MAF sensor and charge pipe leak.

[PhillyfaanM3]

Sharing this story in the event others are experiencing similar issues. My car is a 2011 135i (N55) w Dinan Stage 3, intercooler, oil-cooler etc., and currently with 28k miles.

So...A few weeks back, was driving the car for about 30 mins or so and noticed my coolant temp was climbing really quickly & going above the safe zone (250) and my P3 gauge flashes "STOP" It also flashes code 29d0.

Prior to that I was experiencing these weird fluctuations at idle where the RPM's would be hanging right below 1k and then drop below 500 & then back to 1k.

So I take to the dealership & they start diagnosing it, MAF sensor needs replacement, 1 charge pipe replaced (leak along the long part of the tube). Decided to remove the BMS intake & go back to stock with a K&N drop in.

The car is back & running great again. Thanks to the team at Thompson BMW (Doylestown PA) Matt Bean from their BMW Performance service dept. & his Techs, these guys always treat me well & take utmost care of my cars.

They did all the performance work (Dinan, suspension, exhaust etc.) & wouldn't take it anywhere else.