X1 | Limp Mode, No CEL, No Codes

[Giniius]

Hello all, first post in here so please take it easy on me (:

A few months back, my car stalled on a in city drive and it ended up with a CEL, as well as Limp mode, the car would start and drive after 30 minutes or so of waiting, but only would for 5/10 minutes or so.

After replacing the water pump, the car drove for another week, then the issues came back, and it spent a month in the shop. The Valvetronic servo motor, ECM, and the high pressure fuel pump, gaskets, and spark plugs all got replaced for big money and the car was fine but had a weird idle and rumble that I couldn’t quite place.

After about a month or two, the car has once again entered limp mode while driving, this time with no stall, and managed to “limp” me home where it’s sat since. The car starts as it should, but is still in limp mode. There is no CEL, no codes off my scanner, and so I’m a bit lost on what it could be at this point.

For some context, in the last few weeks, in longer drives of 30 minutes or so, I’ve had some smoke coming out of the car with a burning smell that we attributed to a seized calliper that we fixed, and after that was fixed was when the limp mode became a problem. The car is also due for an oil change at 215.5kms, im currently sat at 215.9kms, would the oil needing to be changed cause the problem?

Basically, I’m a bit lost without codes, or a CEL, and unsure where to even think about going with it before I see my mechanic and spend even MORE money.

I’m looking to get rid of the car at the end of August, just need to get it in sellable condition.