Cooolant, do you need to flush?

[DavidGrimshaw]

Hi. Do not fret, I did a search of this forum and did not see an answer. I have a 2003 Toyota Camry with v6 engine. I am scheduled to change the coolant and intend to do my own maintenance from now-on. The Gregorys/Haynes manual gives a fresh-water flush procedure for the drain and flush of the cooling system. Do I need to flush the system to renew the coolant or is just draining it satisfactory? I would like to avoid taking out the thermostat which is part of the flushing procedure; this seems to be a big job for my car.

 

[Burnerman]

You'll get a few different opinions on this I guess, but it really depends on what state the old coolant is in when its removed.
If there's lots of rust in there then a flush has to be a good idea, but if its fairly clean just pop the hose into the radiator top and let it run from the bottom....it won't touch the engine internals though. Remove the bottom hose from the engine and hold it down low.
Another method is to refill with clean water, drive for a bit and then drain that out.
Its a good idea to release one of the heater radiator hoses too - this will remove most of the coolant thats trapped in there.
John

 

[Avocet]

As Burnerman says, I wouldn't bother unless what comes out looks like oxtail soup! You could always drain it, as Burnerman says, re-fill with just water, and run the car until the cooling fan cuts in. That'll make sure the thermostat is fully open and stuff that was stuck in the block and heater matrix gets diluted by the new water. you can always do it more than once until the stuff that you're draining out looks reasonably clear.