is it very difficult to replace a head gasket on a 2004 elantra

Worked on an Aurora, basically the same, aluminum head, not hard to do, don't know why replace the radiator, a shop can clean it for you about 75 bucks, u'll need to replace both head gaskets, and torque both heads in proper sequence (basically start in center going in a circle) check the library books . hope this helps

Hi pepperoni, "easy" and "not hard to do" is a relative term. Sure, if you have proper tools and knowledge, it's not difficult but you are still talking about major work, dissembling the top end of the engine. It's expensive to pay a mechanic to do and time consuming for a do-it-yourself.. I agree with you about the radiator 100%. and your explanation of torquing head bolts. Very important. They may have said the radiator needs to be replaced because it had gotten over pressured to the point the cap relief didn't have time to dump coolant out in time to keep it from breaking something.

If the gasket needs replacing, the head or block mating surface may be warped. Be sure both are cleaned of old gasket very thoroughly. Then, take a straight edge and "feeler-gauge" to verify there is no warp, especially where the metal is narrowest. The books should show how and say how much it warp is acceptable. These steps are why I say replacing a head gasket is not easy, but it can be done DIY with care and a little study.