Head Gasket Leak

[MADMIKE]

Had both head gaskets replaced under warranty on mother in law's 2002 Subaru Outback 2.5L in May---what tipped me off was slowly dropping coolant level with no external leaks. Did UOA with Dyson Analysis which confirmed small coolant ingress. Coolant level is now dropping again so we took it back to the dealer--they said they pressure tested the engine for 4 hours and found no leaks--said they put in dye also to help spot leaks---they said it might just be an "air bubble" that was trapped. Does this make sense? Any thoughts on what to do next other than continue monitoring coolant level and if continues to drop do another UOA? Thanks for any ideas/info.

 

[Drew99GT]

Add Subaru cooling system sealer and keep monitoring via used oil analysis till the warranty is up. That's what I'd do so you'll have ammo if it shows coolent in the oil again.

 

[Cutehumor]

wow, your dealer sounds like the Nissan dealer I've been dealing with. pressure tested and found no leaks..put dye in, no check engine light on, no overheating. They can't find anything wrong. blah blah blah. They probably know there is a leak somewhere but don't want to spend the time/money to fix a tiny leak. Keep doing used oil analysis at every oil change as evidence and try the sealer like drew suggested.