truck issues again?

[webstertroy]

So truck has been running fine since being repaired untill a couple days ago.. Started thumping at take off again.. When it was in the shop they said I had a misfire on 3,5,6 but no codes.. They changed plugs and coils.. What yall think would make this fail again? Its doing the same thing..

[175gr7.62]

How did they know it was misfiring on those cylinders without a P0303, P0305, and a P0306 code?

[Nailhead]

What kind of truck is it again??

[webstertroy]

How did they know it was misfiring on those cylinders without a P0303, P0305, and a P0306 code?

They said there machine could see the misfire I am not to sure..

[webstertroy]

What kind of truck is it again??

Its a 2011 Dakota 3.7 with 99k miles

[Charles]

If it's doing the same thing, it's misfiring on 3,5,6....

I got nuttin!

Good luck

[webstertroy]

If it's doing the same thing, it's misfiring on 3,5,6....

I got nuttin!

Good luck

Lol

[Nailhead]

I would be willing to bet it is likely a knock sensor or one of the other sensors in the engine. There are several in there that relay to the ignition system when to fire and to adjust the timing. I bet one of your sensors is faulty which is causing a "misfire". Sometimes the knock sensors or cam position sensors will start to go bad or wear causing a "misfire" to occur, but its not outside of operating parameters so it doesn't throw a code.

My brother is a mechanic and see's these types of issues all the time. I will see if I can get him on the phone after work and pick his brain about it.

[webstertroy]

I would be willing to bet it is likely a knock sensor or one of the other sensors in the engine. There are several in there that relay to the ignition system when to fire and to adjust the timing. I bet one of your sensors is faulty which is causing a "misfire". Sometimes the knock sensors or cam position sensors will start to go bad or wear causing a "misfire" to occur, but its not outside of operating parameters so it doesn't throw a code.

My brother is a mechanic and see's these types of issues all the time. I will see if I can get him on the phone after work and pick his brain about it.

Sweet thanks!! There is no Codes showing also.. Just the thump at take off... And after they did the work it went away and is back now..

[Nailhead]

I still think it is a knock or cam sensor, or something is messing with that bank. Notice how they said 3,5,6 all cylinders on the same bank. How long ago did they replace the coils and plugs?

[175gr7.62]

What they changed probably didnt do anything. You probably saw the improvement due to them resetting the computer and immediately after you picked it up it was running on the pre-programmed parameters stored in the ECU. After the computer started trying to "learn" the problem is back......I concur that you probably have a faulty sensor or possibly an injector somewhere, not necessarily a knock sensor.

A quick check would be to disconnect the battery for a few hours, touch the positive cable to the negative, and hook everything back up. Go drive it and see if the problem is present immediately but it comes back after 10-20 run cycles. If it does, you have a sensor sending bad data to the ECU. If the ECU gets bad data, it will send bad info......garbage in, garbage out.

[Rubi513]

I had a problem with my jeep one time where it would run real rough and not have any power. It would throw misfire codes.
After changing the coil pack and spark plugs it started doing it again.
Ended up being a bad catalytic converter.

[webstertroy]

I still think it is a knock or cam sensor, or something is messing with that bank. Notice how they said 3,5,6 all cylinders on the same bank. How long ago did they replace the coils and plugs?

about 3 weeks ago...

[Nailhead]

He said pull all the plugs and see if they are darker on one side of the engine than the other. Says its hard to tell without having it on a machine. Says it could be a bad O2 sensor causing one side to run richer than the other.

[Todd-ty729]

What they changed probably didnt do anything. You probably saw the improvement due to them resetting the computer and immediately after you picked it up it was running on the pre-programmed parameters stored in the ECU. After the computer started trying to "learn" the problem is back......I concur that you probably have a faulty sensor or possibly an injector somewhere, not necessarily a knock sensor.

A quick check would be to disconnect the battery for a few hours, touch the positive cable to the negative, and hook everything back up. Go drive it and see if the problem is present immediately but it comes back after 10-20 run cycles. If it does, you have a sensor sending bad data to the ECU. If the ECU gets bad data, it will send bad info......garbage in, garbage out.

I would listen to this man. He seems to know his way around a dodge.