2005 XC70 2.5T Coolant Capacity Topic is solved

iamhives · Post by **iamhives** » 30 Oct 2021, 15:25

I have searched various places and can't get a definitive answer! I also looked in my owners manual and for some reason it states all other fluid volumes except coolant?

I read various numbers from 7L up to 9L. I have an 2.5T and the most often quoted number is 8L but wanted to verify since there seems to be lots of divergent information out there.
Reason I want to know is I'm going to be flushing completely with deionized water and need to know how much 100% coolant to add in the last flush/fill to get the 50/50 proportion.

Post by **Blacklab467** » 31 Oct 2021, 15:53

I just did mine. After a full flush I added about 4 litres of the blue concentrated Volvo stuff and about 2 litres distilled water, I’m guessing there was about 2 litres left in the engine of water before I added the coolant because my tester showed it was good down to -37 C.

iamhives · Post by **iamhives** » 31 Oct 2021, 17:25

Been doing more coolant research. Its a controversial topic! It seems while its not ideal, HOAT and OAT and be mixed and will not result in a chemical reaction? And while our old Volvo's used HOAT originally it seems newer cars us OAT and that its preferable or European cars ? So is it OK to run OK to run OAT (e.g. in my new cars case Peak Pink - which is OAT) in our P2's?

Post by **erikv11** » 31 Oct 2021, 19:07

I know it's not really what you asked but: I would run Zerex G-05 (HOAT, reasonably cheap, easy to get locally almost anywhere) or the Volvo coolant (similarly cheap from FCP Euro, but have to wait for shipping). I don't mean mix them - run one or the other.

About cooling system volume, I have been going by the 07 XC70 user's manual (total capacity 9.3 quarts = 8.8 liters). This does mean you need to pick up and crack into a second bottle of coolant.

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iamhives · Post by **iamhives** » 03 Nov 2021, 21:09

Just to close this out. I ended up flushing multiple times (maybe 6) with distilled water, letting teh water cycle thru the engine with thermostat open each time. Then on the final flush let as much distilled water drain as possible from the radiator petcock (about 4.5L) and added 148 fl oz (1.16 gallons, 4.38 L) of Volvo coolant. The resulting mix had a specific gravity reading on my refractometer that indicated -45C freezing point which based on graphs I found for ethylene glycol indicates about 55/45 mix. Doing the math that means the overall capacity is 8L. Obviously not exact but certainly in the ballpark. If I understand it correctly while 55/45 lowers the freezing point more than 50/50, it reduces the specific heat capacity. I also believe anything more that 60 or 65% coolant and the freezing point start to rise again so 50 - 55% is about right. All a little too precise I know but now I know where I stand I will top up as necessary with distilled water until the dilution goes down to 50/50.

Post by **abscate** » 04 Nov 2021, 00:50

You have to live in a really pathological place to not get away with a single gallon of coolant in a P80. We very rarely dip below 0F here so running 40-44% coolant is fine.

Wind chill is irrelevant to coolant planning btw, we had a ( non Volvo ) dealer SA who used to upsell coolant changes based on wind chill.

Post by **jonesg** » 04 Nov 2021, 14:53

abscate wrote: ↑04 Nov 2021, 00:50 You have to live in a really pathological place to not get away with a single gallon of coolant in a P80. We very rarely dip below 0F here so running 40-44% coolant is fine.

Wind chill is irrelevant to coolant planning btw, we had a ( non Volvo ) dealer SA who used to upsell coolant changes based on wind chill.

yeh "Feels like" , thermometers don't feel or fear anything.