'02 Discovery Head gasket problem

I have had an 02 Discovery for a year now and every since I got it, it has had a very slow water leak. Now that I am watching closely, I have to add about 1/2 quart to 1 quart of coolant every 400-600 miles, plus or minus, depending on how many short trips there are. I am pretty sure it does not leak at all just driving it. I made a couple long trips one week and put over 600 miles on it without the water level even moving. It does use a little more during the summer than in the winter here in Arizona.

I finally figured out it is a very slow leak off the back of the drivers side head, only right after you shut it off. It generates about 3 to 5 drops after turning it off that drip right onto the exhaust manifold and burns off. That is why I could never find any spots on the ground. Every once and awhile I would get a whiff of hot coolant, and I finally found it out by luck when I had a u-joint start going out and put it on a lift to check it out... heard the sizzle right after I shut it off and watched it slowly build up and drip 3 more times and stop. There is no water in the oil and no oil in the water... just loses a little water after the pressure builds up when you shut it off. For the cost of replacing a head gasket, I just cant justify that right now... I dont really want to use alumiseal or any other additives, would it be possible that re-torking the head would fix this or is that an equal possibility of making it worse??
Thanks for any input
Jeff  

The gasket on your vehicle may be a composite variant, if so it will be an early version which were well known to fail premeturely, LR fixed many of these over time, and within the warranty period. Here in the UK there were many problems with them, something as simple as not using the correct type or mix of anti-freeze caused problems, but a later version was upgraded to sort out the problems.

One other problem is fitting of aftermarket items, these were not the composite items, and wrecked many good engines, so always stick to the original; from memory i believe you cannot add cooling system sealers to engines fitted with these gaskets.