first of all, on a 99 ram 1500 with 5.2, can someone please tell me where the oil pressure sending unit is? this will be the one that registers the guage on inst panel. not having problems, just like to know where everything is. 2nd is a heat issue. every once in a while, temp guage will register about 190, and heat will run you out. then most of the time, it wont get above 130, and freeze you out. this is after trips of about 50 miles or so. top rad hose is staying fairly cool, so i know it is not overheating. it is just that every once in a while heat is just warm, then the next time you drive it, it will burn you up. am i correct in thinking thermostat is sticking open? how hard is this to change? am fairly good mechanic, so am not afraid to tackle it, but just wondering.

 

oil sending unit is behind the intake mani to the left of the dist the thermo is easy just pull the two bolts in the houseing (follow the top hose down to manifold) and cut tab off the houseing you'll see what i mean when you get it out