Off-On Coolant Leak

I have a 1996 S-10 Blazer that has had a slow coolant leak for 4 years, and nobody can find where it is leaking. Numerous things have been replaced, all to no avail. I have to keep adding coolant.

What’s been replaced so far?
Has anyone checked the manifold gasket?
Has anyone checked the cylinders to see if they hold pressure?

The thermostat, cap, water pump, 2 water hoses, hose fastener, and radiator has been replaced. Mechanic said there was a slight leak in the manifold. Manifold gasket hasn’t been replaced. The cylinders haven’t been checked.

“Mechanic said there was a slight leak in the manifold.
Manifold gasket hasn’t been replaced”

I’m not quite sure why you don’t believe that this leak that has already been identified is the source of your “slow leak”. Why not have the manifold gasket replaced before venturing into a new area to explore for leaks?

Thanks!

Not to mention before engine damage - the internals of the engine do not like water/coolant even a little bit.

GM has had chronic problems with intake manifold gaskets - to the tune of a class action law suit or two.