Cooling system

My temp red warning light comes on in my 2000 VW Beetle, I changed my thermostat, Light is still coming on, what do I check next?

I'd look to the electric fans. test them and make sure they come on. If they don't they could be fried, or the sensor that tells them to come on could be fried.

the fans work, where is the sensor at.

not sure about the sensor. It would be somewhere high up in the block/head screwed into a water passage.

There are other things to check. Is there prenty of coolant? How many miles since its been flushed? Are there bugs and stuff on the front of the radiator? Are you sure all the air was burped out after the stat change?

Its either truly overheating or the sensor is wrong and it THINKS its overheating.

Maybe the best thing at this point is to get a Bentley or Haynes shop manual for your car. That would show the location of the sensors and have a wiring diagram that would help you isolate the locations.

how do you burp the air out?

if its a 2.0L, they have a habit of shattering the waterpump impellor, they are plastic.

If it overheats very quickly, thats probably the problem.

you can verify by pulling a hose and run the car. If the pump is working, when you rev the motor, you will get a lot of coolant flow. If its broken, there will be no flow no matter how much you rev it.

Most of the aftermarket waterpumps use cast iron impellors. Don't get a stock one