I started my car for the first time today, ran great, but at the end of the day I checked the radiator make sure it was full, which it is, but the very top of the coolant is grey. It will swish to the side and green is right under. What do you guys think? I'm going to flush my coolant system tomorrow. Btw, this is an old radiator that I have never used before...

 

No way to answer this. You used an old radiator so it might be contaminants from it sitting or junk blown into it from the death of an engine from its previous life in a different car.

It does look interesting though. How does it taste?
:p

 

Maybe the remnants of one of those stop leak things.

 

I believe traditional green coolant separates (for lack of a better term) over time. It sort of gunks up radiators. Why not get a new-er-ish radiator?

EDIT:

The picture is the best thing I could find. I saw a thread on here about this not too long ago (<1 yr). Someone was talking about blue coolant or some other radiator system and this came up. I couldn't find it (didn't search) but I found this on Google. I will search and add the thread if I can find it.

 

Ew. But how much time would that be? And why is this in FI?

 

I cannot answer either of them. I saw a test done to compare traditional coolant with Honda Type 2 (Blue coolant). I remember the picture vividly. However, I cannot find it or even remember the name of the thread.

 

im thinking because some people dont drive there car daily and may leave it parked for some time.

 

.

Could be a big concern to those running water cooled turbos .... That stuff might get gunky with the turbo heat

 

How about a concern for anyone running coolant? Which would be everyone, so nothing special there. Just didn't see any indication in the OP of a boosted vehicle. Also hoping the OP isn't just sitting there taking pictures and staring at it and has since flushed the system (which he claims he will do) and maybe gotten a new radiator.

 

I'd definitely get a new radiator and flush out the block before using it. That's stupid nasty. I can only imagine what has settled if that is on top.

EDIT:
I'd trust 4drEF on this one. Definitely more experienced than I am.
His post below sparked this edit.

 

What odd is that silicate fallout usually settles to the bottom.
He's able to poke around at the surface and see green fluid underneath.

The pic makes it appear to be whitish looking... like old chewing gum. I have heard of phosphate based coolants producing oxidized aluminum salts. If that was in the radiator while it sat unused maybe it created a film that came off when the OP started using the radiator.

I think he can probably get away with just a flush.

 

My initial thought is that it was the oxide from aluminum that once cycled it separated from the metal and is now suspended in the coolant.

 

Its just moisture guys, flush it good and run it