Flush question

[PW01]

The other day, my Mom gave me a credit card and asked me to run here car to VIOC to have the radiator flushed. I watched the guy do the job, and told him I thought the car should be running while he flushed it - he said I was wrong. It seems to me that you would want the car running to insure that the thermostat was open, and to be sure that the heater core was adequately flushed. Who was right?

 

[mazduh30]

I would think you would need a block drain if car wasn't running. In my opinion, a running vehicle would ensure most of the old coolant was removed.

 

[flatlandtacoma]

All he did was flush & refill the radiator with the thermostat closed.

 

[ConfederateTyrant]

You were right, and unfortunately your mom got charged for bulls*** work. Unless the actual service is called a radiator flush, instead of a coolant flush.

 

[Donald]

I would tend to think you want the thermostat open to do the best flush (along with the heater control on).

However even with the thermostat open as the machine pushes new (cold) AF through the system, won't the thermostat begin to close? I know at the same time the engine will be heating up the new AF, but can it heat it up fast enough to keep the thermostat open.

 

[BennyL]

you have to run the engine until the gauge shows operating temp. that way you know it's circulating properly for the flush.

 

[doitmyself]

If you tapped into the correct heater hose, with the T-stat closed, wouldn't you back flush all the old fluid through the engine, into the bottom radiator hose and then out the radiator cap?

Isn't that what a back flush procedure is all about? Enlighten me. There would only be a tiny amount of fluid left in the top radiator hose if the T-stat didn't open, correct??