Hi, I have a 2008 MCS hatch that I purchased a couple months ago. Over the past few weeks it's been giving me a lot of issues that I'm having trouble diagnosing. Maybe like 3 weeks ago I was driving normally and the half filled engine light came on in the center of my tach. I brought the car home and ran the codes and nothing came back. I did notice that the car was running fairly hot, I ended up replacing the thermostat housing and it ran cool again and didn't give me any more problems until about a week later, same thing I was driving normally and the car went into "limp mode" again. I took it back home and read the codes again but still nothing. There wasn't anything obviously wrong with the car to I cleared the codes and the engine light disappeared from my tach. A few days later the limp mode came back again, I cleared it again but when I went back out and I felt like the DV wasn't as loud as it was before. still louder than it was when it was in limp mode, but it seemed quieter. I drove around with the OBD reader plugged in to see how much boost was being made, in 1st and 2nd gear no more than 7-8 PSI. In 3rd to 6th the boost seems to build very slow, and as soon as it hit around 10.5 psi, it went into limp mode. Even if I try to get it to over-boost i can't get more than around 10 psi in 3rd to 6th without the car going into limp mode. and I still can't read any codes. The engine itself runs very strong, no oil leaks. I took out the DV and visually inspected it and it looked brand new. No boost leaks that I could find. The car has had a small exhaust leak right at the bottom of the DP since I bought it, I thought that somehow this might be causing the issue so I ordered a DP back exhaust because I wanted to upgrade from the stock one anyway. But yesterday I was driving the car in traffic and after idling for about 5ish minutes, I hit the gas and a large amount of blue smoke came from the exhaust, it cleared up in about 10 seconds but it was a pretty big amount. So now whenever I let the car idle for a while and then give it gas i'll get the same result. I brought it home and started messing with the engine and checked to turbo for shaft play just as a guess, there was very little side to side play, but there was an alarming amount of axial play in the shaft. No oil in the housing that I could see but the axial play is pretty bad and I'm convinced the turbo is probably junk. So right now I'm planning to replace the turbo cartridge, and the whole exhaust all together but I just want to know what could cause this as I don't want to do all this work to ruin another turbo. I've read about oil soaked cats can cause the thrust bearing but I'm not sure if thats the only issue. Thanks.

 

When you say OBD reader, is it one specifically designed to read BMW error codes or is it a standard OBDII diagnostic reader.

Each error code the ecu is programmed to look for has a number of times it must occur before flagging and what is also called a heal time.

For example an improperly working diverter valve will trigger the half engine light (BMW code 028AA) which will be stored in the ecu permanent fault memory. After a short period of time with normal driving (heal time elapsed) the half engine light will disappear but the error code can still be read out with the proper reader. However, there will be no corresponding P code stored that a standard OBDII reader will display.

 

Its an OBD link reader so I'm assuming thats just a generic one, where can I buy a BMW specific one?

 

Most all NAM vendors carry them but you can also purchase various apps for your phone and use a bluetooth or wifi obd adapter. I use Carly for BMW for quick diagnostics.