Z4 How to change 2003 Z4 thermostat - Help!

2003 Z4 E84, temp guage shoots to far right over-hot for a second then retrurns to normal. Engine check light is on as well. Heater only blows hot air intermittently but usually just cold even though temp setting in the cab is all the way hot. I figured it was time to replace the thermostat but have not yet done this on my Z4. Need your help, pics, videos, etc.

Couple of immediate thoughts
1. check your coolant level now
2. sounds like air in the system

Hi Zeeboy, thanks for posting.
Coolant level good. Not familiar with issues of air in lines? Please explain.

A quick search will give you a lot of info, here are a couple links about bleeding air to get you started.

http://www.bimmerfest.com/forums/sho...air+in+coolant

http://www.bimmerfest.com/forums/sho...air+in+coolant

Originally Posted by ZEEBOY

Couple of immediate thoughts
1. check your coolant level now
2. sounds like air in the system

ZEEBOY, sorry for the delay in follow up. Many thanks!! You were spot on with the air in the coolant system tip. New to BMW maintenance and was not aware of this problem even existing. But it was exactly that, simple to remedy. Thanks for being out there helping us newbies!!
Pete82

These cars have a fail safe thermastate. Once the thermastate reaches a certain amount of high psi it is forced open. This explains the engine overheating and then cooling down a bit. I would replace the thermastate, water pump, and exansion tank at the same time as these typically all fail at the same time.