Silicate fallout with conventional green, ( pics )

[FCD]

I had the radiator re-cored on my Capri about 3 years ago due to leaking.
All the car has ever seen is conventional green coolant.
For the past 4 or 5 years i've been using a cheap parts store brand conventional green IAT coolant, ( 30% premix )

I noticed back in august when i drained the radiator to replace a hose that the inside of the radiator looked like this :

Nothing strange to see when radiator is full
radiator by Argentum Enim in Sempiternum, en Flickr

However when the radiator is empty :
Silicate gelling by Argentum Enim in Sempiternum, en Flickr

Silicate gelling by Argentum Enim in Sempiternum, en Flickr

I went on a road trip in July, the weather was predictably very hot, on the way back home it was +40C ( 100F ) all the way home which was over 300 miles.
The car got fairly hot once, didn't quite overheat but the temp gauge got nearly up to the red zone, i stopped and let it sit for an hour at a gas station, squeezed some coolant out the filler cap thinking maybe it had too much coolant in it, i went on my way and got home without a problem.

I think this dropout might have something to do with it, i changed the thermostat after the road trip and the coolant ( using a different brand of conventional green )
I've looked into it though and i think i'm going to switch to VW G11 for it, as these don't suffer from the problems of a poorly stabilized conventional green..

 

[KrisZ]

Looks like either the coolant in there was kept for too long or it reacted with something. Is there a possibility of another coolant type being used?

 

[FCD]

I have exclusively used the exact same coolant for the past 4 years on it, the coolant was no more than a year old, since i've been replacing several old hoses in the cooling system due to age.

 

[Onetor]

What about the H2O used? Distilled?

 

[StevieC]

Originally Posted by Onetor
What about the H2O used? Distilled?


+1

I used Green conventional coolant in my Hyundai Santa Fe as that is what it came with and it never did this in all the miles I drove it. I did change it every 2 years regardless of mileage though and we use a 60/40 mix here because of the winters.

 

[dogememe]

Why not switch to Zerex G-05/Motorcraft Gold?

 

[KrisZ]

Could be the cheap brand of coolant, who knows? Looks like a good flush, or several are needed.
I agree with G-05 suggestion.

 

[FCD]

I didn't add any water, i have until now used 30% premix in it.

 

[FCD]

Originally Posted by dogememe
Why not switch to Zerex G-05/Motorcraft Gold?

Because neither exists here in Spain

The Motorcraft coolant is some type of pink extended life OAT and really expensive, no Motorcraft gold here.

 

[StevieC]

Whatever you decide to use a flush/fill is definitely in order for that cooling system if not more than one.

 

[doitmyself]

There's a few good articles if you Google "coolant silicate dropout".

Most say similar to this: "These silicates under certain circumstances (coolant with a depleted additive package (worn out coolant), hard water (water mixed with coolant), high coolant temperature, over concentration of coolant (not enough water)) have a tendency towards "polymerization", which can cause silicate "dropout" or "precipitation" which can lead to gelation of the silicates in the coolant." Add to that possible poor quality new coolant?


How does a person manage a coolant system only using prediluted product that the OP uses? If you do a complete flush with cleaner/plain water, up to half the total capacity can remain in the engine block. It's impossible for the OP to then only add his 30% prediluted coolant and achieve the desired 50/50 mix.

 

[bullwinkle]

I would put a blank coolant filter on it, between the heater hoses-you'll be amazed at how much junk it'll catch!

 

[nthach]

I thought old-school phosphated and silicated green wasn't a thing in Europe?

I know you were planning to switch over to G-40(VW G12) or G-48, I would use the Mercedes citric acid fluid to get as much of the silicate drop out out as possible.

 

[FCD]

Originally Posted by nthach
I thought old-school phosphated and silicated green wasn't a thing in Europe?

I know you were planning to switch over to G-40(VW G12) or G-48, I would use the Mercedes citric acid fluid to get as much of the silicate drop out out as possible.

Conventional green very much does exist in Europe, it's blue in the UK and also widely available.

Confusingly i've also seen G12 OAT dyed green here and regular "green" phosphate / silicate IAT dyed pink

We have some all makes all models coolants too that are usually yellow.

I'm planning to switch the Capri to blue G11 after a good flush of the whole system.
I'm going to put Eurolub D-40 Super ( G12++ , Silicated OAT ) in the Escort next week after a good flush ( running G12+ right now )

 

[FCD]

Originally Posted by doitmyself
There's a few good articles if you Google "coolant silicate dropout".

Most say similar to this: "These silicates under certain circumstances (coolant with a depleted additive package (worn out coolant), hard water (water mixed with coolant), high coolant temperature, over concentration of coolant (not enough water)) have a tendency towards "polymerization", which can cause silicate "dropout" or "precipitation" which can lead to gelation of the silicates in the coolant." Add to that possible poor quality new coolant?


How does a person manage a coolant system only using prediluted product that the OP uses? If you do a complete flush with cleaner/plain water, up to half the total capacity can remain in the engine block. It's impossible for the OP to then only add his 30% prediluted coolant and achieve the desired 50/50 mix.

I'm probably going to stay with a 30% or maybe 40% coolant mix, not 50/50.
If i make two jugs of 50/50 i only get enough to fill the cooling system, i want to have some left over to be able to top up just in case.

 

[DoubleWasp]

I'd put a coolant filter on that thing for sure. Not everything is going to come out in the flush.

 

[FCD]

Not sure where i'd put a coolant filter.

 

[DoubleWasp]

Any place where it can tee into the heater hose lines. Or is the engine bay just that tight?

 

[Ducked]

Originally Posted by DoubleWasp
Any place where it can tee into the heater hose lines. Or is the engine bay just that tight?


Don't remember either of the OP's cars as being especially tight for space.

I think that's mostly a modern inconvenience.

 

[FCD]

The hoses going to the heater core are very accessible now that i think about it....

Colector by Argentum Enim in Sempiternum, en Flickr

Also, here's a pic i took back in July when i was just changing the thermostat housing gasket and while i was at it put new thermostat in it, i took some pics inside :

IMG_20180628_191402 by Argentum Enim in Sempiternum, en Flickr

Looks pretty rusty and corroded doesn't it? the inlet manifold is aluminium so it shouldn't really look like that should it??
Again as i say this car has had nothing but cheap parts store brand conventional green IAT coolant for years.