Draining the radiator gives 3L

[Member 1]

I drained the radiator and that gave me only 3L. The coolant is really dirty (damn dealer never bothered to check), I removed the overflow and that had 1L (the reading level was too high).
I thought I should get 4L or probably more when I drain the radiator?
I tried to fill the system with demineralised water and ran the engine until it reached operating temperature then drain it. It's still not clean.
Two questions:
1. Eventually, how can I add 6L of the coolant concentrate? I will not get a 50/50. I will get around 70/30
2. I tried to avoid adding tap water into the radiator. That is why I used demineralised water in the whole system. The problem is; coolant is really dirty. Should I flush the radiator with the garden hose? I live in an apartment and this will cause a mess in the shared lock up garage.

 

[c2105026]

According to the workshop manual, apparently you need to take out the knock sensors to get all the coolant out of the block. Now....a dealer mechanic told me once that noone does that, its actually really difficult to do.

So yes, flush out radiator with garden hose, do the same with the block. I have seen you tube clips of Ecotec radiator hoses solidified with sludge. Its the special coolant tablets GMH specifies, left too long it turns to mud. The level of concentrate isn't a significant issue (I use the green coolant) - if you have 4L out, mix up 2.5L water/2.5L concentrate for 50/50 mix (have 5 litres - litre left over as spare, as your level may have been running low) and fill up the radiator when cold. Drive (to purge the system of air) and fill up the radiator again after it cools down. Keep repeating until the radiator basically full when you take the cap off when cold.

(I appreciate this may not be the 100% correct way of doing it but this is the way I did my last coolant change - have had zero issues with coolant level and cooling performance )

 

[Member 1]

Thanks c for the reply

I think the manual says the system has 12L. If I take 4L out that means that I have 8L of the water (probably mixed with very little of old coolant). The 50/50 means the system should have 6L of concentrate and 6L of the water. Why should I mix any more water to the concentrate?
If I take 4L out, that means, at least I should add 4L of concentrate and that will make it close to 70% water to 30% concentrate.
Are you suggesting that I should add 4L of concentrate (to get 70%water 30% coolant) and not worry about it? and then add the concentrate when the car cools down (after driving)?
Is it normal for the radiator to drain only 3L?

 

[Member 1]

So yes, flush out radiator with garden hose, do the same with the block

Do you mean reverse flush the radiator (add the water hose to the bottom snout and drain the upper radiator snout? or just add the water hose to the top radiator snout and drain from the bottom?
As far as using the water hose to flush the engine block, I honestly do not know how to flush engine block with the tap water hose. I could not figure it out from here;
https://forums.justcommodores.com.au/threads/how-to-flush-a-v6-cooling-system.28762/
Also, since I can only drain 4L out the system (and cannot drain the engine block from the knock sensor as you rightfully said), I will end up with 8L of tap water in the system (except the radiator and the overflow as both will be empty), ie mostly in the engine block (and a little bit in the heater core).

 

[c2105026]

Every car I have ever had drains out less than the advertised capacity. Auto transmissions are the same. Mix up a bit more than what came out, put new mixture back in. You won't be doing a complete change, granted, but at least the coolant is much fresher. I don't think you will be flushing an extra 8 L out of the block and core, quite a lot will still be trapped. In fact, what is below the level of wherever the bottom hose connects to on the block will remain, unless you take out knock sensors etc.

To flush the block, stick the nozzle of hose in at the top once you have taken off the top radiator hose, turn on full bore for maybe 2-3 minutes, or until water coming out is clear. Ensure the bottom hose is pointed towards a bucket, it can get messy.

Don't get too hung up about actual coolant concentration. even if its just 30 coolant 70 water mix you'll be fine. Proportion relates mainly to the antifreeze temperature; if like most Australians you live on the coast you'll never get the freezing temps that warrant high coolant concentration.

 

[greenacc]

You just jam the garden hose in every hole you can get access to and run plenty of water through it. Doesn't matter which direction.
Removing the radiator hoses from engine can help too.

 

[Member 1]

Every car I have ever had drains out less than the advertised capacity.

Thanks again

I interpret what you say as getting only 3L out is not unusual.

To flush the block, stick the nozzle of hose in at the top once you have taken off the top radiator hose,

Stick the nozzle of hose in at the top; do you mean remove the clamp connecting the upper radiator hose to the thermostat housing?
Should I remove the thermostat beforehand?

Ensure the bottom hose is pointed towards a bucket, it can get messy.

the bottom hose connects the radiator with the engine block. Which clamp should I remove? the one connected to the engine block or the radiator?

 

[Member 1]

Thanks again. I just flushed the radiator with the water hose. I reversed flushed it too until it ran clear.

 

[c2105026]

It is common to maybe even only get half the advertised capacity out of a cooling system.

take off top radiator hose completely. Gives you space. Stick garden hose into where top hose joins the motor.

for the bottom hose, take the clamp off at the radiator, and ensure its over a bucket (or other very large container)

 

[lout]

flush the radiator and block, refill with clean water, turn heater to hot run engine until hot,
then drain and fill with concentrate
with water that remains in block works out close to 50/50 mix