So.... whats going on here then?

[Steve_PPP]

Having done a few bits on the car lately myself, I've been paying close attention to it - far more than my usual "if it works, don't fix it" approach.

In the last month i've replaced radiator, top/bottom hose, oil modine hardpipe, plus modine removed and O ring replaced. Old coolant was the pinky orange long life stuff.

Now its all back together and running using Motul expert coolant (clear blue colour). New radiator has a rad cap but it's been plumbed into the expansion bottle correctly.

I've got about 7.5 litres of coolant in, pretty sure there's no airlocks. Hot air through vents inside, both hoses get hot, fans kick in as required etc. Car drives fine, doesn't overheat.

Gave it some stick last week after it had been put back together and all seemed fine. Went to take it for a drive last night and checked coolant before starting the car - level in header tank was slightly down so topped up. (might have been that it settled and purged some air after first drive week before?).

However, before topping it up, i noticed this on top of my nice new coolant...difficult to get pics on a phone but you get the idea.





At the time of taking these pics, the car had stood untouched for just over a week. As soon as it was started, the contaminants on the surface mixed/disappeared.

Now... I used some degreaser to clean up the oil modine (it was filthy after a slow oil leak for a year) and some could have got inside (although only a tiny amount I expect through the open hose ends). I also fitted the new rad without flushing it through first - didn't even think of it at the time. Could it be a remnant of grease from manufacturing?

Can't see any major signs of coolant leak although the header & rad caps were slightly damp around the sticker. Don't know if its pressurising too much? Guess it can't hurt to try a new header tank cap as i've read of a lot of problems if these fail.

Please don't say its duff head gaskets

If I hadn't started doing bits on the car myself I'd never have even checked and i'd be sitting here quite happy not knowing

[scotty]

Looks like tiny snow flakes lol not seen that before mine didnt do that after replacing rad , oem bottom hose and new header tank cap very interesting .

[Steve_PPP]

Its like little crystals on the surface.... could it be caused from a little water mixing with the motul coolant?? its meant to be used neat, but I flushed engine through with water after dumping the old pink stuff out. Could have been a bit of water left in there...

[BIG"E"]

Head gasket ????







































I do hope not

[Steve_PPP]

Originally Posted by BIG"E"

I do hope not

Me too mate. Probably not worth spending the money on a 94,000 mile WRX engine that's seen its fair share of abuse.

[NL03Scooby]

Did you clean all the mating surfaces you attached your new plumbing too? I wonder if it dragged through some dislodged crud from where your new pipes were put on?

[SlimeyLimey]

Ive done the same job as you mate on my wrx bug, i washed out my new rad into a bucket to see if anything came out but the water was crystal clear with no signs of grease or oil. I did get a few chunks of crud but found that they came from the header tank where bits has got stuck to the inner walls over time and loosened when i changed everything.

...im no mechanic but arent these suppose to have the red/pink coolant? Thats what i was told anyway and was told not to use the blue stuff. As i said though im no mechanic by any means haha

[urabusMY94]

When I replaced my radiator, I also needed to top up the header tank after initial drives.

Let it cool down, see if it's still there and if so, get a sample out to have a better look.

If you don't have a syringe, then a cooking baster will do just as well....

Ideally, get as much of it out as possible so remaining coolant is clean, top it up, and check if more appears after your next drive.

If it disappeared when coolant got hot, then suggests some form of surfactant/detergent which as you've already speculated has a number of potential sources.

You can confirm this by heating up your sample BTW. If it doesn't dissolve, then could use a magnet to check if it's metallic?

Good luck!

[SpecB]

Probably just gunk from the system, mine looked like that after a new engine, water pump, modine etc.

[Banstead Stig]

Originally Posted by Steve_PPP

Me too mate. Probably not worth spending the money on a 94,000 mile WRX engine that's seen its fair share of abuse.

This is the trouble with these dodgy 2.0 engines you see...

Seems likely this is just something picked up from having it all apart or, as you say, a bit of grease from manufacturing.

[Steve_PPP]

Originally Posted by NL03Scooby

Did you clean all the mating surfaces you attached your new plumbing too? I wonder if it dragged through some dislodged crud from where your new pipes were put on?

Yep, cleaned up everything reasonably well.

Originally Posted by SlimeyLimey

...im no mechanic but arent these suppose to have the red/pink coolant? Thats what i was told anyway and was told not to use the blue stuff. As i said though im no mechanic by any means haha

Not sure, I was recommended the blue Motul coolant from Alyn @ AS Performance. This stuff:
https://www.motul.com/za/en/products...%5Brange%5D=25

Not sure that you can rely on the colour 100% as its just a dye at the end of the day?

Originally Posted by urabusMY94

When I replaced my radiator, I also needed to top up the header tank after initial drives.

Let it cool down, see if it's still there and if so, get a sample out to have a better look.

If you don't have a syringe, then a cooking baster will do just as well....

Ideally, get as much of it out as possible so remaining coolant is clean, top it up, and check if more appears after your next drive.

If it disappeared when coolant got hot, then suggests some form of surfactant/detergent which as you've already speculated has a number of potential sources.

You can confirm this by heating up your sample BTW. If it doesn't dissolve, then could use a magnet to check if it's metallic?

Good luck!

Some good ideas there... I was expected to top up the header tank after initial drives but wasn't expecting to see the funny stuff floating on the top

It wasn't properly cooled down last night to check and been at work all day so will pop out to the garage this evening and see if its reappeared. If so, i'll try and get some out for closer inspection....

Originally Posted by BlueBugEye

Probably just gunk from the system, mine looked like that after a new engine, water pump, modine etc.

Cool, thanks mate
Like i said, i'm (hopefully) worrying about nothing but as I did the work on the car i'm paying more attention to it than normal!

[Steve_PPP]

Originally Posted by Banstead Stig

This is the trouble with these dodgy 2.0 engines you see...

Seems likely this is just something picked up from having it all apart or, as you say, a bit of grease from manufacturing.

Haha! Good response mate

Hopefully its nothing to worry about....

[alfa male]

Originally Posted by Steve_PPP

Not sure that you can rely on the colour 100% as its just a dye at the end of the day?

I was always under the impression that different colours mixed form a Gel due to a reaction? Maybe the crystals are part of this process with what small amount of old coolant/contaminant may be left in the system after the flush?

An option?I don't know? Just thinking out loud.

hope all is going to be well mate

[Scott.T]

Just syringe it out as said above.
I wonder why they say use it neat !!!!
Could it be to increase their profit margin ?

Coolant is coolant IMHO. As long as it contains antifreeze it's good enough.

[Red Baron]

Different coolants for the different materials used in cooling systems, copper, steel, aluminium, rubber, silicone, I know VW are very specific about the orange G12 coolant you should use in their cars. Saying that my Scoob has green in it, found that out when I bought some red to top up after doing the top hose. Based on the history I think that was put in by Power Engineering.

[Dan881]

Doesn't look like to much to worry about as said most likely just grease/dirt picked up from around the system. If your that worried suck it out as said above and top back up then just keep an eye on it

[Scott.T]

Originally Posted by Red Baron

Different coolants for the different materials used in cooling systems, copper, steel, aluminium, rubber, silicone, I know VW are very specific about the orange G12 coolant you should use in their cars. Saying that my Scoob has green in it, found that out when I bought some red to top up after doing the top hose. Based on the history I think that was put in by Power Engineering.

But then VAG are very specific about their oils too. Repackaged and repriced.

Gone are the days when you have to hunt down the correct coolant because you have an aluminium cylinder head.

[Scott.T]

You would never of got all the coolant out during a drain down in the same way you can't with an oil change.
It's probably just a little mixing.

[Ginola]

I would not worry about that on top of my coolant, looks pretty normal to me, as above residue from the last lot of coolant in there, general bits of grease etc
If you dip your finger in it and it comes out black then start to panic (or milky and creamy!)
Other than that I would not stress over a tiny amount of contamination in there.

[555_Si]

Just use the car and stop worrying about it.

[Steve_PPP]

Cheers guys. She'll get a run to Brands on Sunday so hopefully no issues show up.

[munk]

i see this sort of thing alot at work with the trucks, when the add blue comes into contact with aluminuim parts, looks like some sort of reaction.. wouldnt worry to much..but there is specific coolants for specific engines still, as we are always getting reminded about it..