Vortec engine water loss

I know that this has been covered before but I'm not that good with computers and can't find the info so sorry in advance.
I have a Blazer 4x4 1999 with a 4.3l Vortec engine which keeps using water.
I put about a pint of water in each day, however I can't see where it is going, the radiator is fine, the hoses are fine, the water pump looks fine, I have looked for signs of water tracking down the front behind the water pump and the AC compressor as well as at the back of the engine but can't find anything. I have put paper under the car to see if anything drops on it but nothing (I have taken the under engine covers off to do this).
The car starts fine.
If I do a short journey (say 20 miles) the next morning I put the best part of 1 pint of water in it, if I go on a 350 mile round trip, the following morning I put just about the same amount of water in.
I have checked the oil and it's not contaminated.
I need to sort this soon as the weather is getting colder and I don't want to be adding loads of antifreeze each day as that will end up getting very costly.
I read that the inlet manifolds have an issue but I'm wondering if there is anything else it could be due to not seeing any water on the outside of the engine.

Unless I'm missunderstanding you I didn't see were you were checking inside, passengers floorboard for heater coil leak. Do you smell antifreeze, do you have problems with your window foging a lot.Is your floor board wet. These are signs. And also water pumps will fool you sometimes. Sometimes they want leak until you're driving and get at runnig temperture. After they get very bad is when they show up sometimes.Good luck Fiserman

Hi, thanks for your reply, the inside of the car is fine no wet patches and no fogging up of the screen. I forgot to mention that I filled the radiator up one night and left the cap off the radiator and in the morning I had to put another half a pint of water in the radiator as the level had dropped and this was without starting the engine.
Also this has been going on now for over 8 months and hasn't got any worse but obviously it will, I would like to have cured it before it gets too bad weatherwise. I know what will happen, the leak will become obvious and I'll have to do the repairs in the snow!!!
Anyway thanks for your input.

Hi, thanks for your reply, the inside of the car is fine no wet patches and no fogging up of the screen. I forgot to mention that I filled the radiator up one night and left the cap off the radiator and in the morning I had to put another half a pint of water in the radiator as the level had dropped and this was without starting the engine.
Also this has been going on now for over 8 months and hasn't got any worse but obviously it will, I would like to have cured it before it gets too bad weatherwise. I know what will happen, the leak will become obvious and I'll have to do the repairs in the snow!!!
Anyway thanks for your input.

Sounds like your lower intake gaskets may be going bad which is a common problem on these engines. The factory gaskets are very cheap and the Dex-cool coolant slowly eats away at them causing either an external leak at the front or rear of the manifold or a slow internal leak. Have you performed a pressure test on the cooling system?

Hi, I haven't done a pressure test. What worries me is if I do the intake gasket and then find it is still loosing water I would have to assume it to be a small head gasket leak and I would have to replace the intake gasket again.
I'm leaning towards just biting the bullet and get a head set and do it all in one go, at least then I know that if it continues to leak after that it is not those items.
What is baffling me is that the oil isn't contaminated and that I can't find any traces of a leak on the outside of the engine.
Anyway thank you all for your input.

Had the exact same issue on a 98. Finally put it up on ramps, started it up and waited 30mins. Crawled underneath, finally found the leak. Hot engine was evaporated the small leak. Intake gasket. Fixed it, no more issues for yrs.

Whilst I still have all the under vehicle covers off I'll give that a go, certainly nothing to loose. Thank you.