going to have a coolant flush done just in case the original problem caused contamination, but still, I'm probably lucky this didn't end up a lot worse.

Oh, I cleared the 20A50A code and it has not returned. Still adding coolant to ensure that the reservoir is between min and max, but I apparently have enough in there to keep the turbo from running dry again (whew).

 

@cjv2 I think I'm having the same problem. I just took the bottom tray off and there's coolant/oil coming from the oil cooler area. Thanks for posting all of your findings. It's been really helpful. Do you have any advice? And is there good manual for this car (for torque specs and some guidance). Mine is a 2016 cooper s.

 

Sorry to hear you have the same issue, but glad my findings were helpful. I'll shoot you a private message, help you get through it. In all honesty it isn't that hard -- tedious, but not hard, at least if you are already good with tools. Since you're asking for torque specs I'm pretty sure that means you are

 

I believe I am having the same issue. My 2017 Cooper S said it was overheating yesterday so I pulled over, had it towed home, and now believe I have diagnosed the issue. When I removed the cover under the engine, I found the same scene you described in your post: coolant running down the front of the oil pan and moisture on top of the oil filter housing like you showed in your photo. I am pretty confident that the oil filter housing is the issue, I went ahead and ordered the same one you did. I am just looking for any advice or guidance that you might be willing to provide. I have tools and am somewhat capable with my car (I do my own oil changes and am familiar with other common maintenance and issues) but I am no expert and would certainly appreciate any and all advice. I am not sure what I need to remove in order to get to and remove the current oil filter housing, or what that might entail, for instance do I need to drain the oil ahead of time? Or take any other steps before just unscrewing it from the engine? Etc. I have tried to find videos on the F56 but haven't found much, I am pretty much going in blind other than the info from this forum.

Thank you in advance!

 

Sorry to hear you're having the same problem. :/ It's not hard to change but it does take time to get to the part and you will have to remove a good amount of stuff. A torque wrench is a must, and having a good base of knowledge for car maintenance. And lots of patience. The intake manifold, air filter box, radiator fan housing and auxiliary coolant pump need to be removed to get to it. I think that's all the major stuff, but there are a lot of sensors and wires to undo so just be careful and you'll be fine. I didn't drain all the oil, I just drained the oil filter. Also would recommend ordering some intake manifold gaskets. They can go bad and you'll have it off, so it's an easy fix. @cjv2 has some good resources for torque settings, etc. I'll try to find them and message you. Let me know if you have any questions!

 

Hey there @f5617 , apologies for the delay in replying -- I saw your post and will get back to you in the next 24 hours or so. Glad @robo_barista picked up on your post as well. It's pretty much what he says, and I'll reach out privately as well.

You're definitely going to have to drain the coolant (which, to be clear, is not straightforward). I would recommend draining the oil -- I mean, you (apparently, lol) don't have to but I would want as much fluid of whatever kind out of the mix and minimize the possibility of mixture in-engine (those oil and coolant channels inside the oil cooler assembly are pretty close where they mate with the engine block). So the easy thing to do is treat it as "do an oil and filter change since you're going to be in there anyway."

I'll hit you up soon.

 

That would be amazing! My part is coming in today, but I will wait for your detailed instructions/tips because I want to play this as safe as I can!

Thank you!

 

We just landed some more bremmen parts version. Metal ones are on order.

 

For anyone interested, the Bremmen unit is what I put on my F56S. 6,249 miles on it now and not one sign of trouble. Not that I expected any trouble, but FYI.

 

Thanks for the update. glad its holding up.