I recently purchased a '99 Sahara, so far, so good! However, I have noticed that if I leave her idling with the air con on for about 10/15 minutes, when I am out of the truck and have left the dogs inside... the cooling temp. goes up to over the 100c. When driving, everything is normal. Wondering if my idle revs are a bit high or could it be a pump problem. I have had the system flushed out and refilled with additive.