coolant question

[jamesandtheopenroad]

Over the weekend, when parked facing down hill on starting her up, the coolant warning light continued flashing. This stopped when level but leads me to believe that the coolant level is probably I bit low.

Now, I've had her just over a year and as far as I know the coolant wasn't changed for a little while prior to that. I've read posts on here and the Wiki, including kevtherev's perennial coolant change, but am still a little confused, so apologies. But my questions are these;

Can I just top up to the correct dilution with G12+ coolant (or equivalent) straight into the header tank? (As I understand it, G12+ will be compatible with whatever type of coolant is already in there).

Or is it better to empty the system and do a complete fill (7.5l coolant to 7.5l water), bearing in mind - I ain't never done nuffin like dis? And if so, how do you dispose of the old coolant?

Thanks.

[Red Westie]

The coolants additives break down over time so it stops protecting the engines internals from corrosion the way it should.
Old style blue/green coolants only last two years before they need changing, new OAT (organic acid technology) based coolant lasts up to 5 years but as they were not around in the 80's people continue to apply the old two year change schedules to the long life OAT antifreezes but there is really no need.
OAT antifreezes are typically yellow/orange/pink/purple and their chemistry is much more stable so lasts much longer. On newer VW's where G12++ is used the service schedule suggests that they are 'filled for life' not that I would recommend this but it just shows how much confidence VW have with this latest product.
50/50 mix on wasserboxer (watercooled flat four VW's) 40/60 is fine on others (Diesels/SA 2.5)

Take off your engine bay cover (in the van) the main tank (the one you can not see from the number plate flap) should be full to the brim, the top up (overflow tank) you can see behind the number palte, fill to the indicated line.

If you do 'change' the antifreeze, make sure you thoroughly flush out the system to ensure any old 'acidic' antifreeze has gone, before refilling. I would pour in 'the neat' antifreeze, all 8 litres, before adding water. I say this because you can never get more than 50/60% to drain.

Old antifreeze should be collected and taken to the council's oil disposal point.


Martin

[AdrianC]

Or is it better to empty the system and do a complete fill (7.5l coolant to 7.5l water), bearing in mind - I ain't never done nuffin like dis?

If you don't know how old it is, replace it - and have a very good look over all the hoses & pipes, too - there's several steel ones in there which rust badly. There's been a thread in the last couple of days about it...

[jamesandtheopenroad]

Thanks peeps.

I've had a look in the header tank and it's pretty low so going to do a drain, flush, fill and bleed. Can't really tell exactly what colour the current coolant is, but it's definately not pink/purple/orange so I guess is blue/green G11.

Been reading more on here and the wiki - plus my trusty Haynes manual (clear as mud some of the instructions in that ) - so as far as i understand it to drain it i need to;
- place 20l container underneath engine
- have heater on HOT
- remove caps on header and expansion tanks
- remove lowest hose on engine
- remove header and expansion tank caps
- let the bugger drain

To flush:
- disconnect hoses at the thermostat to and from the radiator
- attach garden hose and flush out rad, repeat the other way
- disconnect hose at coolant pump
- attach garden hose to coolant pump connection and fluch out water jackets
- disconnect both hoses to the heater
- attach garden hose and flush the heater both ways.

(will this flush all the little distribution pipes between thermostat/tanks etc and the manifold?) And obviously, I'll flush the rad, water jackets and heater both ways and so the water runs as clear as dammit, but incase that hasn't got rid of the last collant 100%, G12+ is compatible with G11, right?


To fill;
- reattach pipes
- open up bleed valve on thermostat
- pour in 8l of coolant into header tank coolant or until no more can be put in
- follow Mr Baxter's bleeding tips
- add water accordingly
- repeat etc

Is that all correct? Sorry of it's overkill, I just want to do it right.

Also, it says to use clean water to mix with coolant - I presume that standard water from a tap is sufficient (I read on one post that you need to use distilled water - is that true?).

Thanks!

[Red Westie]

Personally I have never seen any bad issues from using tap water but what people are saying is distilled water is pure and uncontaminated so is prefered (pain in the rear if you ask me and unecessary unless you have a particularly bad water supply (lots of limescale etc)

Your desciption sounds fine BTW.
Just don't allow the engine to overheat whilst bleeding.
Martin

[AdrianC]

Personally I have never seen any bad issues from using tap water

Back in the late '80s, Citroen had a lot of problems with the blocks on turbodiesel CXs going porous - but they seemed to be geographically clustered. It turned out that they were cast from poorly recycled scrap, and tapwater used as coolant corroded the impurities out, but only in some areas - depending on tap water quality. Cars which had been maintained in "good" areas or with distilled water were fine. Except, of course, they then didn't get a rebuilt and fixed engine under warranty...

So whilst it can "cause" problems, they're usually pre-existing ones which are merely highlighted more quickly. I've never really worried about it - and I'm in a very hard water area. Never had problems as a result.

[Ian Hulley]

they were cast from poorly recycled scrap

That sums up Citroen quite nicely don't you think.

[jamesandtheopenroad]

Thanks again.

Last question, found this cooling system diagram on the wiki which differs from my Haynes. The Haynes says it's diagram is for an early T25, so is this for a late?

https://club8090.co.uk/wiki/Pe ... em_diagram" onclick="window.open(this.href);return false;

Ta muchly

[AdrianC]

so is this for a late?

Aye, that looks _very_ familiar from our '88 van...

[jamesandtheopenroad]

Cool, thanks.

The only difference I can between this and mine is that instead of a hose between the oil cooler and the thermostat, the hose actually goes to the manifold, which makes me think that this is for a 2.1 instead of a 1.9 (but everything else should be the same I guess - well, apart from the manual transmission).

[AdrianC]

which makes me think that this is for a 2.1

...which ours is.

[jamesandtheopenroad]

starting to get my head around this engine malarky ...