Dodge Repair: 98 Dodge Ram 1500 4X4 318 5.2L standard..., dodge ram 1500, losing coolant

Question
Hi,
My Dad's truck seems to "diesel" when going up hills or getting on it up an incline. It sounds clinky when putting a load on it, like the lifters/valves are working overtime. I think he was losing coolant ever so slightly also. What are some possibilities as to why it strains going uphill or increased workload? It bothers me, but not him! Thanks alot.

Answer
its called spark knock  and there is a computer update to help correct this issue. A dealer would need to do the updating. The coolant leak could be from intake gaskets leaking I see that quite often.I live in the Atlanta area I would be glad to look at it for u.