[jeraldthatman]

Hello, so my poor n52 has been suffering for the past few months, and I have no idea why.

I’ve been getting P0175, and here is the freeze data. I was getting P0420 and P0430 a few weeks back and put non-fouler on the O2 sensors so I no longer get those codes. I’ve checked and cleaned the MAF, sea-foamed through the throttle body, and found that the bank 2 catalytic converter is black where it connects to the rest of the exhaust. Also Ive found a small deposit of oil in the first o2 sensor thats on the top of the engine. Inspected the fuel injectors, found that the 5th was a little wet; so i swapped it with the 1st one and it drove noticeably better.


I have seen a big deficiency in fuel consumption, going down to about 17.00 mpg from 23, as well as terribly rough starts in the morning or after the car sits for a while. I regularly drive 60-100 miles 3x a week on the high-way, where there is a noticeable roughness when the pedal is down. Noticeable loss in power as well and a clicking sound screaming from the engine only when the car is in gear.

I put my phone under the hood to get a better listen, but man I’m stumped. A local BMW mechanic said that it is probably my CCV system, but are my symptoms a good fit for the diagnosis?

Side-note** I tried disconnecting the first o2 sensor where i found the oil, drove for a few miles and ended up getting p0015 camshaft position sensor over retarted.

Ive attached the engine sound to clarify a little bit better


Any suggestions, help, similar problems, SOLUTIONS are welcome. thanks

[PhaseP]

found that the bank 2 catalytic converter is black where it connects to the rest of the exhaust

Does black look like soot? You may be leaking exhaust at that connection.

[jeraldthatman]

Originally Posted by PhaseP

Does black look like soot? You may be leaking exhaust at that connection.

Originally Posted by PhaseP

Does black look like soot? You may be leaking exhaust at that connection.

Thanks for the reply, yes it does look like black soot. Should I look at where the exhaust manifold connects to the engine or the connection I referred too.

[PhaseP]

Originally Posted by jeraldthatman

Thanks for the reply, yes it does look like black soot. Should I look at where the exhaust manifold connects to the engine or the connection I referred too.

The connection, since you are seeing the black soot there. You can also search for how to find exhaust leaks.

[gT-BMW]

Originally Posted by jeraldthatman

Hello, so my poor n52 has been suffering for the past few months, and I have no idea why.

I’ve been getting P0175, and here is the freeze data. I was getting P0420 and P0430 a few weeks back and put non-fouler on the O2 sensors so I no longer get those codes. I’ve checked and cleaned the MAF, sea-foamed through the throttle body, and found that the bank 2 catalytic converter is black where it connects to the rest of the exhaust. Also Ive found a small deposit of oil in the first o2 sensor thats on the top of the engine. Inspected the fuel injectors, found that the 5th was a little wet; so i swapped it with the 1st one and it drove noticeably better.


I have seen a big deficiency in fuel consumption, going down to about 17.00 mpg from 23, as well as terribly rough starts in the morning or after the car sits for a while. I regularly drive 60-100 miles 3x a week on the high-way, where there is a noticeable roughness when the pedal is down. Noticeable loss in power as well and a clicking sound screaming from the engine only when the car is in gear.

I put my phone under the hood to get a better listen, but man I’m stumped. A local BMW mechanic said that it is probably my CCV system, but are my symptoms a good fit for the diagnosis?

Side-note** I tried disconnecting the first o2 sensor where i found the oil, drove for a few miles and ended up getting p0015 camshaft position sensor over retarted.

Ive attached the engine sound to clarify a little bit better


Any suggestions, help, similar problems, SOLUTIONS are welcome. thanks

I have the same car, same issues as well. i replaced both bank primary o2 sensors, entire ccv, cleaned maf sensor, ordered new connectors for the maf from a write up from a member here, replaced some coils, changed the oil, reset adapations and some other things. i wanted to replace my air filter too but its still clean. still no change. at this point im just throwing money into it so i gave up. im starting to think its the maf sensor it self. does anybody know how to test it? hope you find the issue.

[jeraldthatman]

Originally Posted by gT-BMW

I have the same car, same issues as well. i replaced both bank primary o2 sensors, entire ccv, cleaned maf sensor, ordered new connectors for the maf from a write up from a member here, replaced some coils, changed the oil, reset adapations and some other things. i wanted to replace my air filter too but its still clean. still no change. at this point im just throwing money into it so i gave up. im starting to think its the maf sensor it self. does anybody know how to test it? hope you find the issue.

thanks for the info, I was planning on getting some maf cleaner later on tonight, ill keep you updated on any changes.

i also cleaned the solenoids and found some of the connectors were dirty....

do you also have the noise when accelerating around 4k??