[DreamM235]

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Hey Everyone,


Long time lurker here, hoping to get some advice on one of my first issues I'm having with my 2016 M235xi.

Background:

I bought this car brand new and I am the only owner. I have never modded or tuned the car always kept it stock just did lots of maintenance. Regularly done oil changes every 5K miles, never tracked, never pushed hard just nice spirited driving in sport mode. Always put Shell 93 gas, always warmed up the car before rolling off in eco pro mode, and also have a P3 guage to tell me the temps oil/coolant. I've done spark plugs at 45K, transmission front and rear diffs fluid drain and fill at 45k, tires Michelin AS3+ since 2020, and replaced new battery at 45k as well. The car currently has 63K miles. Car has always been garage kept, never driven in winter.

Problem:

Past 2 weeks i've noticed the car just feels off, doesn't have that fun nature drama. I noticed as I drive in any mode it doesn't have that solid gear shift noise as the 8 speed goes through the gears, its just very muted. Then I noticed that I don't hear the exhaust much at all as I drive.
This is the stock exhaust that comes with the car and it always made the "pops, burbles, crackles" in sport and eco modes after the car is warmed up nice and driven. I did a 80 mile drive last night and any mode I use, no noise from the exhaust. Its too quiet, and it really ruined the thrill/fun of the drive especially in sport mode when you WOT or coming out of a exit ramp and get those bangs and pops through the gear shifts. Letting off the gas there's no noise either.
The car drives fine, no power loss or anything, no CELs, but for sure not much noise from the exhaust, no noise on gear shifts, and sometimes i feel like there's a artificial load on the car as if I have to press the gas just a bit more then I normally would for any driving. My last oil change was this June and was driving great since, except just this past 2 weeks. I thought maybe the exhaust valve is stuck, but i checked with a flashlight and its open. I revved it while parked and it made the pops and burbles, just doesn't do it while I drive it.

I'm considering starting with just ecu reset by removing the terminals for a few hours. If it doesn't work worst case take it to the dealership and let them diagnose. Super stock car and just all of a sudden this happened.

Hoping someone has a clue what this could be, appreciate anyone's input! Thank you

[BringBackButtons]

1) good maintenance regime.
2) have you reset adaptations
3) you mention no maf sesnor clean nor 02 sensor replacement, maybe you did, maybe not, but reaetting driver adaptations is the first id try

Then, i would examine air filter and clean maf. Pops and burbles are unburnt fuel ignition post cynlider (for most part) and is tougher on cats, and 02 sensors.

Just from my previous zf8 n55 engine experience, take as you will.

[Shovelman]

Well, as we share the environment I'm ok with your reduced noisiness

[DreamM235]

Yea not a fan of the extremely loud exhausts with no cats causing gun shots, only at events it’s fun lol.

Since last week I’ve replaced the air filter, cleaned the MAF with CRC MAF cleaner, and did the throttle adaptation reset. No hesitation or throttle lag now but still no pops or crackles.

I then went to the stealership and requested full diagnosis. They found no codes, nothing damaged, all parameters of sensors within spec and voltage, no leaks, fuel is clean and good quality too they said. They said it drives fine but I explained all my symptoms but no luck.

Only thing I haven’t done is full ECU reset by removing the battery terminals overnight.

The car is bone stock I’m extremely puzzled why all of a sudden I lost my stock burbles in all driving modes of the car when it shifts or let off the gas. Doesn’t even do that nice build up as you wind up and the gear changes either, just a very dull muted experience. Only when you put in park and rev it makes burbles but not as you drive. Makes me want to just sell the car now

Anymore ideas or thoughts on the issue?

[Fraysa]

I think it wouldn't hurt to hook up BimmerLink or some scanner to see any faults perhaps.

[DreamM235]

Just got the OBDLink CX and got the 2 apps bimmerlink and bimmercode.

Turned on the car and got below errors when running memory scan.

Here's the codes:

CD0487 - Sync process failed, cc was not synced when memory lock release
108001 - Intake air temp sensor, electrical: short circuit to positive, 102427km
480112 - driving dynamics switch - comfort - deactivation of handbag function, 85083km
480134 - SBS function direction of travel unsafe with vx greater than 2 m/s, 89681km
804197 - Output TFL_R has a short circuit 92977km
8041A8 - welcome light repeat lock active
801A55 - theft alarm system: detail in memory 87003km
E12C1A - Interface CAS / FEM / BDC ( central locking and flap status 0x2FC): signal invalid 78893km
B7F668 - COMBI system time reset 91197km
03178A - SIF: General network errors
B7F343 - Backup battery: before end of life 85928km
E14600 - Ethernet: physical error (link off) 83892km
E1C440 - reset 100234km
E2EC08 - signal (0x330) received invalid: distance_km
8011C1 - external FBM and audio control panel: key clip detected
E7145C - Message (STAT_ZV_KLAPPEN, 0x2FC, FA): ST_CLSY 78893km


the most interesting code looks like 108001 - Intake air temp sensor, electrical: short circuit to positive, 102427km which is right when I started noticing this. When googling this it says related to communicating air/fuel ratio mix to ecu, would this explain the missing burbles? Not sure if this is the MAF or MAP sensor or something else called intake air temp sensor

Also how the hell did the stealership not detect all this??

[Shovelman]

Maybe it was never meant to make all that racket and finally healed itself with some kind of automatic download.

I'm more intrigued by 480112 ....deactivation of handbag function. I think this allows you to drive with a purse on the passenger's seat without buckling it in.

[BringBackButtons]

To the op, yes, iat will also pull timing and cause baseline tuning. And no, iat sensor is not the same as maf nor map or tmap sensor.

Id be interested to see if your car returns to previous after replacement.

[DreamM235]

Do you know where the IAT sensor is or the part #?

Everywhere I've read they said IAT is integrated in either the MAF or MAP sensors. On FCP Euro or getbmwparts I see nothing for IAT sensor for 2016 M235i. The M240 and B58 motors i see option for IAT sensor but not seeing for N55 motors

[BringBackButtons]

Hmm, i think i had my brain confused. I know there is a seperate sensor for the Ambient Air temp in front but thats for ac related, my error, not intake air sensor.

It does appear that the tmap sensor on our charge pipe, the MAF sensor and MAP sensor on our manifold all have temperature recpeticles built in. You could try reading all 2 post maf sensor to see what its reading to help narrrow down. If those two are consistent, then its the maf. If one or 2 are significantly more than each other, id error on the one reading higher (map or tmap) needing replaced.

My foxwell reader would let me on my e70 x5.

[BringBackButtons]

https://f87.bimmerpost.com/forums/sh....php?t=1791017

Not necessarlily the same, but mostly. Id go for seeing about disconnecting, cleaning, and reinstalling sensor on our charge pipe.