does opened coolant have a shelf life?

[sky jumper]

I think it is generally accepted that air in your cooling system can cause problems, including gelling of the coolant itself (this was the issue with early Dexcool I think).

so, if you open a bottle of coolant and only use 1/3 of it, how long can you let it sit on your shelf before it goes bad? do some coolant have a higher shelf life? I'm specifically interested in Japanese coolants.

 

[Vilan]

Last year I replaced my coolant using a very old half-empty bottle of green coolant I found in the garage. I would estimate 10-15 years old. No problems so far.

 

[toocrazy2yoo]

No offense to Vilan, but at $12.00/gallon ( for top of the line, anyway), why keep the stuff around, other than as top-off, for longer than your next flush and fill? DexCool wouldn't like the air in the head space in a 2/3 empty jug, in any case. Plain old elylene glycol? With high silicate? Expect the silicate to fall out of solution in a couple of years. Unopened G-05 is ok for a long time, but a partial? No idea.

 

[Vilan]

No offense taken. I agree there's no point buying more than you need. This was leftover coolant my dad bought for his car long ago and never used, so I took it, cheapskate tightwad that I am.

No idea how well G-05 would survive 10 years. But the fact remains my ancient high-silicate green seems to still be fine. I didn't notice any silicate fallout in the original container. Yesterday was the one-year anniversary of when I changed my coolant, still runs fine. Maybe just lucky.