For at least 4 years I could detect a faint smell of coolant in my 98 Tahoe and between services the expansion tank would go down. I searched for a leak and never found it.
Until I decided to replace the engine then I found a stain on the right head after pulling the exhaust manifold. See for yourself in the pic's below.
Lifting the body is way easier then working on it with the body in place. Didn't even have to break open the A/C or brake system.
The chassis made a great engine stand and parts bench.