XC90 antifreeze loss

croderique · Post by **croderique** » 17 Jul 2021, 11:24

We purchase a used XC90 in May and it continues to require about a half quart of antifreeze per week. We took it to a Volvo mechanic who checked it over, did a coolant compression test and couldn’t find any leaks.
Any ideas from the forum would be appreciated.
Thanks
Chuck

croderique · Post by **croderique** » 17 Jul 2021, 11:26

It is a 2006 with 124k miles.

Post by **cn90** » 17 Jul 2021, 12:26

If no external leak on the driveway then...

- Check the heater core, which is notorious for leaking after 100K.
- I wrote a DIY here...

DIY: 2005 XC90 Heater Core Replacement

viewtopic.php?t=82726

wanderdüne · Post by **wanderdüne** » 23 Jul 2021, 10:47

Sometimes they leak but don't drip at the base of the thermostat housing, the top hose, look for crust there.

Post by **ggleavitt** » 23 Jul 2021, 15:08

2006 had 3 motors in North America alone, there is no way to guess this in advance. It's information that's easy enough to append permanently into your signature (add a 2.5T, T6, or V8) then no one needs to ask. FWD distinction (if it's not AWD) helps as well. Can do as signature and/or profile, both will be noted on all of your posts.

Capndirk · Post by **Capndirk** » 28 Jul 2021, 11:28

You don't mention the engine, but I had a phantom leak on my 3.2. It needed half a liter every month or more. I finally saw a build-up of fuzz at the lower hose connection, and a greasy build up on the body wayyyyy below it. The coolant bottles are notorious for leaking there (and elsewhere). It looks like the clamp is at fault, but it is actually the bottle.