Silicate dropout

[Tones]

The more I read and think about it the more I am convinced that my 05 Volvo has had silicate dropout. There are white soft deposits that can be seen in the coolant reservoir. I intend to drain the coolant and run a couple fills of water through it. Anyone think I should do more than that? Any products you can recommend to clean it? TIA.

 

[Vilan]

For what it's worth, when I changed the (conventional green) coolant on my 94 Metro last year, I had a real thick layer of goo at the bottom of my overflow tank. I assume there's some in the radiator too. But... the radiator still works as well as when I got it. So you may not have much to worry about.

 

[Big Jim]

I don't think that your 05 Volvo came from the factory with a coolant that has much if any silicate.

 

[Tones]

I wondered that too Jim, so I bought the Volvo coolant (part no. 9434699-6). It lists silicates in the ingredients. In fact, I was going to look through the posts here to see what it is compatible with. Here are the ingredients:
Ethylene Glycol(107-21-1), Diethylene Glycol(111-46-6), Sebacic acid(111-20-6), Sodium hydroxide(1310-73-2),2-Ethylhexanoic Acid(149-57-5), Corrosion inhibitors, Defoamer, Silicates, Dyes

It states "Phosphate-free" on the front. Looks like an OAT formula?

 

[Big Jim]

I would guess that it is a low silicate formula similar to G05.

 

[Tones]

Before I bought it, I would have thought that too. It is the presence of the 2EHA that throws me.

Edit: further searching shows that this is the G-48. This chart is extremely helpful.

 

[Ray H]

G-48's a near G-05 clone. 2-EH is the organic acid salt component in DEX-COOL, too. It can be bound to either sodium or potassium when used in antifreeze. Zerex specifically lists G-05 as compatible with Volvo cooling systems. The silicate content of G-48 is minimal just as is G-05's. Do repeated distilled water flushes with full engine warm-ups until visible evidence of previous coolant marker dye in the effluent is elliminated. What remains in the cooling system will be essentially distilled water - and about half the system capacity assuming you don't open the block drain plug. Refill with G-05 concentrate unless you already bought Volvo's high-priced G-48 syrup.

 

[wander2039]

On my wife's 04 Escape with 40k I noticed the same deposits. I did several flushes and it didn't seem to help any. I'm sure it was the factory fill of G05. Eventually i'll install a wix coolant filter on it just to see what it catches. Maybe the new formula's of antifreeze isn't as good as they should be?

 

[Big Jim]

I noticed a little bit of that white powdery trace on cars using G05. It is common. I don't know what it is, but it seems harmless.