Alternative coolant change proposal for gen5 rav4 a25a-fks engine

[windeye]

I have read thru the service manual for coolant change. The procedure by toyota involves racing engine to above 3000 rpm to place system in fill mode, and repeat 3 times.

With the understanding of how the system works, I am proposing the following alternative, main reason is to avoid racing engine to 3000 rpm at no load condition:

Disconnect the electric connectors on the two coolant bypass valves. This ensures the coolant go thru the heater core and atf cooler. Then use a scantool to raise water pump speed, to say 2000 to 3000 rpm, add repeat 3 times ( let pump rest for a minute or two in between.

What do you think?

Scan tool does not seem to have a function to enable fill mode, but it does have the ability to command the water pump.

 

[iCurious]

On the 2.5L non-hybrid engine, I just use the lisle funnel and prop the gas pedal with a stick, raising the rpms to 2500 and let the fan cycle 3-4 times and I am done. Don't over think it.

 

[windeye]

Wow. Thanks for sharing your experience. Might as well do that.

 

[windeye]

Further reading on service manual indicated that toyotas GTS has ability to turn on and off those coolant valves, so I just need to check if my Launch can do that as well. Car is with one of my kids in west coast, and I am on east coast.

 

[JHZR2]

What’s the matter with raising the speed if it’s an FSM mandated approach?

Seems stupid, versus having a self bleeding system or a simple procedure that is set electronically.

But toyotas are reliable and so one would hope the mandated approach is of no concern.