Losing power up hills.
 

New to dodge trucks and to 4we truck. So this my be normal. I live in very hilly area. If I start up a hill at 70mph it may drop Down to 60mph. If I kick into the passing gear it will speed up but I don't feel like I should have to go into passing gear. Is this normal or does it indicate a problem somewhere?

Gas mileage is still good mixed between interstate and highway is about 13. It doesn't seem to use any oil. It shifts through all the gears and the fluid level in the transmission is good. I've cleaned the iac along with the throttle body completely pulled it and cleaned it with a toothbrush and throttle body cleaner. There are no codes and the transmission was rebuilt less than 20,000 miles ago. I was leaning towards the intake plenum but thought if it was that my gas mileage would be worse than it is. The truck has 150,000 miles.

Just a little history on the truck it has new plugs,wires,coil,distributor cap, rotor button, catalytic converter, water pump , timing chain set, new alternator.

Any help would be greatly appreciated. Thanks

Have to ask, what engine?

I would check your plenum anyways, just for grins. Is it kicking down into 2nd from overdrive and 3rd, or just from o/d TO 3rd?

It's a 318. It kicks down to 2nd everytime. And then 3RE finally back to o/d. How could you check the plenum without pulling the intake.

Manually open the throttle valve body (butterflies) and shine a flashlight down there. Tell us what you see. Some oil? Pooling oil? Sparkling clean?

Okay so when I clean the throttle body about a week ago when I took off the tb on the bottom of it was a bunch of black build up and the same it looked like down in the intake but I didn't really see pooling oil I don't think. But I'm not sure would carbon build up look the same or different

It would look like thick, oily, goopy residue. Like oil mixed with carbon. Sounds to me like you probably have a plenum issue, at least.

Do you have to use the Hughes kit or just the gasket. How long will the gasket last vs the other

Some folks have used a GOOD quality gasket, gotten shorter bolts, and skipped the hughes plate. Haven't heard of any having to be redone, yet.......

How many miles on your truck?

Conventional wisdom, at this point, is that the new gasket does the trick. However, at the very least, I would use shorter bolts (or grind a tad off of your existing ones) as well, just for a little bit of insurance that you won't have to do it again.

That said, I went with the Hughes, just for grins (and I like the extra, extra insurance).