Blown Head Gasket Replacemnt

Without knowing the year and engine you have, we can't give specific details, but in general you have to remove everything attached to the cylinder head then follow a prescribed sequence of loosening the bolts holding the head to the block. You take the head off and check or have it checked to ensure it's still perfectly flat, as a warped head is one of the most common causes of a head gasket leak. If it's not warped too much it can be resurfaced back to being flat, but if it's too far out it would have to be replaced. If I'm replacing a head gasket, I always take the head to a machine shop to have it checked over. If you don't you may get away with just replacing the gasket, but then again you could just end up with the same problem if you haven't fixed the source of the problem.

After that you would use a new gasket and, following the factory requirements, tighten the head bolts in a particular pattern to the required torque setting. This may have to be done in stages, and may require an angle gauge as well on some vehicles; I don't know the specifics of yours.

Since the head contains coolant passages, you would normally drain the coolant system first then refill it when you're done.

All in all it's something that's doable by a home mechanic but if you're new to it you'll want to use a machine shop. You'll need a good set of tools as well; a torque wrench is an absolute necessity and a heavy duty socket for the head bolts is usually needed; I've broken two regular sockets trying to loosen the head bolts on a Volvo, so a impact socket is a wise investment before you start.

If you are going further with the disassembly of the cylinder head, you would also need a valve spring compressor to remove those. A head gasket set usually includes valve spring seals so if they're coming off anyway you might as well replace them; otherwise it depends on the age of the engine and the mileage as to whether they should be replaced or not.

And of course, depending on the timing setup chances are you'll have to remove the timing belt or chain. It is absolutely essential to follow the repair manual regarding getting the timing set up correctly when you reassemble the engine. Failure to do so means that best case the engine may not run, and worst case the valves can open at the wrong time, possibly destroying the valves and the pistons. Again, depending on age and mileage, you may want to replace the timing belt and water pump as preventative maintenance.

All in all, it's a big job; one that I've done several times but with the help of a repair manual such as one made by Haynes or Chilton it's very much doable. There are more high end manuals available by Bentley and factory manuals are usually available, but of course you'll pay much more for those. Obviously the factory manuals are usually considered the best and final authority but it's a trade-off with regard to cost.