I drove my new truck to the body shop today and had a couple of problems along the way. The engine started overheating and jumping back and fourth between 200 degrees and 240 degrees, finally it stayed at normal operating temperature and remained there until i made it to the shop. Also I couldn't be sure because i wasn't on the highway, but i don't think the truck was shifting into 3rd gear. I was pushing 3200rpm and doing about 50-55mph. Could things be acting funny just because the truck hadn't been driven for about 3-4 months? Just looking for some info, i should have the truck back by the end of next week.

2000 Dodge Ram 1500 Sport 4x4, 102,600 miles, 5.2L v8, auto

 

The overheating could just be a sticky thermostat or a bad coolant temp sensor; I'd check the thermostat out first.

 

Im thinking it could have been just air in the system, but im just looking for some more ideas before i drive it home next week.

 

sounds like your OD wasnt working. 3200 is a bit high at that speed, i guess is depends on tires and gears too
my truck runs about 1750 rpm's at 65-70 mph

 

Could have been that too. When you get it back, make sure the system is burped.

 

Any idea on what would cause the OD to stop working?

 

Tranny could be starting to slip, I'd check to see if any tranny codes are in the computer.

 

i had an issue where my truck wouldnt go into OD and mine was because the transmission didnt get enough vacuum to put it in OD due to the bad IAD and TPS but if you dont have any issues with high idle or fluctuations in the idle it could be just a vacuum issue somewhere... and the thermostat could be on the fritz like everyone else said or a possible issue with the radiator

 

Im hoping its just something simple like the tps or tranny speed sensor, but i dont know until i get it back next week.

 

Hows the tranny fluid? possibly from sitting so long it may have lost some fluid?