Check Thermostat and Coolant Change

[TigerVX]

I'm going to change the coolant on my VX next week and I have a few questions.
1 - Is draining the existing coolant via the lower hose and knock sensors, then flushing the system via the top radiator hose the best way to do it?

2 - Does flushing the radiator that way also flush the heater core?

3 - Does the thermostat need to be removed to check if it is still good or are there other ways to know if it's buggered or not?

Thanks.

 

[accentstencil]

Yes that is correct. But you temporarily put the knock sensors back in while flushing, then remove them again for the final drain. It will flush the heater core providing you have the heater control set to hot. Make sure you use a coolant that contains ethylene glycol and not an inhibiter. I use Tectaloy V Plus which conforms to GM-H factory specifications for the Holden Commodore V6 engine. It's not cheap but then neither is the holden coolant. I used to use Nulon but was advised against it.