Hey need to replace the thermostat on my parents van, read the procedure from the haynes manual seems pretty straight forward, but when i go to replace the thermostat is that all i replace? or do i have to replace the housing it sits in also?

 

Replace the thermostat and gasket, not the housing.

 

hey just one more quick question. Im doing this on my parents van, awhile back i think they blew they're head gasket by driving 6 hours with only 2 L of oil. Since than when they start the van it blows white smoke and smells like burning oil. When i replace the thermostat im going to use a chemical flush to clean the system, could this show some hidden leaks that are clogged with gunk right now? the van has 210000 kms and is still original coolant from what they say. I dont want to fix the thermostat and create a bigger problem, should i just skip the chemical flush?

 

You can flush the cooling system without a thermostat, install the new thermostat and new cooling liquids after flushing is complete. The white smoke is from oil getting past the rings on the pistons and getting burned and passing thru the exhaust.