This was posted in my Throttle Body Cleaning thread; Mods moved it by mistake to 1st Gen forum.

Well, the new O2 sensor and Vanos connector did not fix the stumble at idle - going to clean and possibly replace the throttle body and install new PCV hose (new diaphragm already installed). New VC gasket 12000 miles ago along with new Vanos solenoids - also burning oil about a quart every 600 - 700 miles. Bad MAF possibly causing low idle stumble?

Love the car but it is an every day commuter and needs to be reliable (especially after all the work done the past 3 years).

Will prob keep her and just send the cylinder head out to be reworked if all else fails - another 1500.00 . In the meantime I will prob just plunk down 15000.00 for a new little gas saving commuter - Ford Fiesta or some such - not a fan of buying new but I'm about ready to let a warranty take care of some of this sh#t.

 

Hello There,

You did not indicate if you are throwing any codes (i.e.. Check Engine Light On).

IMHO - Stumbling/erratic idle is 90% caused by vacuum leak. I have a 2009 MCS and by 126K miles, I'd already replaced entire valve-cover (internal pcv system fails and cannot be replaced, short of replacing entire plastic valve-cover). I'd also had replaced coils. I'd strongly recommend replacing PCV hose (valve-cover to intake) before replacing throttle-body.

Good luck,

W

 

Thank you - will be replacing that. My (usually) trustworthy Mini shop failed to document the codes on the latest bill. I'm getting ready to buy the INPA software and cable from BC Cables as my generic OBDII reader is not adequate for the Mini.

Also, I have been looking for a writeup and/or diagram of every possible N12 vacuum leak location with no luck. At this point I am ready to replace every rubber hose under the hood.