From what I understand, those types of sealers will only work if the head gasket problem is in a specific way where the sealant will work. I would never use it on anything I own for fear of causing more problems. If there is no way in hell you would rebuild or replace the engine on the car it's worth a try, BUT I would first determine if you really have a head gasket issue.
Are you misfiring on any specific cylinders? That would be possible evidence of coolant going into that cylinder.
If coolant is getting into your oil you can take some oil out of the car (a few drips of the oil dip stick should suffice, but you might have to get oil on the dipstick a few times) and put it on some tin foil, heat it, and if there is any liquid contamination it will "sizzle," but if it is just oil it will only smolder. That is the easiest way to check without any kind of special tools and is actually a very reliable test to tell you if there is coolant mixed into your oil.
If you are misfiring on a specific cylinder, then you could then do a leak down test with an air compressor and an adapter to hook it up to the cylinder, take the radiator cap off (cool engine), put the cylinder at top dead center of the compression stroke and blow compressed air in, if it is blown you will very likely get coolant bubbling at the radiator neck. I would also recommend putting the cylinder at bottom dead center and blowing air in to test for any cracks in the cylinder walls if you don't get anything happening at TDC.
The other option is a block tester kit, which runs for $40 or $50, it is decently reliable but can result in a false negative, but should never result in a false positive (unless you actually draw coolant in and mix it with the liquid that comes with the test).
Perhaps someone on here more familiar with the 1st gen could tell you if you have any coolant passages in the intake manifold, I assume this wouldn't be the case, but it is always something to consider if the coolant could be leaking into the combustion chamber from the intake as opposed to the head gasket.
Worst case scenario it is a cracked cylinder block, which would present the same symptoms as a blown head gasket.
Are you misfiring on any specific cylinders? That would be possible evidence of coolant going into that cylinder.
If coolant is getting into your oil you can take some oil out of the car (a few drips of the oil dip stick should suffice, but you might have to get oil on the dipstick a few times) and put it on some tin foil, heat it, and if there is any liquid contamination it will "sizzle," but if it is just oil it will only smolder. That is the easiest way to check without any kind of special tools and is actually a very reliable test to tell you if there is coolant mixed into your oil.
If you are misfiring on a specific cylinder, then you could then do a leak down test with an air compressor and an adapter to hook it up to the cylinder, take the radiator cap off (cool engine), put the cylinder at top dead center of the compression stroke and blow compressed air in, if it is blown you will very likely get coolant bubbling at the radiator neck. I would also recommend putting the cylinder at bottom dead center and blowing air in to test for any cracks in the cylinder walls if you don't get anything happening at TDC.
The other option is a block tester kit, which runs for $40 or $50, it is decently reliable but can result in a false negative, but should never result in a false positive (unless you actually draw coolant in and mix it with the liquid that comes with the test).
Perhaps someone on here more familiar with the 1st gen could tell you if you have any coolant passages in the intake manifold, I assume this wouldn't be the case, but it is always something to consider if the coolant could be leaking into the combustion chamber from the intake as opposed to the head gasket.
Worst case scenario it is a cracked cylinder block, which would present the same symptoms as a blown head gasket.
