For coolant, is there a difference between idling and driving?

Flushing my coolant system and using a coolant cleaner. Does it make a difference at all if I just idle and rev the engine a bit with my heater core open and bring it to temp - or if I drive it around or does the coolant basically get pumped the same by the water pump?

 

Whether you have the 1GR or the 2TRE, there's only one water pump that's belt driven on the front of the engine.

 

So - basically - letting it idle would be the same as driving it around (I have the 1GR). I don't need to drive the truck around to get more pressure or flow from the coolant to get a better flush?

 

Reving the engine at about 2,000 rpm will bring up the temps faster.
Which will open the thermostat faster.
It also makes the water pump turn faster, which in turn “can” help purge the air better.

The 1GR isn’t very picky.
You can rev or idle, it won’t care.

 

Cooling systems don’t go into full circulation until certain conditions are met.

cooling cleaners are generally not advised.

when people have clogged heater cores they try to save they usually flush it with hose water and *maybe* a cleaner if they’re not trying to replace a clogged old heater core for some reason.

 

The dealer isn’t driving around when they flush your system.

 

Thanks for the info. As for the dealers - I've seen them use a machine that pushes the coolant through and circulates it through the machine. Which I figured is different than my method of just fill and drain a few times (and run the engine for a bit).

 

1) Drain cooling system

2) fill with clean water

3) Start engine, let it get up to operating temperature and run a while.

4) shut off engine

5) repeat step 1-4 until clear and clean water drains out of system.

6) drain water out of truck and fill cooling system with a 50/50 coolant mix.

7) make record in maintenance log

8) repeat steps 1-7 100k miles later

 

And just for info. The heater core is always fully open to full circulation regardless of the temp setting. The air temperature is controlled by a servo that meters the blend of hot and ambient air temps.

 

Thanks!

 

On an aluminum block engine that hasn’t just been utterly abused, there is no real reason to use any sort of cooling system cleaner. That is really more for cast iron blocks that were ran with very old worn out coolant or were refilled with tap water that caused rusting of the block. Just new coolant ought to do the job. As such, you don’t really need the water pump pumping anything around, but to get the air out after refilling you will want a funnel kit and will want to bring the engine up to operating temp. If you just let it idle, it will take forever to get up to temp, and maybe not even get there. You will need to rev it up to get it warm.

 

What do the directions say?

 

If your current coolant doesn't look nasty, I'd skip the flush, but that's just me.
Sometimes we all fall victim to the phrase, "if it ain't broke, fix it till it is".

 

Flushing doesn't do anything

Just drain and fill