My 2001 2.0 is over heating after a new radiator( replaced because of a crash) and a new thermostat.the fans are working,it has anti freeze.any other ideas on what it could be? Air trapped in the system?
It could be an air pocket or a bad water pump. I alway drill a small hole in the body of the thermostat to avoid air pockets.
The water pumps from VW hav a plastic impeller that tends to come apart. Look at my post "Water pump advisory" and you will see what I mean.
I got home n noticed the resevoir was empty so i filled it to the full line and let it run with the cap off.i watched it untill the fluid stopped letting out air bubbles and now its been driving fine...so far.
The reservoir is the highest point in the coolant system so all bubbles will go to the top and purp out you just need to keep an eye on the level and keep adding coolant until it no longer go's below the reservoir limit lines. The temperature light was probably flashing meaning it was low on coolant at the reservoir and not really an overheating engine, which could lead to an overheating engine if not taken care of.