small exhaust next to driver side
 

Can anyone tell me what the heck this is? I was driving my 3.0D in cold weather and cut the engine after parking. I notice a small humming sound and when I got out of the car, I saw some smoke coming from a small exhaust underneath the driver side. Its stopped after a minute or so. Any clues???

It's your auxiliary heater! Great feature - wish we had it in the U.S.!

sorry for being a noob but what purpose does this serve?

It`s great. Basically the diesel models dont warm up fast enough or hot enough so they have an additional little fuel burning engine. This is a webasto thermotop, controlled by the car electrics - on and off when needed etc.

You can buy a remote control kit from BMW which allows YOU to pre warm your car from your house though. I bought and fitted this and it`s one of the best mods I ever did.

Read this thread. http://www.xoutpost.com/x5-e53-forum/...hlight=webasto