Bought used. Burns oil at about one quart per 1,000 miles. Notice " click, click" noise after starting and starting to warm up, and then that noise quits. No noticeable oil leaks underneath vechile. No oil leaks on ground under vehicle while sitting for several days. No noticeable blue smoke coming out when starting. Good power, everything else works fine. Vehicle is in excellant shape.
I recently hauled a light fishing boat on smalll trailer full of duck decoys out to North Dakota. Drove there, about 500 miles. Drove on freeway and good highways all the way. On about 10-15 occasions had to go up rather steep hills. Truck wanted to go into overdrive on hills. Started using 3rd gear, when going up the hills. When arrived, the next day I found I was down about 2 quarts of oil. Had oil changed about 1500 miles before trip.
What should I do to check out why it is burning so much oil? And what do you think is the problem?