[Theo]

This following example is the dealership not filling the M139 engine with the correct spec oil at service….. Mind Boggling.

https://www.aclassclub.co.uk/threads/wrong-oil-used-at-service-2022-a45s-m139.25313/

And somebody hired these people...

Reason why I never let the car out of my sight when it goes in, since the first car I've owned. It's two days of the year, it's worth the wait. Only with the A45s it hasn't been easier as I can take a walk or sit comfortably in the waiting room and the car will let me know when it goes in. One other thing I do is bring all the service parts and consumables myself, which I have previously bought from either the dealer or somewhere else, and I stay and watch to make sure every last part is unpacked and used/installed. That way I have complete control over the entire service. I'm committed to it. My car is my property, I'm not leaving it at the dealer expecting they'll respect and treat it as their own, because they won't, and you know why? Not because they don't want to, but because it's just another car, they can't see it as the result of my effort. The only other people that can see it as such, is your family and dearest friends, not even all your friends. Because it ultimately comes down to respecting you, deeply.

 

[Theo]

Man I didn't even notice that temporary knock. Car left the dealership in the same way it got in, if I hadn't watched every bit of the process I wouldn't have been able to tell they did anything. Can't believe I'm reading all this. Best of luck sorting it out, I would request another diff oil change like you said, but wouldn't let the car out of my sight and check the bottle before it went in.

 

[Theo]

Maybe. But there seems to be a theme running through this. It's that third service which seems to be problematic to more than one of us.

I mean, I thought the database with the oils and procedure would've been available everywhere by now. Can't screw this up. I stayed and watched the entire process it's really not less straightforward than a spark plug replacement. And if you use different oils from those listed, you're dumb. I would understand the difficulties in case where the third service was done incorrectly the first time, say back in 2023 when things were a little blurry, diff started acting up because of it and now they had to figure out the problem, is it software, is it hardware, is it oils? That's a little different. But screw this up now, in 2025?

 

[Theo]

Don't remind me, I got blood pressure through the roof that day. Then I decided the only way for them to see it, was if I got them the printed documents straight out of MB. They still looked at me like I had come from the future, but quickly realized I had come in peace.

Jokes aside, I think the guys over at the spare parts were the problem, not the garage. The garage did everything by the book, checked WIS and proceeded as instructed. They also gave me a printout of the whole thing, which did mention the right oils.

I don't mean to justify their ignorance, but it was 2023 with all that chaos worldwide, and on top of that mine was the first M139 in the country back in 3/2020 so obviously the first at the 3 year service. I'm more surprised there are dealers with the same ignorance two years later. Car is being phased out and they'll keep screwing up the diff service.

 

[Theo]

Boggles my mind one could screw up something as straightforward as this. The only thing I could understand not getting changed is the center section gear oil as there were no instructions at the time and dealers would have to take full responsibility for potential damage, even if that too was as straightforward as it could get. But that's how it works, it's protocol. I was surprised mine not only didn't hesitate to change it, they recommended it too. I was a little worried about the torque specification as there was no reference of it either and the tech would have to rely on experience, but everything went smooth and two years later it's all good. But mess up the official clutchpacks procedure, that's epic.

 

[Theo]

It takes us back on topic for this thread. I would be interested in what the garage says about your rear diff oil. I would imagine it's quite black compared to many other A45s they change the oil for. I'm sure your selection does cause much great rear torque transfer. This is probably where we need @Turbo Ed and @Theo input, but I thought our cars were 100% fwd unless otherwise needed.

Well mine and @fatty45's both came out dark, but my center section was nice and amber, you could say like new.

As for the drivetrain I thought the same and the reason I can easily powerslide as I often do in 3rd gear when exiting a turn is that I give it enough gas to cause the front wheels to lose traction, and the rear outer wheel steps in with a certain % before the car starts to understeer. Normally that will straighten you up, but if you go a little harder, that wheel can get up to 50% of power and cause you to oversteer. Then you counter steer and what that does is it shifts the power sent to the rear over to the other wheel which is now the outer wheel and you exit the turn nice and smooth. In such situations, the front wheels do very little to put the power down so the car is essentially RWD, and the reason the previous RS3 was known to understeer is that the power was sent to both the rear wheels, which kept pushing the car forward instead of trying to put it back on track (or oversteer if you went a little harder). They've allegedly fixed that with their new torque vectoring system which is similar to ours, but I've been reading that ours is still a bit more rear biased. Not sure why that would be, if it's true, but my guess is it's about the timing, i.e. ETA before the rear diff does its thing, and the algorithm which dictates the % of power that's sent to the rear based on the % of traction loss up front.

That's how it works. You drive aggressively around corners or doing launches and low rolls more often than not, you wear your tires faster because you're sending more power to the rear more often, not sure about the diff I dunno the kind of abuse it can take but I bet it'll take several sets of tires before that itself starts to go, otherwise it's a joke. In a stock car.

 

[Theo]

I got sick after that ^ post, just common cold, then we had very poor weather and didn't want to ruin the beautiful striking matte gray for a meaningless oil change, then my wife got the cold and I was looking after her, then she got covid which I got from her couple days later, spent Christmas drinking herbs and chicken soups and couldn't be at the new years either as I was still positive, albeit perfectly well otherwise, January was mad at work and then I wanted to be with my wife on her 7-day business trip to Vienna, her mother came along with us and she got covid while we were there, was caughing bad for the first couple of days but didn't take long to recover, thank God she got the shot 3 weeks earlier, sooo ended up taking the car in last Thursday.

Exactly 500ml of BMW GL-5 came out, let it bleed out to one drop coming out every 5-6 seconds, exactly 500ml of 235.63 went in. Also 5.8 liters of fresh 0W-40 AMG engine oil and filter went in to complete my unofficial 6-month service and thought it would be a good idea to check the battery while I was there, as it's now almost 4 years old, still ok according to the scan, and next official service coming up early June.

In about a month from now I need to take it in for safety and emissions inspection (the MOT equivalent), probably going to need new tires by next summer and I need to check my brake rotors thickness as I don't think they will last long either. Seriously considering picking up the Paragons for both the fronts and rears, if only for weight saving, considering I don't intend to go far with power upgrades. 11kg of unsprung weight reduction isn't bad at all and should complement my upcoming 470hp and 594nm quite nicely.

 

[Theo]

Thanks for the heads up.

Seems like the 235.63 is now widely available. That was fast, only took them four years after the first M139's hit the market.
Here's mine, luckily only took a couple of days to arrive as I ordered it last week. It's same batch as yours too.

The BMW oil has served its purpose, being the closest available alternative. Ran it for 2-2.5k miles, but it's time that the diff gets the oil that was meant for it. Booking an appointment for next week, together with an engine oil change, my usual AMG 0W-40, which I've been purchasing online since last Spring (6-month oil changes), as it's no longer available at the dealer.

 

[Theo]

LOL!!

Again, @Theo, you crack me up!!
Are you coming up to Stuttgart or I need to fill my third spot by inviting @veeeight?

If it's going to be @veeeight I will happily offer my spot, on the condition that @Akinen would film your non-ending debates throughout the whole trip. Should provide footage for the next six months.

Jokes aside, chances are I won't be able to make it. My wife works for the Greek Atomic Energy Commission and September will be a crazy month as they are hosting a European event. There will be so much going on to leave her behind, even if I could manage things at work myself. I'm sorry mate.

 

[Theo]

We're having our second heatwave of the season, first was last weekend with temps in the low 40's, which we dodged as we were away for a week so were happy with 33C, got back yesterday and today we're back in the low 40's. They say this will be the hottest summer in a very long time, with a lot of record breaking temps and long lasting heatwaves for the entire Mediterranean.

Took the A45s for a couple of errands today, which I don't normally do but wanted to refuel on my way back, from 27C in the garage, to 39C outside and if our ambient temp sensor is accurate, at some point in my route I even got 44C. Definitely a record breaking temp with this car, I don't think it has ever seen above 40C so far in three summers.

Cruising at 80-100 kph with the AC set to 23C and a nice cold breeze behind my seat, oil temp got as high as 96C, so I guess 44C ambient is truly pushing it. At Death Valley temps we'd probably be looking at over 100C. To put this into perspective, I get over 100C after three, back to back, 80-210 kph WOT runs in a typical summer night at 28C. That's what 44C does to our engines. Other than that, in the cabin it was very comfortable, the AC did a fantastic job, of course the seat fan function does help a lot, mostly when combined with the AC, helps constantly refresh your back and keeps you from sweating. And I do sweat a lot, can't stand the heat, plus I have a fairly white skin so I get sunburned quickly if not wearing a 50 SPF sunscreen.

Let's talk tires a little. Fronts got up to 56C while on the move and as high as 62C while parked for 15 minutes under the sun, then back to 56C after a few minutes of driving. These are insane temps for only a 80-100 kph cruise, I've never seen their likes before.

Took the car for another errand today, we had 37.5C so I guess it cooled down a bit lol, saw 41C at some point in my route, that's 3C down compared to the other day, oil got up to 96C and then I just went like 1/3 throttle a few times on the highway and it easily climbed to 98C. Insane...

Let's talk about last night, took it for a quick spin at 2 am, ambient at a mind boggling 34C and then 35C a bit further in my route, which I don't even remember seeing before, this heatwave is literally life threatening. And yes, I decided to see just how long I can get away with having full power, at these temps. Remember it was three back to back 80-210 kph WOT runs at 28C ambient, and during the fourth run the AC would kick in with some power loss that would progressively increase. Well at 35C I got AC kick in during the third run, so at that ambient we're talking about two full power runs, that's one run less. At this rate, if you try this at like 42C, you should be able to do just one run in full power, absolutely no more. Ridiculous.

 

[Theo]

LOL !!

What do you think would be the public reaction in the UK to even 104F, 40C???
(A normal summer's day in many parts of the world)

I am sure it would be seen as a natural catastrophe, not "quite pleasant"!!

It would sort out the UK Tuners, though !!

Trying to imagine what a UK tuner would respond to an enthusiastic owner that began his message like so:

"Good morning, I'm interested in your 500hp tune for my W177 CLA 45. I'm in Panamint Springs, California, USA and drive over to Furnace Creek several days of the week, through Death Valley National Park. Our summer temperatures are over 125F or 51C and am wondering if I would notice any significant power loss, let's say in a 60-130mph WOT run. I would like to be able to do at least five back to back runs without problems. On that note, do you also lift Vmax? I'm assuming your tune has been thoroughly tested, been hearing great things on youtube. Also assuming you provide a warranty? Thank you."

 

[Theo]

For the actual spec of the rear diff oil - best to check with the dealer as there may be more than 1 type needed.

Gear set - M-B 235.63 75W-80
Coupling - M-B 235.64 74W-70

Welcome to the forum. I'm guessing you haven't read the whole thread. There is no 235.63 available for purchase, anywhere on the planet and the only 235.64 that you can purchase is Shell's TF 0870 B, which however does say "MB 235.64" on the bottle. Gotta blame our low production volume, not even worthy of repackaging. For 235.63 you need to find an oil alternative that not only meets the weight, it has to be a hypoid GL-5 type. Luckily, no need to look for anything, as @fatty45 has already done that for us.

 

[Theo]

We're having our second heatwave of the season, first was last weekend with temps in the low 40's, which we dodged as we were away for a week so were happy with 33C, got back yesterday and today we're back in the low 40's. They say this will be the hottest summer in a very long time, with a lot of record breaking temps and long lasting heatwaves for the entire Mediterranean.

Took the A45s for a couple of errands today, which I don't normally do but wanted to refuel on my way back, from 27C in the garage, to 39C outside and if our ambient temp sensor is accurate, at some point in my route I even got 44C. Definitely a record breaking temp with this car, I don't think it has ever seen above 40C so far in three summers.

Cruising at 80-100 kph with the AC set to 23C and a nice cold breeze behind my seat, oil temp got as high as 96C, so I guess 44C ambient is truly pushing it. At Death Valley temps we'd probably be looking at over 100C. To put this into perspective, I get over 100C after three, back to back, 80-210 kph WOT runs in a typical summer night at 28C. That's what 44C does to our engines. Other than that, in the cabin it was very comfortable, the AC did a fantastic job, of course the seat fan function does help a lot, mostly when combined with the AC, helps constantly refresh your back and keeps you from sweating. And I do sweat a lot, can't stand the heat, plus I have a fairly white skin so I get sunburned quickly if not wearing a 50 SPF sunscreen.

Let's talk tires a little. Fronts got up to 56C while on the move and as high as 62C while parked for 15 minutes under the sun, then back to 56C after a few minutes of driving. These are insane temps for only a 80-100 kph cruise, I've never seen their likes before.

 

[Theo]

And once more I'd like to thank you for finding the BMW oil alternative. Your contribution was valuable for those who decide to change that out too. Big thumbs up man!

 

[Theo]

Well team, I went ahead and did a DIY Service B with rear differential service today. While I had the belly pan off for the oil filter, I noticed a small transmission fluid leak towards the back, but that adventure will be the subject of a different post. My question today deals more with the resetting of the oil condition post-clutch pack servicing.

I drained and filled both sides with the prescribed Shell TF-0870B and 1 liter was just enough to fill both sides to overflowing. I was surprised at how dark the fluid was as compared to new. I fired up Xentry and the multiplexer to perform the computer reset. I selected the right hand clutch pack computer first - adaptations - teach-in - reset oil service. It walked me through the procedure: oil above 86F? - start the car - stop the car - ignition on - ignition off - etc. until "successfully reset" came up. Super easy and intuitive. It then stated to repeat with the left clutch. So I called that computer up, ran through the same process, and right at the end, Xentry would say something like "module declined to respond to command." I repeated the reset from the beginning 3 times with the same result. No drivability issues detected during the test drive.

I seem to remember reading somewhere that one side's computer acts as the "master" for certain functions - I wonder if that's why the oil condition reset was only possible via the right hand computer. Does anyone have any experience with this or ideas?

Dealer did it exactly as you described. Mechanic went to download the relevant Xentry instructions (he also handed me a printed copy of it, which shows something interesting about the oil, I'll post in a few days) and started draining the two sides. Oil came out dark as you described, except for the center section that he did next, which looked like new, nice and amber - does it even do anything?

It's been a while since, it was before it warmed up over here so maybe that's why it went smooth without problems.

Quantities... as you said, 1 liter of Shell TF-0870 B was just enough to fill both sides to overflowing.

Center section took the whole 500ml of BMW G4, 75W80, hypoid GL-5 and a little of a second 500ml bottle I provided them for peace of mind, in case they spilled any, and I'm glad I did. Didn't purchase a spare Shell bottle but luckily I didn't need it, guess I'd better purchase two of each next time. Also worth noting, while the side clutchpacks procedure included the screw torque, there was nothing on the center section, so I trust he knew what he was doing - so far no problems anyway.

 

[Theo]

LOL!!
I shall see in September and I shall report mid-October.

Mind also asking about the new C63s? What's different in that engine compared to ours, because I'm sure they're not identical, they didn't just add an electric motor, I bet the 2 liter engine is modified too.

 

[Theo]

Everything we are seeing, from Spark Plugs to Lubricants, tells me we are dealing with a VERY low volume production vehicle, worldwide.
When I am at the engine plant in early September, I shall ask what the daily engine production numbers are.

Maybe the M139 division is down to one man, so it would be "one man all engines". Two engines a day.

 

[Theo]

All, BMW sells gear oils G1-G5 for various applications. The main differences between G4 & G5 are:

BMW G4: 75W80 weight, GL-5 for hypoid rear axles, formulated with friction modifiers for clutch-type limited slip differentials
BMW G5: 75W85 weight, GL-5 designed for "non-limited slip front differential applications from 7/2011"

Before someone brings it up, our rear is not a limited slip type that would require a friction modifier to function correctly - we have separate clutch-packs on each side that take their own special oil. Honestly, either should work just fine in this application - I selected G4 because it matches the weight requirements of MB 235.63.

Thanks for clearing that up. And since I have absolutely no interest in pioneering in any way whatsoever with this car (eyes on @Turbo Ed), I'm going to order the G4 as well.

Btw, how come you purchased two of each oil if I may ask?

 

[Theo]

@Theo
I take it they are BMW P/N's?
Please confirm or correct.

Yes. The only difference that I can see is that one is G4 and the other G5 which doesn't mean anything to us. But it has to be more than that.

 

[Theo]

I've been trying to find the difference between P/N 83222447362 and 83222471487. It seems they are G4 and G5 respectively but as @veeeight said that's just BMW's listing. They are both hypoid oils, and we know the first is a GL-5 and we know its SAE too which is spot-on. What about the second one, can somebody help?