After a blown head gasket was repaired on your '94 Buick Skylark 2.3 why would the fuel consumption be high and loud valve train noise come from the engine?

After you replace your head gasket your compression in that side will be higher, I highly recomend to anyone that has to replace a head gasket that they do BOTH sides. With all the electronic checks that happen in newer vehicles a difference in compression can cause confusion in the electronics.

poor fuel mileage try changing o/2 sensor sometimes blown head gasket wrecks sensor and causes poor gas milage