I have a rough running/stalling condition develop in our 2009 Clubman S, and I smoke tested the intake and discovered a massive airleak between the MAF and the plastic intake plenum. It appears that the MAF is held to the plastic intake plenum by screws that thread into some factory tape or coating that just pulled out. As a result I can’t tighten the MAF sufficiently to seal the rubber O-ring.

Is there a common fix to this? My first thought is to install a helicoil into the plastic of the plenum so I can tighten down the MAF, but I’m not sure if a helicoil will hold in plastic. Perhaps coat the outside of the helicoil with some plastic-friendly epoxy or JB Weld? Or try to seal the o-ring better, perhaps with some gasket-maker?

 

I would be tempted to use inserts meant for wood, rather than a helicoil.
https://www.rockler.com/hardware/fas...readed-inserts
Helicoils exert a radial, outward force on the threads you drill into the base material...
Maybe a timesert?

But is there enough material there to drill out for something like this?
Warm it up well before installing!

I pulled the intake off a car at the junkyard to find it'd melted onto the head...

t

 

Thanks, I’ve thought about the wood inserts, that might be a better way to go. I could even try heating the inserts with a torch before installing to make it easier to go into the plastic.

I also just ordered some larger (1/4”) self-tapping screws for plastic. That might be a simple option. Either way, it’s a silly joining method, using self-tapping screws to clamp down on a stiff O-ring that seals the maf.

 

Agreed. Plastics are the new wonder material of the modern age... until they aren't.

And the MINI makes MAXIMAL use of the plastics.

t

 

A quick follow-up: the EZ-lock inserts for wood work great for plastic. I did a test install on an old plastic cutting board and discovered that the insert driver doesn’t have enough engagement to sink all the way into plastic and it stalls half way. But a little heat applied to the insert just before application works great. A great fix for "self-stripping” screws in plastic.