I have a 1500 series 94 RAm, 3.9 manual. It runs very well, however it seems to lack power. After 60mph, in 4th or 5th gear, i cant get much more speed. The pedal all the way down but it still just creeps. I am not sure when the last tune up was because I just got this vehicle and it was my Dads friends who passed away, so I cant get a lot of information.

Also, the oil is dirty looking, like a brown muddish color, maybe rust particles in the oil? I changed the oil, ran it for a while, and checked it again. It wasnt as bad as before but was still not the clean oil as i just put in, a little muddy looking. I checked under the radiator and oil cap, there is no white crud and the coolant consistancy is fine. Also, the previous dip stick had broke off and what remained of the one in there was very rusty. Took the part where the dip stick goes in and took it right off the truck but there was no broken part of th stick in there.

any help would be great! thanks

 

muddy brown is not good, there might be a blown head gasket, sounds like water in the oil. I'd swap the oil a 2nd time to flush it all out, then monitor it. give it a tune up with brass cap and rotor and ngk plugs. use good wires on there too.

on a truck that big, i'm not supprised it has a hard time after 60 mph... might want to look into some performance mods if you need more power (assuming the engine is all good).