What would you do? Low coolant

[specblib06]

I recently noticed that my overflow reservoir was completely empty, and after opening the radiator cap I couldn’t see any coolant. Obviously there could be a leak though I haven’t noticed anything and am thinking that I just need to top up both the radiator and overflow.

My only concern is with mixing coolants with whatever is currently in there. I’ll be getting a full drain and re-fill done when I can but am hoping to get me through until my next service.

Would it be fine just to fill up both the radiator and overflow with generic green Supercheap coolant? Or even distilled water? H6 engine, from what I remember, manual specifies 50/50 water and ethylene glycol.

[Yowie]

Distilled water won't do any short-term harm. Longer term the lack of corrosion inhibitors might be an issue. Also, if it's leaking somewhere, water wont leave the kind of tell-tale white staining that coolant does, making it harder to diagnose the problem.

My subi runs on generic green coolant (blended to whatever concentration with water - I just get it from the mechanic in self-supplied milk bottles. There is a good chance yours runs on the same green coolant, but it's easy for me to say that because it isn't my car.

[specblib06]

Distilled water won't do any short-term harm. Longer term the lack of corrosion inhibitors might be an issue. Also, if it's leaking somewhere, water wont leave the kind of tell-tale white staining that coolant does, making it harder to diagnose the problem.

My subi runs on generic green coolant (blended to whatever concentration with water - I just get it from the mechanic in self-supplied milk bottles. There is a good chance yours runs on the same green coolant, but it's easy for me to say that because it isn't my car.

Thanks. I’m happy to just buy generic green coolant and top up both the radiator and overflow but my only concern is mixing it with whatever is currently in there…might just top up with green coolant anyway and hope for the best

[Yowie]

On my limited understanding, the "mixing coolant" issue refers to mixing different types. I forget if Red or Blue is the odd one not to mix with Green, but mixing Brand X Green and Brand Y Green should be fine.

You can probably research that on the internet to get a better sense of it.

[nvmylh]

I'd be more worried about the upcoming headgasket replacement than coolant types if your car has an EZ30!

[bigBADbenny]

Doing a complete bleed would be essential.
viewtopic.php?f=16&t=36458

[RX25SE]

If your coolant is low, then it would suggest you have a leak. Until the leak is repaired, the safest option is to keep the system topped up with plain water. Yes this dilutes the coolant but that is a better option than mixing coolants.
The colour of the coolant does not determine the type of coolant (it's only a dye) so it's always best to add only the identical coolant if known.
Once the leak is repaired, flush and replace the coolant.