so over the past couple of months ive lost 2 gallons of coolant. no visible leaks that i can see and no smelly coolant white puffy exhaust smoke. does smoke clear/white under acceleration but i think that may be because i have a bad CDR valve(?). during the day there is NO white smoke under acceleration but i can see it in the night time because of the headlights of the cars behind me. anyways
i pressure tested the cooling system to about 15 psi and exposed two leaks around my upper radiator hose and line from block to coolant filter. corrected those and then decided to make sure that the pressure holds. i put it at 13 psi and no more visible leaks. the gauge would SLOWLY lose pressure. It would lose about 1/2 pound psi in about 5-7 minutes. should i be concerned or am i over reacting? could those two small hose leaks have caused me to lose that coolant over such a long period of time? i can never get any coolant to stay in my reservoir as it would always seem to "disappear". i am going to drive it now for a week or so and see if i fixed it. i am just wondering if me losing that pressure slowly is a problem or not. thanks

 

That pressure should not be dropping. You've still got a leak somewhere... if it's a small head gasket or head crack, your exhaust may not smell particularly sweet especially with the diesel aroma.
See if anything's dripping off the back of your engine down onto the Y-pipe. Could also be a freeze plug especially the ones you can't see well (DAMHIK).
Have you checked out the heater core?

 

 

my radiator leaks at the top tank. did it with the original, and also does it with the new one.
same deal, overflow tank is always empty, so i don't use it. radiator if filled will slowly leak to 1 inch below the cap then stop and stay there. so i just leave it at the one inch below the top mark and call it good for the past 400,000 miles.

 

 

 

yea, two gallons is a little more than a minor leak. ...unless you are like me and only add it once every two-three years.

 

 

If it's like what mine did, it'll probably only leak under heavy load, or leak very very little.
Keep an eye on the oil filter when you remove it - If you see "clean spots" on the metal where oil kind of...pushes away, it's minor amounts of coolant leaking internally too.
I've seen that on two IDI engines with minor head gasket leaks.
In the case of my '93, I had a year from when I started seeing trails on the outside of the head gasket until it catastrophically blew, with constant bubbles in the overflow and 'steam cloud' out the exhaust.