rusty coolant water

[ger040 2]

despite my best efforts at flushing the coolant system on my g60 i still end up with this 

I have used vw coolant - cant remember the type its the purple one 

am i just not using enough coolant - roughly a 1/3 to water 

Car has had a new genuine radiator. valeo water pump etc - cant be doing these any good

 

[Dox 22]

Have you hosed out the block and rad prior to filling with coolant?

I always use 50/50 personally with all my cars.

[ger040 2]

Yep flushed out every orifice - run until its clear

[Dox 22]

If you drop a magnet into the water does it clear? I’m wondering if that would help collect rust particles? It would need cleaning often at first, less so as time goes on?

Edited July 24, 2022 by Dox

[Dox 22]

You’d have to secure it in the expansion tank as you wouldn’t want it in the coolant pump

[fendervg 29]

I'd go for 50/50 too.

That must be coming from somewhere, or it could be residual pooling of sludge - I'd check the heater matrix and the thermostat. I guess you would need to check every single pipe and hose. Might also be worth putting some actual rad flush/cleaner through it first - the bare metal will develop surface patina in a couple of hours if it's wet. Most important would be that the cooling system is acutally working to spec - what tends to happen is that if you swap out one part of the system with new, this puts additional pressure on the rest and causes a failure somewhere else.

[ger040 2]

Thanks for the replies 

I will flush the system with a rad flush, increase the coolant content and see how it goes

[1xshaunx1 27]

Use demineralised water or give it a good boil before you add it to the coolant. 

[Cressa 44]

As Shaun says, de-ionised water. Cheap enough, although not as cheap as tap water I know. I'm no scientist but there must be a good reason we are told to use this and mine has always been fine.

My daily has a slight coolant leak which I was topping up with tap water and this went mucky like yours. 

Good luck

[fla 9]

 

When i flushed mine out years back i did the following:

Drain the old coolant from the bottom hose

Refill from the top hose

Circulate until the fans come on

Allow to cool and drain.

Keep the drain hole.open and put the hose pipe into the header tank. Fill the system and start the engine. Keep the water going and the engine running. You'll see some steam start yo come from the header. Once the water is clear, close the drain and remove the hose.

Circulate for a short while. Allow to cool, drain and fill with the VW rad flush liquid - its bright orange. Circulate this for about 20 mins.  Allow to cool, drain and flush with fresh water.

Drain again and refill.via the top hose with the correct mix of g12+ and deionised water. Bleed by massaging the hoses.

Good luck!

[fendervg 29]

Good tips there - there is also a drain plug on the bottom left of the "crack" pipe, water pump side - you can get to it from underneath. This is the official way of draining the system as it's technically the lowest point, but depending on how old the pipe is it may be seized or will break when you try and open it.  To be honest if we are at the full lfush stage, I would advise replacing the pipe and the thermostat housing and thermostat if not done already.

I usually fill via the header tank, it will drop quickly when the stat opens and you will need to add more, and work the air out by squeezing the radiator hoses. Some of it will come out via the tank overflow anyway. Then top up, go for a short run at temperature, let it cool and top up again to between min and max marks. Whatever you do don't remove the expansion tank cap when hot as it's pressurised.

[1xshaunx1 27]

When cold it should be on the minimum level marker. As it gets hot and pressurises it should read max on the level marker of the overflow tank. 

[oneohtwo 8]

VW now do the latest coolant ready mixed. Naturally it's an opportunity to charge far more, but it does at least avoid the demineralised/de-ionised/distilled water conundrum, and you can top up as necessary without having to use tap water!