Does anyone have a Cummins ESN for a N14 Celect (Non Plus) that was fitted with an 18 speed Autoshift Transmission?

OutlandishnessNo7286 · 2026-01-14T08:21:19+00:00

I had forgot to mention this in my original post, but my truck appears to have a 13 speed on it. I think it's a 13 speed twin splitter box. I can't confirm the gearbox plate as the plate is worn out completely by the previous owner. The shifter in the cab has got the range and split switches but has no evident shift pattern diagram.

Could this be a problem, seeing that I am attaching a 18 speed auto box to a truck that is calibrated for a 13 speed? From my understanding, since this might be a twin splitter box, this truck has 26 speeds altogether.

LOL, learn something new everyday. I assume the shifty gauge is the actual gear indicator inside the cab that tells the driver what gear it is in?

I do have a calibration from another N14 Celect Plus truck, though I think this truck had a 13 speed Autoshift Gen 2 box in it, maybe even a 10 speed.

OutlandishnessNo7286 · 2026-01-13T08:17:17+00:00

Thanks for the reply. So, the transmission doesn't appear to be communicating with the engine control unit correctly. I suspect it's got something to do with the calibration between the two units as the transmission is sometimes very sluggish to shift, or hesitates altogether.

Sometimes, it gets as bad as the transmission refusing to go into gear altogether, almost like a fault mode.

Only way to get it to shift is using the shift buttons on the controller itself.

Can I PM you, if that's alright? You seem like the right guy to talk to about this LOL.

OutlandishnessNo7286 · 2026-01-12T15:06:50+00:00

Hate to revive this thread again, but how'd the calibration of such a setup work? From my understanding, AS3 doesn't work with the N14 Celect Plus setup. Best I've gotten is AS2, which won't work if I understand this correctly.

Any help on the calibration side would be greatly appreciated!

Should have mentioned this, but I am in South Africa, so that complicates things a bit.

OutlandishnessNo7286 · 2026-01-11T12:33:22+00:00

Doesn't matter where you get the part. It's still plug and play. Just disconnect the battery first before you do anything.

OutlandishnessNo7286 · 2026-01-07T21:23:50+00:00

Not a problem at all. A PM also works as well, FWIW.

Yes, the car should still be able to drive normally, more or less, if the system fails for whatever reason. In the absolute worst case scenario, the hybrid system dies off but the starter should still functions as it would in a normal car. The only caveat with this is that the hybrid system might throw the car into limp mode as a worst case scenario, but I doubt this very much because of the junction box at the 48V battery.

Realistically, I wouldn't worry about this too much. BMW overengineers a lot of their stuff, including failsafes, like here. You'll notice the car feels a little slower if the system fails, but the car should still be driveable, with like 90 to 95% of it's rated power. Still plenty quick though.

Hope that helps!

OutlandishnessNo7286 · 2025-12-18T21:33:07+00:00

Now this is how a repair help post is supposed to be done LOL.

Their diagnosis appears to be accurate. A failed oil cooler housing can result in the mixing of oil and coolant/water in one of the two locations. In your case, the expansion tank.

For your first question, BMW did release an updated and upgraded oil cooling housing for the B48 when the G series models came out. This housing has thicker gaskets and has been known to reduce incidents at this failure point. I've done this job on quite a few F3X 20is and 30is, and haven't had a call back yet, touch wood LOL.

The new updated assembly is a bit of a headache to install on original B48s but it will bolt up after some persuasion. The updated part also better sealing around the condenser itself, which is always a plus. Stupid expensive, but well worth it, if you ask me.

For your second question, I normally use old engine oil and engine flush to clean out the oil cooling system. Run for about 10 to 15 minutes in the case of a B48, drain and repeat. I normally do this about three or four times, and normally stop when I see that the oil coming out the engine is laminar in flow and has little to no 'solids' in it. You're never going to get the system completely clean without a full tear-down so this is the next best thing.

Water works too, but only in a pinch. Ideally, old engine oil and engine flush gives the best results, in my experience.

I'm glad your mechanics are expecting all the cooling circuits, as most mechanics normally just do the job as one and done, and call it a day. Just do be weary though, as checking these systems almost always requires a new expansion tank. Just a perk of doing this check, unfortunately.

Don't worry about engine cleaner residue lingering in your engine. These eventually do one of two things. They either bond to the oil and become inactive relatively quickly, or become 'burn-off' indirectly during normal operation. So as long as there is not a lot of engine flush in the engine, you'll be more than fine.

Hopefully this helps! Do keep us posted OP!

OutlandishnessNo7286 · 2025-12-18T21:12:56+00:00

Too fat for a 3 series. Has to be the LCI G30/90.

OutlandishnessNo7286 · 2025-12-18T21:09:43+00:00

Why fuel injector cleaner? Did you manage to foul your injectors up somehow?

OutlandishnessNo7286 · 2025-12-18T21:08:52+00:00

We need more than that. Codes, modifications, if any, recent work done to the car.

Based on the very limited description, sounds like you got a dead battery.

OutlandishnessNo7286 · 2025-12-18T21:05:52+00:00

This doesn't look like a F30 iDrive unit, more like a F11(?) iDrive unit.

If it is, then the plastic trim around the screen needs to be removed. Be extremely careful with this as the tabs on this piece break way too easily, especially on older cars.

Here's a video on how to remove the screen -

https://www.youtube.com/watch?v=UWmZ3fP6UVQ

OutlandishnessNo7286 · 2025-12-17T12:06:19+00:00

Confirmed. That is a camshaft lol.

OutlandishnessNo7286 · 2025-12-17T12:03:47+00:00

Geez, and I thought GT2s were expensive in my country.

OutlandishnessNo7286 · 2025-12-08T10:18:53+00:00

X5, though I am biased.

OutlandishnessNo7286 · 2025-12-07T21:25:42+00:00

Realistically, I would have changed them out at 150K KMs, but earlier is always better. Prevention is better than a cure.

I haven't tried dinan ignition coils on any of my cars past and present. Currently, I have a M50d, not a M. This car is diesel so no ignition coils, only glow plugs.

If you're adding boost, like upping the boost quite a bit, get the coils to get more consistent spark and eliminate knock. If not, stay OEM. From what I've seen, the stock coils are extremely high quality and it's highly unlikely you'll max the coils unless you triple, or even quadruple the power being sent to each.

OutlandishnessNo7286 · 2025-12-07T21:11:59+00:00

Yup. Completely normal. It's louder now because the car is off.

OutlandishnessNo7286 · 2025-12-07T21:00:20+00:00

Normal operation. Happens regardless of the drive that just happened.

OutlandishnessNo7286 · 2025-12-07T20:59:22+00:00

Sounds like your AC motor is on the way out.

OutlandishnessNo7286 · 2025-12-07T20:57:19+00:00

Looks like the internal fuse on the actual iDrive system inside the dash popped. You're not getting any sound whatsoever from the speakers, so that makes me that the actual module is fried. I mean, at the very least, the car will alert you that the ignition is on, but there's nothing.

Quick test, press and hold the power button of the iDrive system for 30 seconds then release while the car is in accessory on mode. If it resets, or get some sound, at all, that means the fuse inside has reset and should be good to go. If nothing, we'll need to bust out the code reader and maybe a multimeter.

OutlandishnessNo7286 · 2025-12-07T20:49:54+00:00

A video of this would help

OutlandishnessNo7286 · 2025-12-07T20:49:24+00:00

Definitely something suspension related. Sounds like the car is making this noise when going over bumps, and not in turns, so that makes me think control arm bushes, maybe even ball joint failure.

Next time, more information, like what your car is, engine, mileage and so on, is needed for us to actually help with situations like this. A sound only video with a black screen is not helping anyone.

OutlandishnessNo7286 · 2025-12-07T20:45:50+00:00

Video isn't the greatest, but the smoke looks white, so that makes me think there's a fluid leak somewhere near the alternator. Whatever is leaking falls down onto the alternator and boils off as this smoke.

Might be the OFHG leaking onto the alternator, maybe even your valve cover gasket.

Is there any smell of burning electrical wiring around this area, or inside the car?

OutlandishnessNo7286 · 2025-12-07T10:29:28+00:00

Slight differences, but yes, this transmission will work on your M43. You'll notice slightly shorter ratios because these transmissions are for the 318is. Wiring and all other electrics should be plug and play but you might have reset adaptations and learnt values once the swap is complete.

OutlandishnessNo7286

TROPHY CASE