So I got the tranny rebuilt and shifting great.

Drove from Utah to Oregon, and did great at first, then it seemed like the truck didn't want to get over 3k rpm, and when I really gave it gas it would kick down and make a loud noise, sounded like exhaust leak, and cel would flash till I let off throttle.

But it still was bogging. Vacuum leak possible?

Thanks!

 

sounds like a cat disintegrated to me.. pull your upwind o2 sensor and see if it runs any better.. just take it out and unclip it, and drive a little way to see.

 

Ya? 105k miles. Never replaced it yet.99, 1/2 ton, 5.2. it sounds like rattling/air leak right about 2k rpm. But I'm also getting my vents switching to defrost when accelerating sometimes, and coming back after letting off.

 

I do believe that a plenum fix, cat replacement, and full tune up is in order.
Maybe even check valves for your a/c.

Read through most of this thread:
https://dodgeforum.com/forum/2nd-gen...um-thread.html

 

you're describing classic blown plenum gasket symptoms..

wild vents: loss of vacuum, culprit: vacuum line somewhere, canister, or blown plenum..

rattling: pre-det 'pinging'.. blown plenum can cause this.. especially under load..

blown cat: due to oil in combustion chamber being blown into the cat, will clog a cat up quick like.. oil in chamber due to blown plenum gasket..

if you're in this bad a situation with the plenum gasket, your upwind o2 is likely toast too..

 

Thing is, there is no oil consumption at all. I'm gonna check for air leaks, change plugs and wires. See what that does.

 

So you are saying that since I did the plenum fix and still have the wild vents under acceleration like chadwall described....that my cat is clogged (no doubt with as much oil that was in my intake manifold). Or that I have a vacuum issue? Where would you start the diagnosis process?

 

I'm gettin a can of ether, quarter throttle it, and start spraying vac lines. Fine leak when it revs..

 

@Mudshack - The cat and vents are not related, at least it sounds like you are under that impression in your response. Do a search for wild vents and it will steer you in the right direction for that. I had the link but I will have to track it down. Usually it's just a check valve in the vacuum system that causes that. The plenum issue would clog the cat over time and prob fry the upstream O2 sensor.

Give me a bit and I can track down the wild vents thread if you cant find it. Really common problem on our trucks.

 

@ Ramzy - Thanks. I thought I was crazy thinking that the exhaust of the truck would be connected to the air flowing into my cab. Unless Kavorkian designed the truck. But hey....I don't put it past the designers at Dodge. I take everything at face value now and ask a ton of questions.