Flushing the cooling system

[Dayvo]

Hi all
The time has come to flush out the cooling system and renew the coolant and inhibitor . What I want to know is do you have to remove the knock sensors from the block ( V6 ecotech ) to completely drain it or can you just back flush the motor till the water runs clear and refill it then bleed it via the thermostat ?
Thanks

[Shounak]

To get the water out of the block, you have to remove the knock sensors.. You can flush the water til it flows clear, but there'll still be a shit load of water in the block..

So it's completely upto you really.. The last flush I did, I didn't remove the sensors..

But on hindsight I probably should have.. I mean you only flush and drain it twice a year..

[IBLOWN]

why would you remove the knock sensors?

[Shounak]

To get the water out of the block..

[ScottB_33]

I've never found a need to remove the excess coolant from the block as I find it can create more problems as in broken sensors or damaged wiring for not that much gain. If your using a good quality coolant such as Valvoline GO5 that we use in my workshop it is compatible with all coolants and inhibitors and if you keep the system clean and scale free and you change the system at the correct intervals, then I find this step of draining the block unecessary work!!! By the way I always check customers cars with a glycol tester to test the efficiency of the coolant before I change it!!!

[IBLOWN]

if you flush the coolant in a way that the flush circulates the whole engine and radiator, and start the car while the its flushing (only for 20 secs or so) why remove the sensor?

[Dayvo]

the Haynes commodore manual says to remove the knock sensors when draining cooling system and just wanted to know if it was really nececary

[VT97]

im going to flush the radaitor on my vt soon, its hasnt been done for a while and i want to flush it a few times (..its really full of crap!!), can tap water be used to fill the radiator, then flush it straight away like after a few minutes drive? after the engine is cool enuf that is, i know heating and cooling the engine at rapid rate can stuff it up ....so just wondering if this is a good idea or not?

[Bgrade]

Everywhere iv'e read says to use distilled water in your radiator?

Iv'e got all the gear to flush my radiator but im too scared to take out the knock sensors and there is too much conflicting info on wether or not to add those pellets to the radiator. I've got the gregorys manual but im a little sceptical. So I'll ask the questions wev'e all been wondering for ages.

1: Do you use distilled water?
2: Do you add the pellets?
3: Do you really need to take the knock sensors out?


thanks:my:

[IBLOWN]

its really not necessary to remove the knock sensor. if the old coolant got in, it has to come out.