Volkswagen Repair: overheating, radator, thermostate

Question
I have 2000 jetta with a 2.0 engine.  I first had a leak at the temp housing unit on right side of the engine..  i replaced the plastic unit
and changed the thermostate ... but it is overheating like it did when i had the leak..the upper radator hose is hot but the lower is cool until the engine
is stopped then they both become hot.

Answer
Most likely you need to burp the system cause you got a an air-lock.  Its normal for the lower hose to be cooler that means the radiator is doing its job, but it shouldn't be cold. The way I like to burp my VW is I stick a slotted screwdriver inbetween the upper rad hose and where it attaches to the radiator.  Start the car and as its warming up you'll start to hear air escaping where the scrwedriver is, after a couple minutes the water will gurgle up and start coming out.  Pull out the screwdriver and put on the clamp, should be fixed. Also as a side note make sure you put the thermostat in facing the right way.

Good Luck,
Ryan