Hello, I recently drained my 2005 Toyota Camry's green coolant from the radiator and the reservoir. I then refilled it with red HOAT coolant just as Toyota recommends. Will the remaining green coolant in the engine block cause problems because they are not supposed to be mixed or is the residual amount not significant? Thanks!
I don't know if mixing those particular chemistries will cause problems but as a routine matter on any vehicle I would have flushed the entire cooling system out before changing coolant type.
As @chucktobias said, best to have flushed it out fully first, just in case. You could still go ahead and do it, I flushed my old 98 sitting in a garage F-150 out by draining the radiator, filling with distilled water, and driving a bit. Repeat the process until it comes out clear. Then just fill it with the right amount of non diluted Asian coolant like Zerex. That was my lazy way of not pulling the thermostat out and blasting it with a hose like Scotty has shown how to do.
is the residual amount not significant?
it is significant. So is the heater core.
Will the remaining green coolant in the engine block cause problems
it's too late now. I guess you'll find out if you get sludge or not.
