Effect of low miles/car sitting on coolant.

Joined
Sep 20, 2014
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I am unclear on the effects of sitting on coolant. Are the corrosion inhibtors consumed by time, or my by miles (heat, greatly speeding reactions)?I plan on flushing the system and getting in wholly new coolant (or maybe only d/f). Here's the history as far as I can piece it together (prior owner not available so going on records I can find/stickers).

2004 Volvo S60 2.5t awd, 133k on it now.

111,000mi in 2011, timing belt change (has factory Volvo coolant in it, likely installed then - done at Volvo dealer)
125,500mi, 11/2016
133,000mi 10/2020, I believe it mostly sat from ~12/17 or shortly after until 9/2020.

So the coolant, which is OE Volvo blue, appears to have last been touched with the timing belt in 2011, 22k miles ago/9 years.

Flushing this is apparently a little tricky with a high likely hood of breaking the radiator and block tap plugs (replacements available), also introducing air into the block hard to clear. OTOH, cooling issues with these can lead to HG problems and I want to be careful with the coolant health. Can I test the anti-corrosion properties effectively, or should I just do a radiator drain/fill to minimize hassle. I was going to use Peak 10x for the corrosion protection qualities (it's compatible).

By the conventional wisdom on Volvo forums (Volvo itself is mum on coolant interval on these) - 5/6 years and 60k. So it's three years over due by the clock and 40k under by mileage.
 
Joined
Jul 14, 2020
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DFW Metroplex
Any deposits visible on the insides of the overflow tank? That’s usually a good sign the coolant is spent (or been mixed with an incompatible formulation).

3 years over isn’t terrible, but it’s more than I personally would like to run. If it were mine, and doing a drain/fill was possible, I’d replace it with fresh coolant just to be sure there’s no issue with it going forward.
 
Joined
Aug 30, 2004
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CA
I've been told that coolant deteriorates with age as well.

For the refill issue, invest in a vacuum coolant filler such as this one:

The universal ones work okay but the units that use application-specific caps work a lot better.
 
Joined
Sep 5, 2018
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I've been told that coolant deteriorates with age as well.

For the refill issue, invest in a vacuum coolant filler such as this one:

The universal ones work okay but the units that use application-specific caps work a lot better.

Have you used this refill kit? Does it work pretty good?
 
Joined
Jun 14, 2011
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676
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FL, USA
A few years and miles overdo is not a big deal.
I would do a few drain and fills with distilled water that way you can inspect after each drain if you are that concerned.
Then come back with coolant. The funnels that fit the top of the radiator work well to get air out of the system.
 
Joined
Aug 30, 2004
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Have you used this refill kit? Does it work pretty good?
I have not, but I have used a similar one from uview and currently own the snap-on one.

A few years and miles overdo is not a big deal.
I would do a few drain and fills with distilled water that way you can inspect after each drain if you are that concerned.
Then come back with coolant. The funnels that fit the top of the radiator work well to get air out of the system.
For the non-problematic applications I find the funnels to work pretty well. If the application is problematic it may take several tries with a funnel.
Generally, if the OEM specifies vacuum filling, I would proceed with caution.
 
Joined
Jan 22, 2011
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7,296
I think it is overdone. With distilled water, I go five years with the green coolant and 8-10 years with Ford orange on a 2003.. Coolant always looked good coming out. I have two 87's with original radiators, one original heater core and the other heater core was replaced in 1993. I go by time not mileage.
 
Joined
Sep 18, 2002
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5,591
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VA
Miles and time. Chemical reactions are taking place when the car is not running.

My belief is it is way overdue. Only use OEM and distilled water if you have to mix it.
Leave the heater temp to high heat. I would do 2 exchanges and make sure you drain
the block if possible.
 
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