Ram 5.9l Power

Braeden Clark

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Williamsport PA
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1999
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5.9l
So I just recently bought a 2000 Ram 5.9l with the auto trans. I could help but notice that it does feel a little... slow. Truthfully it does feel slower then my Jeep 4.0l. Which was also slow. How do these things normally feel as far as power? As a side note, I plan on replacing the cat as I am unsure if it's ever been done. Also I am not sure it the plenum has ever been done. I tried to look in the intake. Has oil obviously but I'm not sure if that's normal oil for a high mileage engine. Truck has 202k miles.
 

Fatbob Frank

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Restrictive exhaust or a bad cat will rob power.
A good tune-up helps too.
While pretty low on power compared to a Hemi, the 5.9s I've had always seemed up to the task in whatever they were in.
 

Bear_Gibson

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5.9 magnum
Search death flash and Torque managment. As long as you have faith in your transmission, a good tune will wake up these trucks.
 

scrounge

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Similar problem with my '99 318. Oil is visible when I look through the throttle body, which indicates that the plenum gasket needs replacing (it comes in a kit with the rest of the intake manifold gaskets). You might want to do this before replacing the cat, as oil will get in the new one if you don't. Until you replace the gaskets, check the oil level every few hundred miles, as consumption can be major if you do a lot of freeway driving.

I've had to replace plugs more than once, as they tend to foul -- 30K is the recommended interval. I also had to replace the cap and rotor, but so far the wires are ok.

Some sensors can affect performance. I had to replace the upper O2 sensor. Its wires were frayed near the sensor.

My first replacement was the air filter, and when I removed the intake tube, a clump of dirt fell to the ground. It was probably a mud dauber's nest restricting airflow, as I had to remove 5 or 6 of them throughout the engine bay. My air box had cracks, so I replaced it with one from a junkyard. Make sure the large clamp holding the air box on the throttle body is secure. It's also good maintenance to clean the throttle body itself and replace that gasket. I did so over the winter. The IAC in back of the throttle body can get sticky, so clean it, too.

You might also check for any vacuum leaks.
 

Braeden Clark

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Williamsport PA
Ram Year
1999
Engine
5.9l
Similar problem with my '99 318. Oil is visible when I look through the throttle body, which indicates that the plenum gasket needs replacing (it comes in a kit with the rest of the intake manifold gaskets). You might want to do this before replacing the cat, as oil will get in the new one if you don't. Until you replace the gaskets, check the oil level every few hundred miles, as consumption can be major if you do a lot of freeway driving.

I've had to replace plugs more than once, as they tend to foul -- 30K is the recommended interval. I also had to replace the cap and rotor, but so far the wires are ok.

Some sensors can affect performance. I had to replace the upper O2 sensor. Its wires were frayed near the sensor.

My first replacement was the air filter, and when I removed the intake tube, a clump of dirt fell to the ground. It was probably a mud dauber's nest restricting airflow, as I had to remove 5 or 6 of them throughout the engine bay. My air box had cracks, so I replaced it with one from a junkyard. Make sure the large clamp holding the air box on the throttle body is secure. It's also good maintenance to clean the throttle body itself and replace that gasket. I did so over the winter. The IAC in back of the throttle body can get sticky, so clean it, too.

You might also check for any vacuum leaks.
Yea I gotta dig deeper into checking my plenum. Did a few tests with nothing solid. Did look down there super quick once and saw a little but couldn't tell if it was normal or not. Gonna check again and see. It did seem to lose a bit of oil over a few hundred miles so I wouldn't be surprised tbh
 

Spike95

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Houston
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2001
Engine
5.9
Unless you have really big tires on it, the 3.92 gear usually feels fairly peppy... Maybe not compared to newer trucks that are getting over 100 more horsepower, but not slow. Then again, if you are rolling on 35”+ tires, it would feel sluggish.
 

Braeden Clark

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5.9l
Unless you have really big tires on it, the 3.92 gear usually feels fairly peppy... Maybe not compared to newer trucks that are getting over 100 more horsepower, but not slow. Then again, if you are rolling on 35”+ tires, it would feel sluggish.
It's running on 33s. I'm thinking it may be related to the cat. Sounds like there may be a rattle in there. I think its the stock cat with 202k miles. Maybe also have a plenum leak but will dig into that deeper here soon.
 
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