so.


2012 ram 4x4 quad cab slt 4.7.

25k miles.

This is the problem. it has an intermitent lack of *****.
i realize its a 4.7. BUT one day i filled it up and all of a sudden it had no power. barely can push it past 80 unless i try really hard. if i decel then accel it doesnt want to go, i have to almost floor board it and it downshifts and goes. NOW. i have noticed the following.

when its cold outside it seems to run better, when hot worse.

also maybe just my imagination but i swear to you when i have under an 1/8 of a tank it runs like it should, plenty of power, no hesitation etc.

fill it up again, and again we are back to the bogging, hesitation etc...

it is also surging rpms at 40-45 mph when trying to maintain that speed.

took it to dealer four times. first and second time they said they couldnt do anything cause there is no CEL.

third time, nothing wrong they said.

fourth time, they tell me its running "like a 4.7" and its lagging cause i hve 33 inch tires and 20's vs the 17s. <-----BS!

basically they cant diag it cause they dont care to.

i have tried replacing the tps, no help, MAP no help, IAT no help. checked plugs, wires, etc.. all look good.

not a vacuum leak, checked evap canister, checked the numbers wit my solus scanner at work and no lean or rich condition as far as i can tell at idle.

idles fine, WOT seems ok... it only appears to happen in midrange.


soooo this leads me to my question, sorry about the long windedness.

im thinking the fuel tank vent line/filter may be clogged cause a build up of excess pressure in the tank and or not letting enough air in to maintain fuel volume.

THOUGHTS????!?!!??!?!?!?

 

All I can say is...

I "had" a 4.7 '05 Ram 1500, and mid-range power sucked! I know the newer version had a bit more ponies, but this is also why I've owned three Hemi's since then.

 

i dont expec it to be a race truck and this is sucky mid range power. this is under mid throttle after decel it takes 15 seconds to get from 25 to 45 mph

 

and the 2012 4.7 has as much hp as the older hemi's. its plenty of motor, something is just not right

 

and did i mention im getting 12 mpg highway and 8 city???

 

If you can't get any satisfaction from your dealer take it to another one and go on the test run with them.

 

If you can rev up the truck in park or N and it revs than I suspect the transmison is not is not talking with the coumputer disconect booth batt cables and reconect after 15.in ti restet the coumputer.

 

im confused about your post cyclone. of course it revs in park and nuetral...

and as far as taking it to another dealer it was at one the first two times at another the second two.

i called chryser and got them involved but they arent much help. and there is no cel.

this is my first ram truck ever and i decided that if they cant fix it the next time, i take it in, im trading it in and i will never buy another dodge. other trucks dont have half the problems these trucks do.

 

Just a suggestion, although this would likely throw a CEL, check your throttle body, make site the blade is retracking completely (manually moving the blade). Even test it in "park" and have another individual give it some throttle to see out the blade reacts.

I've seen this happen on a 2007 Chrysler 300C.

8\12 mpg's are rediculous numbers for a 4.7, they should be comparable to the 5.7.

 

Good idea. Get rid of it. All dodges are the same.