I have a 04 mini cooper s with JCW tuning package. Has 103 k on it. SES light popped on for p1237...manifold pressure (vac leak) but goes on and off and car pulls hard.

I ran seafoam through gas tank, bit in crankcase(I'll be changing oil soon), and 1/2 can in Pcv hose. Car smoked like it should, however now car wants to stall when I have it idling in neutral. Runs strong in all other gears and rpms.

I changed plugs, cleaned tmap and map sensor, and disconnected battery. Idle still struggles to stay running in neutral.

Any other areas to clean/check?

 

And I looked at my vac lines and didn't see any cracked or disconnected

 

intercooler boots?

 

Would a hose loosen while sea foaming? It idled perfect at around 900rpm before this

 

Well I have also now cleaned the throttle body, it was pretty clean already.

I discovered a few things:

1. When I remove the hose connected to the pcv, it idles smooth as butter. I pulled the pcv off and cleaned out with throttle body cleaner. I could hear the internals moving freely inside. Reinstalled, reconnected the pcv hose, and idle became sporatic and wanted to stall again. Maybe the pcv is bad even though i can hear internals moving??

on the stock intake snorkel it's missing a clamp holding the rubber elbow to the black plastic piping. Also there is a piece of red duct tape covering an opening on the bottom of the plastic piping....im guessing something removed from the OEM airbox when the ALTA intake was put in.

All aftermarket mods were done before I bought the car.

Can I run the car without having the pcv hose connected to the valve? Is there a better long term solution? Any more ideas?

So recap*** Car idles perfect and revs without having hose connected to pcv valve....as soon as i reconnect, idle is crap.

 

late but

in my experience there is one 'screwed my car up' for every 'helped my car' post if you expand your search beyond one make/model.

drive it for a while and you'll probably clean this crud out.

I'd also run top tier fuel

 

Is it okay to run the car with the PCV hose disconnected from the PCV valve? Car idles perfect when it's disconnected. I removed the pcv valve and cleaned it, and i hear rattles, so im assuming its okay but i ordered a replacement anyways. Im confused as to what else to check.

 

it's okay to run the car without the pcv valve hooked up for a little while. I've done it for more than a month and my car was fine, it just won't run as good as it should.

I'm guessing the reason you're experiencing this problem is because the seafoam sucked a bunch of gunk that got stuck in your pcv valve clogging it.