OK, so what happened today (and still makes me a little paranoid when I think about it - so please comfort me if you see it technically appropriate) is this: after I hit a mileage of 10,000 km which I consider high enough to treat my engine fully broken-in. OK,OK, I know; - I never babied this car since day one, but occasional rpm burst were short and never with the needle in the red zone of >6500 rpm, and above all: only with the oil in optimum temperature - so please do not derail this topic by starting discussion on breaking-in methods :)
I was busy (and must admit a little distracted) by my efforts to make all my devices connect and work properly for using some Android Apps (ranging from a simple and free 0-100 km/h accelerometer, through Torque to Dashcommand - and the devices were, as you already guessed: my phone, the ODB II BT dongle, and the XGPS160 10 Hz dual GPS receiver I use to make readings based on the GPS refresh speed more precise). Mind you - I have only just left my garage, and didn't make more than some 5 km with some additional time standing pulled out as I'm using a new Android smartphone that wan't paired to all the devices before; I was so busy doing it that I'm really unable to remember now how long it took altogether - one is for sure: good several minutes, and I never switched the engine even a single time... So I sincerely hope the oil temperature was still rising, but cannot be sure what exactly temperature it was at when IT happened:
- Instead of first running Torque Pro or DashCommand where I did define the oil temp. gauges, I wanted to check functionality of a new simple app I installed just today for GPS-based measurement of the 0-100 (0-60) time. All this far from routine activities made me forget about the oil temperature! I put my car in Sport+ mode (I have Sport defined as acting on both the chassis and drivetrain), made the new app ready, and pulled away at WOT!
Sorry for the long introduction - now I finally am going to say what worries me so much: the engine achieved its highest RPM so quickly that I didn't even have time to move my attention (and eyes) from the phone display to the tachometer, so I'm even unable to say whether it was 6,500 rpm or more... But it must have been more (luckily for jsu a second), because I can still here the unusual sound the engine made during that second. Of course I cannot describe it, but one thing is for sure: even though such short burst of max rpm did happen in this very car before, but:
- I never heard this sound when it happened
- ASAIR, at those previous occasions my stick was in D position so the 8AT upshifted in no time...
This time however, I was in Manual/Sport selector position... So, finally the question to all of you knowing the M235i in general, and the N55 engine in particular:
1. Considering the oil was maybe at some 60 C, could anything that would ruin my strategy of breaking-in this engine happen? I don't assume any direct damage, as things like this happen - for instance when a manual transmission user makes a mistake...
2. What do you think was this "unusual part" of engine noise I never heard before, even though I did hit the maximum RPM at WOT many times before (the difference being that my 8AT tranny upshifted immediately)? I'm hoping this has just been some turbo noise at WOT I never happened to hear before in this particular car - but I'm freaking at another possibility: to high RPM for the engine oil temperature :( What is the probability of the latter?
3. I learnt from my experience with the first generation GSM gearbox I had in my old good E46 330i that even in manual mode, the tranny WILL upshift in situations like this, just to protect the engine - but my today's experience would indicate it's NOT the case with the 8AT M235i. Can you confirm or deny this?
Sorry again for a long post, but - unless some of you guys comes in and say nothing really bad happened, I'm afraid I won't sleep well in the night... So please comment - and do not spare me, just say what your technical knowledge and experience with those engines tell you. TIA
Piotr
Hit too high RPM due to my error, and with oil temp. too low
