Help car running like shit

[eclaytor]

I have had this rough idle issue for a while. It was solved the first time by replacing the spark plugs and not driving for two weeks. When i say rough i mean 500 to 1000 rpm. Since i have done a carbon clean and changed to R8 coils. It has been driving great for about a month. On the way home tonight i was driving hard and i suddenly felt the rough idle. I hooked up my torque app with the obd reader and got all the P030X codes plus P2177 and P0506. I would lean torwards a vacuum leak but dont know where to start. Vacuum was surging with the idle. Thanks for any help.

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[van462]

Unclip the hose from the Intake manifold to the PCV. Cover the intake manifold port with your palm. If the idle smooths out then this is where the extra air is coming from. Also look where the vacuum actuator for the air flap vane connects to the Intake manifold (firewall side) The plastic plug here sometimes fails and pops out. Usually it comes with a flapper out of position fail associated with it.

[Dr. Awesome]

I have a similar issue, I initially thought it was my engine mounts failing and transferring more engine feel to the car frame, but I'm thinking it's something PCV related. I did the PCV, R8 coils, and plugs and it didn't really change anything. Got worse this winter, so I will be continuing to troubleshoot. I did have my hose pop off once (after I did the PCV, didn't get it snapped in all the way) and the car felt like it was about to die, and this feels a little like it, but to a much lesser extent. If I find a cause I'll let you know.

[eclaytor]

Thanks guys. Ill give this a try before i go to the stealership.

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[eclaytor]

Unclip the hose from the Intake manifold to the PCV. Cover the intake manifold port with your palm. If the idle smooths out then this is where the extra air is coming from. Also look where the vacuum actuator for the air flap vane connects to the Intake manifold (firewall side) The plastic plug here sometimes fails and pops out. Usually it comes with a flapper out of position fail associated with it.

I just pulled off the engine cover to see if I could find the leak and I saw that the hose on the PCV side had come disconnected . The clip seems to be fine so i'm a bit baffled. Problem solved. $$$ saved. That could have been a $500 bill from the mechanic. So with all that money saved, I should by a set of coilovers :) Thanks van462

[van462]

Glad to hear it was an easy fix.