Topic: anyone good with late model dodge trucks?

[evinrude7]

posted this on the dodge ram forum.  thought why not post here.

2007 dodge ram 1500 hemi 5.7 4x4 w/545RFE trans.

been having a bucking/rough shifting/miss feel for about a year. NO CHECK ENGINE LIGHT.  it gets worse and i try one fix then it gets better for a while then gets worse and i try another fix. it's better then worse again. on a 10 mile trip it might do it 10 times. usually happens when i'm feathering the pedal just cruising along 45-65. did notice from 1st to 2nd gear this morning it had sort of a delayed shift once.

never slips. just a buck.

so far i've replaced the crank sensor, plugs (one of which was loose, far back one i may have forgotten to torque down on last change), throttle body taken off and cleaned, map sensor cleaned or replaced can't remember, trans service with filters.

these were all done after the truck began to act up. after the work it ran fine. months later it would act up again and i would try the next thing (as listed above) then it would be fine for months or i'd barely notice a little miss feeling once in months of driving.

spoke to a mechanic who said so you performed a trans service and it fixed the problem for a while then it came back? yes. so he said take it to a place that can completely suck the fluid out and replace. did that earlier this evening. bucked once on the way home.

any help appreciated. what's throwing me is there's no CEL. no codes to go by. which makes me think it's not a sensor.

thanks

[BomberMann650]

My 5.9magnum Ram bucks every once in a while.  My buddy said he heard a cylinder misfiring at idle.

Since it’s a seldom occurence - i suspect it’s likely part of whatever ignition management system dodge concocted.  I’m tempted to try a performance chip and see how the truck behaves with a remapping.

Rough/oddly staged transmission shifts seem to be another part of the Ram trucks charm.

[evinrude7]

this particular rough shift is not charming.  seems it could be damaging if it keeps up.

[jgger]

You can keep throwing parts at it................or find someone with a good scan tool that knows how to use it. With the advent of computers in vehicles a lot of the old diagnostic tricks don't work any more. With a good scan tool, not just a code reader, you can check pending codes and a host of other systems on the truck.

It could be something as simple as a loose/dirty ground or a harness plug that isn't tight, heck it could even be a chaffed wire somewhere. There are quite a few things like that that can make the computer go goofy on you. Maybe you will get lucky and accidently stumble on changing the right part, but by the time that happens you could own a real nice scan tool and be money ahead.

So like Dirty Harry said "are you feeling lucky, punk?" JK  Good luck on the hunt.

[BomberMann650]

$125 for olympia dealer diagnostic

[TwoTired]

I don't know the answer.
But have you checked the injectors?

Had a Camaro that showed no trouble codes but ran awfull after it warmed up. The injector coils had partially shorted.  Computer would send a pulse, and some injectors would give a partial shot.  It couldn't tell if each injector worked. Only if the cylinder bank gave a o2 feedback reading, which it did.  I finally made a resistance measurement on each injector coil and found 3 out of 8 were lower resistance. This after checking the fuel pressure rail for proper pressure.  Replacing the injectors totally cured the ailing motor.

Anyway, have you considered water droplets in the fuel? That certainly makes engines hiccup.

Just some ideas to consider.

Cheers,

[MikeSimon]

Don't know if you can determine whether it is an engine or a tranny issue.
If it is tranny, it could be a contamination issue in the hydraulic control body. Very sensitive to small particles getting in there and messing up control valve movements. Flushing could remedy this.

[Duke McDukiedook]

My wife's Acura would not throw a powertrain code with my normal OBDII scan tool or a CEL. I had to buy a Honda scan tool clone to find out exactly what the code was for her transmission range switch going out. I don't know what the Dodge specific scan tool system is but you should probably get one or get the dealer to scan it for you.

[dave500]

also often overlooked is the alternator ac voltage output,the recifiers can allow a tiny amount of ac through but it can become higher,the alternator will still charge fine but the ac can upset sensors and such,depending on electrical load like aircon on or off with headlights etc it can be hard to trace,check the output with your meter set to ac volts and see what you get?

[evinrude7]

i appreciate all the suggestions.  to recap i had the old trans fluid sucked out and then new put in last night.  17 qts.  i filled up with non-ethanol and dumped a big bottle of seafoam in the tank.  drove the truck all day without issue.  in fact it shifted buttery smooth even when i tried to goad it into acting up by feathering the gas right when it normally wants to shift.   

time will tell if the fluid flush was the fix.  i tend to think it's a number of things.  think i'll look for a high quality scanner that gives more detail than my 3 turns of the key and watch the codes on the digital odometer trick.  no CEL anyway so it's not going to throw a code. 

when i get some time i'll run through some of the suggestions you all made.  thanks much.   

[BobR]

posted this on the dodge ram forum.  thought why not post here.

2007 dodge ram 1500 hemi 5.7 4x4 w/545RFE trans.

been having a bucking/rough shifting/miss feel for about a year. NO CHECK ENGINE LIGHT.  it gets worse and i try one fix then it gets better for a while then gets worse and i try another fix. it's better then worse again. on a 10 mile trip it might do it 10 times. usually happens when i'm feathering the pedal just cruising along 45-65. did notice from 1st to 2nd gear this morning it had sort of a delayed shift once.

never slips. just a buck.

so far i've replaced the crank sensor, plugs (one of which was loose, far back one i may have forgotten to torque down on last change), throttle body taken off and cleaned, map sensor cleaned or replaced can't remember, trans service with filters.

these were all done after the truck began to act up. after the work it ran fine. months later it would act up again and i would try the next thing (as listed above) then it would be fine for months or i'd barely notice a little miss feeling once in months of driving.

spoke to a mechanic who said so you performed a trans service and it fixed the problem for a while then it came back? yes. so he said take it to a place that can completely suck the fluid out and replace. did that earlier this evening. bucked once on the way home.

any help appreciated. what's throwing me is there's no CEL. no codes to go by. which makes me think it's not a sensor.

thanks

  What you describe sounds like
a) torsional "buck" from a random misfire that is most noticeable when the transmissions torque converter is applied. (When the transmissions TC is applied its more like a manual as theres no fluid coupling cushion)  Anyway this is more likely at the speeds you describe "feathering the pedal just cruising along 45-65". Normally I'll hook up a scanner and see if the vehicle provides individual cylinder misfire counts. Very handy info though not always provided. Yes sometimes vehicles play dumb and dont throw a code especially if its not frequent enough.

b)an issue with the TCC (torque converter clutch) engagement. This also may be coming on and off "feathering the pedal just cruising along 45-65". Most TCC's are programed to release when you are off the throttle and ramp back on as you get back on the throttle  You didn't mention the mileage but at higher mileage it becomes suspect.   

Anyways this is speculation based on a transmission mechanics pov. without driving the vehicle. Bob

[evinrude7]

posted this on the dodge ram forum.  thought why not post here.

2007 dodge ram 1500 hemi 5.7 4x4 w/545RFE trans.

been having a bucking/rough shifting/miss feel for about a year. NO CHECK ENGINE LIGHT.  it gets worse and i try one fix then it gets better for a while then gets worse and i try another fix. it's better then worse again. on a 10 mile trip it might do it 10 times. usually happens when i'm feathering the pedal just cruising along 45-65. did notice from 1st to 2nd gear this morning it had sort of a delayed shift once.

never slips. just a buck.

so far i've replaced the crank sensor, plugs (one of which was loose, far back one i may have forgotten to torque down on last change), throttle body taken off and cleaned, map sensor cleaned or replaced can't remember, trans service with filters.

these were all done after the truck began to act up. after the work it ran fine. months later it would act up again and i would try the next thing (as listed above) then it would be fine for months or i'd barely notice a little miss feeling once in months of driving.

spoke to a mechanic who said so you performed a trans service and it fixed the problem for a while then it came back? yes. so he said take it to a place that can completely suck the fluid out and replace. did that earlier this evening. bucked once on the way home.

any help appreciated. what's throwing me is there's no CEL. no codes to go by. which makes me think it's not a sensor.

thanks

  What you describe sounds like
a) torsional "buck" from a random misfire that is most noticeable when the transmissions torque converter is applied. (When the transmissions TC is applied its more like a manual as theres no fluid coupling cushion)  Anyway this is more likely at the speeds you describe "feathering the pedal just cruising along 45-65". Normally I'll hook up a scanner and see if the vehicle provides individual cylinder misfire counts. Very handy info though not always provided. Yes sometimes vehicles play dumb and dont throw a code especially if its not frequent enough.

b)an issue with the TCC (torque converter clutch) engagement. This also may be coming on and off "feathering the pedal just cruising along 45-65". Most TCC's are programed to release when you are off the throttle and ramp back on as you get back on the throttle  You didn't mention the mileage but at higher mileage it becomes suspect.   

Anyways this is speculation based on a transmission mechanics pov. without driving the vehicle. Bob

well bob you've come to the right place being a transmission mechanic or rather i came to the right place.  sometimes it feels like a misfire.  sometimes it feels like a funky shift and slow enough that it doesn't feel like a misfire. 

last night i had the fluid completely pulled from the trans and new put in.  one buck last night on the way home.  drove it all day and it was smooth. 

mileage is 123k.  i keep up on the maintenance fairly well.  don't do a ton of hauling besides the short bed full of work site debris.  usually old 2X material.  previous owner pulled a small rv trailer as it has an aftermarket trailer brake system installed.  i got it from him when it had 50k miles.  it has the tow haul button on it for hauling heavy loads. 

[BobR]

The 545RFE trans has issues with valves bores in the pump wearing too. Hooefully thats not the case. Every tranny out there has its weak areas.
   You have been kind to your vehicle and that helps. At any rate hooe you get it sorted out. Let us know what you find. Also google is helpful- the collective experience of thousands of owners can be useful if sifted thru carefully . HTH Bob

[evinrude7]

thanks bob

[Duke McDukiedook]

Like I said and Bob said your ecu or the transmission computer could be throwing codes without tripping a CEL. When you get a manufacturer specific scanner or clone you can monitor the vehicle in real-time as it runs to see if it throws temporary error codes that don't trip a CEL.

[BobR]

thanks bob

You are most welcome. Unfortunately I can only offer is speculation based on experience from a distance. As mentioned a scanner monitoring data (in the right hands) is your best bet though intermittant problems especially ones not throwing codes can be difficult. Bob

[71NOVADUDE]

change out the pickup coil. it does not throw a code. had same problem changed pickup coil and problem went away.

[evinrude7]

change out the pickup coil. it does not throw a code. had same problem changed pickup coil and problem went away.

what's a pickup coil?  the individual cylinders have coil packs.  is it like a master? 

[my name is nobody]

Been a while for me, out of the field of automotive, but "mode 6" data might help(?) if you have the scanner that supports it.

I used to use that mode to find intermittent misfires that had occurred previously and couldn't be found elsewhere or otherwise.

[my name is nobody]

change out the pickup coil. it does not throw a code. had same problem changed pickup coil and problem went away.

what's a pickup coil?  the individual cylinders have coil packs.  is it like a master?

Your crank sensor takes its place I believe....

[evinrude7]

change out the pickup coil. it does not throw a code. had same problem changed pickup coil and problem went away.

what's a pickup coil?  the individual cylinders have coil packs.  is it like a master?

Your crank sensor takes its place I believe....

think i changed that out last year.

[evinrude7]

The 545RFE trans has issues with valves bores in the pump wearing too. Hooefully thats not the case. Every tranny out there has its weak areas.
   You have been kind to your vehicle and that helps. At any rate hooe you get it sorted out. Let us know what you find. Also google is helpful- the collective experience of thousands of owners can be useful if sifted thru carefully . HTH Bob

ran the truck in tow haul mode today.  no shifting issues, bucking or hesitations.  yesterday i felt it twice in regular mode with overdrive.

[ekpent]

 My 2002 Ford F250 was bucking in overdrive and throwing no codes etc.. I was getting pretty convinced that I might have a bad coil pack or two but bought some spark plugs and my neighbor who is a professional mechanic at a dealership put them in which is no easy chore on these. Fixed the problem and runs/rides great. We both chuckled at was was left of the original plugs firing points and the lesson for me was 120,000 miles is about it for stock plugs ! 

[evinrude7]

My 2002 Ford F250 was bucking in overdrive and throwing no codes etc.. I was getting pretty convinced that I might have a bad coil pack or two but bought some spark plugs and my neighbor who is a professional mechanic at a dealership put them in which is no easy chore on these. Fixed the problem and runs/rides great. We both chuckled at was was left of the original plugs firing points and the lesson for me was 120,000 miles is about it for stock plugs ! 

i've changed the plugs twice since i've had the truck and put 70K on the clock.  last change was this summer.  that service fixed the last time it was doing this.  i might pull them out again and get a look.  thanks eric.  yep the back two cylinders are a #$%*.  plus my truck has two plugs per cylinder. 

[ekpent]

My 2002 Ford F250 was bucking in overdrive and throwing no codes etc.. I was getting pretty convinced that I might have a bad coil pack or two but bought some spark plugs and my neighbor who is a professional mechanic at a dealership put them in which is no easy chore on these. Fixed the problem and runs/rides great. We both chuckled at was was left of the original plugs firing points and the lesson for me was 120,000 miles is about it for stock plugs ! 

i've changed the plugs twice since i've had the truck and put 70K on the clock.  last change was this summer.  that service fixed the last time it was doing this.  i might pull them out again and get a look.  thanks eric.  yep the back two cylinders are a #$%*.  plus my truck has two plugs per cylinder. 

Double your pleasure-Double your fun !!