Cooling system flushed 10x still dirty

[MrStabby]

Since i installed a new radiator in the GTR i've been flushing the system with water as i'm changing coolant type. The green colour of the old coolant has gone, but the water comes out slightly dirty and with a very fine powder that settles out of the old coolant. The powder is too fine to feel. Should I persist with more flushes or is there something fundamental wrong?

[KiwiRS4T]

Depends how you have been flushing it. I have just been doing the same with someone else's car - i.e. draining and refilling the system and it is only slowly getting cleaner but a proper flush would require you to remove the thermostat and reverse flush the block with a hose.

[89CAL]

Are you flushing the heater core as well?

[MrStabby]

I think the heater core control is stuffed - i can't get hot air, so no. But yeah i guess I should give that another go.

I have been bringing to car up to temp (according to the coolant sensor) but not running it long enough for oil temp to get to its normal level.

[KiwiRS4T]

2 hours ago, MrStabby said:

I think the heater core control is stuffed - i can't get hot air, so no. But yeah i guess I should give that another go.

I have been bringing to car up to temp (according to the coolant sensor) but not running it long enough for oil temp to get to its normal level.

So long as its hot enough to open the thermostat ...so I take it you are not flushing the block but just draining the radiator?

[MrStabby]

13 hours ago, KiwiRS4T said:

So long as its hot enough to open the thermostat ...so I take it you are not flushing the block but just draining the radiator?

I've been pulling off the bottom rad hose, and opening the bleeder on the top of the motor, and leaving to drain for an hour or so.

Should I pull off the drop radiator hose and run the garden hose through it too?

[KiwiRS4T]

3 hours ago, MrStabby said:

I've been pulling off the bottom rad hose, and opening the bleeder on the top of the motor, and leaving to drain for an hour or so.

Should I pull off the drop radiator hose and run the garden hose through it too?

To get a flow you have to also remove the thermostat so you could probably replace it while you are at it (with another stock one).

[MrStabby]

Ah. I've already replaced the thermostat, and at this stage I CBF taking it off again.Guess i'll keep going for a while more.

[niZmO_Man]

Remove radiator
Remove thermostat
Run water through everything