Just today, someone suggested that the Fiero’s overheating problem is probably the head gasket. If that is the case, there are only two options if I wish to keep the car. First, I could shell out $600 to have the head gasket replaced. Second, I could try adding a liquid sealer to the cooling system in hopes of stopping the leak. But do these sealers actually work? One Youtube mechanic says that he has had 80% success with a product called K&W Engine Block Sealer. Here are his thoughts:
Note how he ends his video. Sealing the head gasket leak is only part of the solution. The other part is finding out what made the engine overheat and eventually rupture the head gasket. He suggests that common problems include a clogged radiator (which flushing will not fix) or a non-working radiator fan. What he says makes sense and would certainly be less expensive than the other option.