Sorry my english, I'm try change my head gasket after see coolant in cylinder 1 and 2 with camera. my car was hard to start some times. now i disassemble, buy a head gasket and my question if i need send to resurface or just clean and assemble again.
Is this for the 2010 Prius shown in your avatar? Or a Prius v, the somewhat larger version Prius, which commenced in 2012? either way, the engine is similar if not identical. I believe it’s best to not be “machining” the head, basically taking off a thin layer of the cylinder head’s mating surface with the engine block. Start by checking the flatness of the head. Typically you’d use a machinists straight edge for that, place it against the head’s machined face at various angles, and see what is the maximum thickness of feeler gauge that can pass between the head and straight edge. the specification for flatness of the head’s machined face, and also the block’s, can be found in the last link in my signature (3rd Gen Engine…). the two other “head gasket” links in my signature will be of interest too. If viewing on a phone turn it landscape (horizontal) to see signatures.
Car care nut has several good videos. It has to be flat and the surface finish to original. Felpro makes a head gasket “for the repair environment.” CCN makes the point he has only one machine shop who dies the kind of work he expects. But taking to any auto machine shop, machining may not be up to standards. It would a difficult task imo to duplicate the Toyota factory machining for correct surface finish. I saw it on my Toyota truck. Beautiful to look at doesn’t matter, that’s easy.
Some heads need no machining (removal of metal), some need machining to ensure your new head gasket does not blow quickly while some heads are so bad they need to be replaced. All will be coated with carbon and all should have new valve seals. Send the head to an automotive machine shop who can professionally clean, check for flatness and cracks, change the valve seals and return essentially like new. That might mean no machining, machining or replacement. If the car burns oil fast (which is common on these engines), consider a replacement engine instead.
Thanks for your Tips, i have prius 2011 and prius V 2013, same engine, but i decide to send to machined. i will attach photos here when arrived. and post the new results after finished my job. I'm not mechanic, i never did that one in my life, but i like to do thinks diferent.
