Pretty much what title says: August 2022 replaced cylinder head (+head gasket, valve cover gasket, exhaust header) due to repeated overheating on the previous one. Took it to machine shop and made sure it was good for replacement and everything went smoothly from there, but there's been smoke coming from the engine and exhaust since then. Had hoped it was just the new parts burning off excess oil from being new, but 8 months later nothing has changed on the smoke front.

Also been experiencing an oil leak since the replacement that seems to be coming from the valve cover gasket if that has any connection.

Car runs fine, but I've recently been getting worse gas mileage (was only filling up every 2-3 weeks, now every week and a half) and smoke has been getting into the cabin, seemingly through the glove box. Any help is greatly appreciated, feel free to tell me I'm a moron or anything if it's an obvious problem/fix, I won't be upset.

 

So the engine is smoking or is the smoke coming out the exhaust?. Oil leak at the valve cover or cam gear? Get eitherr some baby powder or flour, clean the engine and then sprinkle the flour or baby powder around the valve cover. Drive it for a few days and see where the leak is. Check your spark plug holes for oil leaks.