disclaimer: i'm not a mechanic, just DIY.
my way of flushing the cooling system.
1. remove thermostat - you need to buy the thermostat gasket + some thermostat sealant in preparation
2. fix back without thermostat
3. add in radiator flush to radiator and start engine, let it run for a while until warm or follow instructions on bottle
4. let engine cool down, remove radiator plug at bottom and let all drain out.
5. fill with water, and repeat cycle maybe 2-3 times to make sure all radiator flush cleared out from system.
6. wait for engine to completely cool down (few hours!). for final 'rinse', remove top radiator hose from engine block side.
7. start engine and fill water FROM top of radiator so that fresh clean water can go through entire system, it will come out from top of engine block where you removed the hose (that's where the water goes back into radiator on top then goes back into engine block via bottom hose.
8. now flush out all coolant, install back thermostat + gasket and fill up with water + coolant.
while doing #7 above, don't hard rev the engine, just idle should do but monitor the temp. also make sure engine truly cool down, because you don't want cool water getting to hot hot engine, not a good scenario to be in.
very very elaborate, i don't even know worth the time and effort sometimes

only do it very very rarely

p/s: oh to add, for step #7, please COVER the distributor with plastic to protect from water splash. otherwise after done this, your car won't be able to start. learnt this the HARD way

QUOTE(low yat 82 @ Oct 16 2011, 09:36 AM)
try 13" steel rim bro. darn fuel sayin la...lol...
ya. got it run for quite sometime wit radiator cap opendedÂ
lol... i guess some water still inside engine coz when flushin i swtich off engine makin d pump not workin. so mayb can say d concentration of coolant is 1.5L: 3.5LÂ

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lol..burping engine.. like after eat heavy heavy.. i guess all air pocket come out d gua... let it run some time after pour in coolant n water...hopefully no air pocket liao..Â

This post has been edited by poolcarpet: Oct 16 2011, 10:57 AM