Overdrive issue

[Jackson32]

I have a 1998 5.9L. Coasting around 45 to 50 mph the truck has almost no acceleration. It will accelerate but very slowly. If it hits it's step down the truck gets up and goes but not until it steps down. It also will send a rumble kinda like a vibration up through my ass if I step on the gas to rapidly. Only does it every so often. When your coasting the engine sounds really ruff. Not sure what it is. I've had people say it could be and overdrive switch problem.

 

[dapepper9]

45mph+ the trans will be in overdrive and won't like acceleration much. Press the button on the end of the shift lever, orange light will turn on dating od off, trans drops to 3rd, get to the speed you need, press the button again, light goes out trans shifts into 4th/overdrive.

I keep my overdrive turned off unless i get on the highway. Keeps temps lower and life longer with only a slightly annoying orange light.

 

[dodge dude94]

^+1

Also makes things interesting in town when everyone else is having to kick down to get movin.

 

[Jackson32]

Yeah but it picks up speed very slowly. Once I press the button it's fine, but the rumble is what gets me. It's like it's trying to kick into overdrive but wont. If I'm coasting and press on the Gas it'll rumble and if I let go and press on the gas again it will sometimes do it again. But if I slam on the gas without hitting the step down it won't rumble. The rumble is like a vibration being sent up through my seat.

 

[Jackson32]

Also the engine sounds real rough sounding.

 

[Jackson32]

Like it's struggling to get anymore power to the engine than it already has.

 

[dodge dude94]

It rumbles because you're opening the throttle without it kicking down, it's basically lugging. Normal condition in my experience.

 

[dapepper9]

Yep. 4th gear and overdrive are the same thing and at 45mph, that's what gear you're in. It's a high heat and trying to accelerate slowly without kickdown is like going from 2nd to 5th in a stick and trying to accelerate

 

[Jackson32]

Will my truck running off the Cadillac converter have an effect.

 

[KyleW2]

45mph+ the trans will be in overdrive and won't like acceleration much. Press the button on the end of the shift lever, orange light will turn on dating od off, trans drops to 3rd, get to the speed you need, press the button again, light goes out trans shifts into 4th/overdrive.



I keep my overdrive turned off unless i get on the highway. Keeps temps lower and life longer with only a slightly annoying orange light.

how's leaving it off in city driving affect gas mileage? any affect at all?


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[NightMares]

Will my truck running off the Cadillac converter have an effect.

Please explain. Did you put an engine in your catalytic converter? Is that what powers your vehicle?

If you're asking if a catalytic converter can effect the engine and cause symptoms related to yours, then yes it can. Normally it's something along the terms of an o2 sensor. Is it throwing any codes?

 

[Jimmy68]

Plugged cat con?

I run no cat.
Shifting is erratic. Some days it'll hold second even at 75mph until I let off the gas. Sometimes it's 3rd. Usually won't grab 4th unless I feather the gas. Sometimes no problems.

Vibration under power? Maybe a bad u-joint.

 

[dodge dude94]

Please explain. Did you put an engine in your catalytic converter? Is that what powers your vehicle?

I laughed way too hard at that

 

[dapepper9]

how's leaving it off in city driving affect gas mileage? any affect at all?


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I get about 9 regardless. I quit giving a damn a long time ago lol. I only track it to watch for sudden spikes and give me a max range estimate

 

[Jackson32]

I'd say it's about equal

 

[Jackson32]

I was thinking maybe having no muffler would cause a decrease in pressure buildup. Causing a lack of power to the engine.

 

[dapepper9]

No. Can lose some low end tq due to decreased exhaust velocity but you gain it back in mid to high range. Backpressure is a myth

 

[Jimmy68]

No. Can lose some low end tq due to decreased exhaust velocity but you gain it back in mid to high range. Backpressure is a myth

Dunno man. I had a 73 Plymouth Cricket with a hole in the muffler that lost an amazing amount of power till I fixed it.

 

[dapepper9]

Dunno man. I had a 73 Plymouth Cricket with a hole in the muffler that lost an amazing amount of power till I fixed it.

Because of the reason i posted above. Threw your exhaust velocity all out of wack

 

[Jimmy68]

Because of the reason i posted above. Threw your exhaust velocity all out of wack

Yup. Lost all back pressure.