Hi All,

Bit of a puzzle this one. Certainly something I've never seen before.

The rad on my car has a flat type cap and the system has an expansion tank that has an 11psi cap.
This cap is the highest part in the cooling system. There's an air gap of 50 or so mm under the cap.
Coolant is water and Commer antifreeze. (See Pic)


When I remove the cap to check the water level periodically there's a jelly like crystal substance around
the rubber seal washer of the cap. I wipe out the ally weld on cap holder on the ally expansion tank,
wipe the cap itself, top up if necessary and replace. Next time it's back just the same.

Not the easiest thing to show in a photo.
Anyone shed any light on this ?

Paul G



Description


[Edited on 28/4/16 by 907]

That's what happens when you mix two different types of coolant, and it's a really bad thing. From 'tinternet;

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the two chemicals of Ethylene Glycol (green) and Dexcool (orange) are not compatible. When mixed together they form a gel-like substance that stops coolant flow and consequently the engine overheats.

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Looks like the result of mixing glycol and OAT anti-freezes. Try a cooling system flush in the system and a good rinse out then refill with fresh OAT. I'd recommend Forte flush and could bring bring you a can to Stoneleigh.

OAT. coolant is glycol based the difference is the inhibitors.
The BASF coolants used by BMW and VW are infamous for this type of issue if mixed with other coolants.
Acid flush with citric acid then water wash and refill with standard OAT

To the best of my knowledge it's not a mix of the two types of antifreeze.



However, you have all got me thinking.

I have come across the information from several different sources that OAT and yellow metals do not mix.
That cap in the pic is brass, as is my radiator.

Looks like I need ethylene glycol.
I will investigate further tomorrow.


Thanks for the replies
Paul G

If you need something that's good for yellow metal, solder and other things the modern stuff doesn't like much then John Deere 'cool-guard' is about as good as they get (and your bound to have a dealer fairly near by)

Don't take everything you read on the internet as gospel. The goop problem first came to light on BMW Minis! the BASF coolant used is bio-degradable mix it with other coolants and it bio-degrades,
The yellow metal thing is a exaggeration modern engines still have yellow metal coolant sensor, I have yet to remove one showing any signs of corrosion.
You will also read on the web that it attacks nylon 66 this is a total myth-- nylon 66 used on some plastic water pump impellers about 15 to 20 years back was problematic because it wasn't suitable for the temeratures involved.

OK. Ive searched through the old cans in the garage and found a 5L can of Halfords ready mix (blue) dated 2008. Nearly empty.

It says "silicate free organic acid formula" but also says "contains ethylene glycol". That confuses me.


As the last 3 cars I have owned have been VAG (11 years) I must of had this in the Lotus.

In Nov 2014 I was preparing for IVA and playing with fan switches and thermostats, and when I got this sorted
I drained what remained of the coolant and put the G30 (red) in. If the last drop didn't drain then there could be
a mixture.

Looking for a make that states categorically what it is I've come up with Comma Super Coldmaster that says
it's Mono Ethylene Glycol and is specifically for old engines with mixed metals.


(Googled cool guard and got sports bras . John Deere cool guard says its propylene glycol ? Thanks anyway)

I'm going to drain the G30 and fill with water and run the car to get it hot, drain & repeat. Then fill with Coldmaster.



I didn't realise that antifreeze was so complicated.
Thanks,
Paul G


[Edited on 29/4/16 by 907]

Having driven and serviced VAG diesels for some time I do know that the pink VAG coolant liquid quite clearly states "do not mix with other coolants". I'd guess down to this issue. With that I've always used VAG spec pink coolant and not had any issues with it.

I did a head gasket on a Polo a few years ago that looked as if the cooling system had been filled with thick strawberry yogurt , the only explanation was a mix of different types of antifreeze?

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Originally posted by rusty nuts
I did a head gasket on a Polo a few years ago that looked as if the cooling system had been filled with thick strawberry yogurt , the only explanation was a mix of different types of antifreeze?

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Did it do the job?

quote:

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Originally posted by rusty nuts
Did it do the job?

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