How do you replace the thermostat located on a 1997 Volkswagen?

Answer 1

I have recently replaced Thermostat on my 1999 New Jetta GLS. Here is what I did and the replacement was successfull.

First, the coolant has to be drained completely. Locate the drain at the bottom left side of radiator and drain the coolant from radiator. Then drain the coolant from the engine block. I did not do the second drain and got about 1 pint of coolant spilled during the thermostat replacement. Detach the hose from the thermostat housing cover at the front of engine block. Pull the metal hose clamp back over the hose. You will need wide angle pliers to loose the clamp. Reattachment during reinstallation will be more difficult. Remove the bolts/nuts and detach the cover. You will need 10mm size wrench (or Allen wrench) to do it. I got very anxious when I find out how inaccesible are the nuts. The Allen wrench would work better if I had one with the right size. Use screwdriver to gently remove the O-ring. It is recommended that you get a new O-ring. Remove the old thermostat, place the new one, then O-ring and the remaining steps are reverse of installation. Remember to close the coolant drains before refilling the cooling system - the old coolant can be reused. The coolant must be added gradually. The engine should be turned on for a while to allow the coolant to reenter all the space in the engine block and radiator.