I have a 2005 wrx blobeye which is low on coolant. It looks like its got blue coolant in the but as its so low, it's hard to tell. Anyway, I ended up getting the blue coolant. I'm now not 100%. So my question is, what is the right stuff?

 

Colour doesn't matter really,I use comma x-stream g30 which is pink/red. You need to find out why it was so low on coolant 1st,did you check on level ground? Did you check from cold? Did you look in the header tank or the overflow bottle next to the rad?

 

The radio is full. It was just low in the reserve tank. I checked when car was cold and on level ground. There are no leaks anywhere as well. What do I need to look for on the coolant bottle to make sure I've got the right stuff.

 

Dont mix colours. There is a lot of info out there stating that the 2 will react against each other. Might be a myth but personally I wouldnt risk it.

 

Mixing colours is fine but not types. You have Ethylene glycol and OAT (Organic Acid Technology). The colour of the coolant in no way relates to the type.
Never mix ethylene glycol and OAT coolants otherwise it will turn to jelly.

if unsure either check with the garage that last serviced the car or drain, flush and put new coolant in

 

This^^^^

And IF you have to drain and refill, do a search on here for "how to".

 

What would happen if it does turn you jelly? Just asking out of interest as I never knew this before.

 

If it hasn't been changed for 3 years; change it! First make sure there aren't any leaks or teh head gasket hasn't gone....no point changing coolant if its leaking!

Blue/green is not usually OAT and is usually a 2yr/3yr antifreeze. But there is no hard and fast rule.

When changing antifreeze flush out the rad , header tank, reservoirs, engine and heater matrix with a hose pipe so you know all the old coolant is out the system so then you will know that there is no problem with it mixing with the old antifreeze.


You can buy flushing/cleaning additives.

Two I use often are:

"Sol-x O.C.F" which removes greasy build up (its for oil contamination, but works well on other contamination too).

and

Sol-x or Forte cooling system flush...both of these are more of a descaler, but is good for treating after using the above.

For bad contamination, Flush system with water, add OCF to right concentration, run for a week, drian, flush. Refil using cooling system flush and run for another week. Drain, flush and then finally refil with 50:50 mix of water:antifreeze

 

That is what we call a hybrid OAT antifreeze, which is why it lasts for 5years. And it does usually mix with non-OAT.

But if it is mixed, the change intervals have to be reduced to 2years until its fully flushed.