I've never done much work on my car but finances makes it a must. I have a 2000 C70. When the check engine light came on I took it to a friends and used their meter and got a po128 code friends husband showed me where thermostat is, but he just had back surgery and I need to do this myself. Do I have to drain coolant? Can't I just undo the two screws and pull out the old stat. and put the new one in?

 

Normally yes. Then top off coolant. Drive or let vehicle idle until thermostat goes thru the open/close cycle. Should check coolant level next couple of drive cycles or next couple days. Being a 2000, hope you know when the coolant was last changed. You or an auto parts store can check the coolant condition with a hydrometer.

 

I normally put a large pan under the car and catch whatever leaks out and add that much back in. Don't add tap water, add the proper coolant mix back in.

What is the code? I never heard of a code that tells you to change your thermostat.

 

Get Xerex G05 coolant at NAPA.

 

I have a 1990 240 wagon. Can I replace my thermostats same way, and where would it be located? Thanks

 

Generally the thermostat is located on the block at the end of the upper radiator hose. Follow the hose to the engine and you'll see a roundish cap (usually held on by two bolts). The thermostat is under that. Note the orientation when removing and use a new rubber gasket. No sealant or gasket is required for the housing itself. You may lose a small amount of coolant when opening so have a pan ready or drain off a bit through the stopper at the bottom of the radiator. When refilling, make sure you use the right kind of coolant (ie green vs orange vs yellow etc). Owner's manual should cite what is proper for your model.