Hello.

I own a 2010 R56 JCW that I recently installed 2 catch cans on. I installed the Turbo side Catch Can and ran it for a couple of weeks with no issues. I recently added the passenger side(US) catch can and the car has a massively stumbling idle.

In troubleshooting this, I removed the connector for the MAF sensor and the car returns to smooth idle. I removed the MAF sensor and cleaned it by shaking it in a ziploc bag with some 90% isopropyl alcohol and let it dry overnight. This had no effect and the car still has the massively stumbling idle/almost stalling when it's connected.

Here's a video demonstrating the symptoms. Any ideas as to what I should check next?


Thanks in advance.

 

You most likely have a leak on your passenger side catch can. If you watch how to seafoam a n14 you will see that once that is disconnected it starts to run rough. I would start there. You can block off the passenger side pcv and keep the catch can on the intake or driver’s side. I’m running this way, 15,000 trouble free miles.









https://www.ecstuning.com/b-genuine-...11617596034kt/

 

Thank you for the input. So typically that PCV hose on the passenger side is connected to the intake manifold beneath the noisemaker. If I blank that hole in the valve cover, what happens to hose going to the intake manifold? Do you plug it as well?

 

Yes sir, block it off both sides and pull the tube out. All done. That link should be for 2 plugs.

 

Thanks a bunch. Ordered them. Got a MAF Sensor coming as well.

I removed the intake manifold pcv hose already. It was cracked. I ran a regular fuel line hose between the fitting on the bottom and the catch can, but I can clearly hear a vacuum leak at the valve cover connection. It just seems really odd to me that it runs 100% smoothly when I disconnect the MAF Sensor and chugs horribly as soon as I plug it back in.

Guess I'll check the Vanos Solenoid after I swap those parts one at a time.

 

Honestly before you dump anymore money, the MAF might not be needed, plug the pcv. Once you have it plugged, then start the car and you should be golden. Don’t over think this too much, start there. I bet that is your issue.

 

Jason,

Thanks for the suggestion. I installed the plugs from ECS, buttoned-up everything with a new Turbo Inlet Tube as the old one had cracked at the turbo inlet, cleared codes and it's back to running as it did originally. I need to reinstall the one catch can, but didn't want to hack into the brand new Turbo Inlet Tube yet. Gonna run it tomorrow to check that it generates no codes and then return the MAF I bought if it all works out.

From one Jason to another, thanks for your suggestion.

 

go with an oil catch can on driver’s side and you will be fine. I’m glad so far so good.