My daily is a 2007 Subaru Outback with 215k miles, Manual Trans. I recently had a head gasket and timing belt / pulley job done 10k miles ago. Car runs good however I am starting to hear slight valve/lifter ticking noise at idle. I took the car to my mechanic (who previously did the HG job) to listen to the noise and he didn’t think it was significant enough to repair. I noticed after a fresh oil change, the noise disappears for a little while. Would it be a good idea to run Sea Foam in effort to clean the valve/lifters? Do you recommend any other product? From my previous experiences with my mustangs, a lot of these oil additive products can cause serious oil leaks.
I wouldn't run Seafoam through your engine, but I would try using this https://rislone.com/product/high-mileage-engine-treatment-4102/ or this https://rislone.com/product/engine-treatment-100qr/
I've used the high mileage formula in my own Subaru and it made it much quieter!
I've heard and seen Scotty talk about this additive https://lucasoil.com/products/engine-oil-additives/low-viscosity-stabilizer but I don't personally have any experience with it.
You've spent a lot of $$$$ on your Subaru to keep it going and I hope you can find a product that works!
do try the Lucas but those are notorious for having lifted problems as they age with that mileage all the hydraulic lifters are probably on the verge of eventually wearing out but they can make noise for quite some time and still run okay
