[RayLivingston]

While changing the plugs on my '07 335i, I noticed some critter has been chewing on the wiring (again!).

But I have no idea what the wiring for. The wires in question are at the left-rear of the engine, up against the firewall. There is about a 1" diameter plastic pipe tee'd onto the intake duct, and running to the RH side of the valve cover to near the front of the engine. Maybe part of the breather system?? The sensor the wires connect to is right where the 1" pipe connects to the inlet duct. What sensor is that??

An image can be found here:

View post on imgur.com

Regards,
Ray L.

[TheMidnightNarwhal]

That's the PCV breather heater.

[RayLivingston]

Never heard of such a thing! What exactly does it do? When is it used?

Regards,
Ray L.

[nsjames]

Originally Posted by RayLivingston

Never heard of such a thing! What exactly does it do? When is it used?

Regards,
Ray L.

it heats a small element at the intake manifold where the PCV drains to it to keep it from getting frozen up and blocked.

and if you have rodent problems go to TSC and find the bags of shavings covered in peppermint oil. They're for keeping rodents out of tractor cabs during the winter.

toss a few under the hood, or under where you park.