I just got a new to me 6.2 1/2 ton truck. I have noticed that it is not exactly peppy. At low end this is not a problem, but when I get it up to 60ish it does not pull hills well and I realy have to get into it for it to kick down into Passing gear. I pulled the air cleaner and it was filthy. So it got a new one. I have it apart right now because the pass side wheel berrings were not preloaded and was causing some vibration. Parts house gave me the wrong parts.

Is there anything else I should look for? I am pretty new to diesles and don't know what can cause these problems. I did put in some diesle injector cleaner and that seemed to help initaly.

One other thing, The oil pressure runs a bit below 80. every now and then durring idle or constant rpm driving the pressure guage will peg pas 80 sometimes it just sits there and sometimes it bounces. Funny thing is if I rev it a bit, it drops to normal. Is this an issue or just a bad sender or guage?

What year is your truck? Most 1/2 ton trucks have issues with power loss due to the egr getting the intake filthy dirty. Good mod is to get a heavy duty intake, easy to tell because it is completely open, no piece of crap egr obstructing air flow. Do a search on ebay motors for 6.2 diesel and look for non egr intake manifold. This change alone can net 15 rear wheel hp. Other issue could be fuel filter needs changed and figure out what gear ratio you have. Some half tons have 3.07 or 3.42, best is 3.73. Good luck.

Oops It is a 1983 Chevy. I have a spare engine with the non egr style intake, What do you do with the vacume hoses whe you change it out?

you can just disconnect them or plug the hose. Later you can remove the solenoids and brackets to clean up your engine compartment. There should also be a vacuum hose that goes to an exhaust flapper valve in the driver side manifold and I believe it fails open so I think that can also be disabled. When you replace manifolds, I would clean out the intake ports of the heads as well as possible and make sure to use intake gaskets with the stainless steel crossover block offs for the exhaust ports on the heads. Specify J series engine.;)

If you don't want to exchange your manifold then you can cut off the EGR base, weld the hole shut, and re-install the plate on the manifold. That is what I did and I also cut out the butterfly in the left side exhaust manifold plus I put in the solid manifold gasket since I had to remove the manifold for another reason.

If you don't use the solid gasket then the passage thru the manifold acts as a balance between the two exhaust manifolds. I didn't want the exhaust flowing thru adding heat to the manifold so I did use the solid gaskets. Engine power or torque is higher by having the balance. So I had a muffler shop connect a balance pipe between my dual exhausts to get my power back.

The proper way to install a balance pipe is when you put on new exhaust pipes. You paint the exhaust pipes and then go for a fast drive. There will a hot spot where the paint burns off and that is where the muffler shop should install the balance pipe. Mine goes under the cross member where the manual transmission rear mount is located.

Appears the bulk of it was the air filter. It will cruise at 70 now. Still slow to get there, but at least I have an acceptable top speed.

Any Ideas on the Oil gage problem. It seems to be getting better but when it does it, it is worse.

change the sending unit. Oil pressure should be 35-40 at cruising rpm.;)

I got a sender for it, just have not put it in yet. It runs on the notch under 80 and only flucuates about 1/8 inch travel up. Then on occasion pegs out.