Changing themostat on a 98 jetta

change the themostat
and clear code with computer

Sounds like the thermostat needs replacing... should cure the issue...

Leajking hjead gasket most likely.

run fault codes and look for a faulty fan/ temperature sensor

did you put right.did you bleed, air lock,coolant.

ARE WE TALIKING ABOUT THE KEY CYLINDER OR THE ELECTRICAL SWITCH?

did you changed the themostat ? sound like you have a bad themostat. good luck.

must have blower on

If it overheated without being low on coolant the first time you may have a themostat sticking. But I would start with a check of all the hoses for cracks or loose clamps. Also check leakage at the front of the motor from the water pump. It's hidden behind the a/c compressor but you should see splash marks on the hood if it's leaking there. For good info on how to fix it yourself try www.saturnfans.com. There are a lot of good tech tip articles for the S series cars. I lost a water pump pulley at about 90,000 overheated five times getting home. The car now has 230,000 on it and still going strong.