I am fairly new to the Dodge world, though I spent several years under the hood of my jeep and know my way around pretty well. Up until the transmission that is.
Recently picked up a 98 1500 with the 360 5.9L with 148k miles. All around seemed to be in pretty good shape. After pulling a 5k lb trailer to our new house, it seemed pretty evident that I have a Plenum problem. I have not had a chance to get under the hood and tackle this yet which I know is part of the problem I am about to describe.

Anyhow, today i went to get on the highway and everything seemed normal, until I came up to a little bit of an incline and the truck slowly died down to a crawl the further up the hill I got. By the time I was to the top I was going about 40mph (down from about 65). That alone seemed a little odd. Then as I went to try and speed back up the truck didnt want to move. RPMs were up about as high as I've ever had them and the pedal was to the floor, but the truck was still just barely crawling.

I ended up getting off at the next exit and took gravel all the way home as I was having trouble getting any sort of speed built up.

So since I know just about NOTHING about transmissions, what I do know is there is a definite plenum issue and some sort of vacuum issue. The A/C blows nice and hard and cold when under normal load. On a hill or under throttle the air stops flowing. I dont know if the PCV has anything to do with that or if it might just be a leak somewhere.

What do you guys think? Where should I start? BTW I'm broke as a joke...so this just sucks!

 

Remove the pre-cat O2 sensor, take it for a ride, if it runs better, that indicates a clogged cat. You can just hollow it out if you can't afford to replace it. (provided you don't have state inspections.....)

The A/C doesn't stop blowing, it switches to the defrost vents would be my bet. Check the faq section for the "Wild Vents" thread. Fix is in there.

 

Thanks HeyYou. You dont think its something related to the tranny? I can pull the sensor this evening when everything cools down. How hard of a job is it to hollow out the cat? There arent any inspections in Iowa so I can basically do whatever the hell I want to.

 

If your transmission is not shifting down somewhat it might be indication your MAP sensor is not properly reading.

I noticed that on my truck.. I really had to give it more gas or get into passing up some hills and so on.. replaced the map and it will drop down gears properly now.

Got mine off a guy on e-bay; was a Delphi.. for 22 bucks.. works great but he's sold out. Personally would not go for SMP aka Borg Warner.. Ive had some issues with alot of their parts being cheap-o lately..

 

It sounds a lot more like an engine performance problem to me, than a trans problem. The engine has to run right, for the trans to shift right.

 

Sounds like plenum is bad and a clogged cat like Heyyou said... when you towed that trailer though was overdrive on or off?

 

That's why I was posted about the Map sensor because my Dakota 5.2L w/ 44Re was sluggish up the hills; but once i changed map sensor out it actually downshifted when it should have been. That is what i was missing.. the map sensor data effects shifting as well.. telling the PCM when under certain loads and needs to down shift.

Or something like that. One other indication of bad faulty map is turning; the truck not always down shifting and feeling like your in 4 banger trying to accelerate unless you stomp on the gas.

New Map cured it for me

 

I turned it on and off throughout the trip. I was pulling from Northern OK to Iowa so the first part of the trip was relatively flat and the second half was quite hilly.

Thanks for all the quick help. Hopefully tonight I can pull that sensor and get back with a few updates. I sure hope you guys are right. I would hate to have to rebuild or really do anything to the tranny!

On a side note: If anyone on here lives close to the Des Moines area and wants to help with the Plenum repair feel free...the beer is on me!

 

I would rather have my beer out of the can/bottle/tap...... Unless of course, you are a good lookin' female. In that case, I will drink it however you offer it.

I'm in michigan though... that would be quite a trip.

 

hahaha yea that would be a long trip just for beer, and I think I would only let you have it "on" me if you were a good lookin' female. Or if I had enough of them myself before hand i might even settle for just a female.