rough idle 124000 1500 5.7

[ian bressette]

i have 2012 dodge ram 1500 big horn 5.7 hemi. brought used and not under warranty since i brought bit of rough idle it performs well replaced spark plugs no codes or any problems and clean throttle body. but still feel it what else could cause I'm doing a full fluid flush through out truck only have 124000 km and i have had this since i brought or replaced spark plugs. Running reg gas and synthetic oil. Anyone else???

 

[crackerjack1957]

Try running a few tanks of 90-93 non-ethanol with some fuel injector cleaner like Redline SL-1 or equivalent.
Also check air filter & pcv valve.

 

[Casper]

Seafoam. If you don't have a catch can, all the oil and yiltch from the PCV has been pumping into your intake manifold for 124K miles and been exposed to operating temperatures. These are not direct injected engines, but injector cleaner alone wont clean the whole intake.

If you buy the can with the lil red straw, you can shoot it right down the TB. You'll need an assistant to keep rpms up however.

 

[molollar]

Install a vacuum gauge and make sure it’s not fluttering around at idle, these motors can be bad for camshafts wearing on the mds cylinders, best to rule it out and a vacuum gauge will show that


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[crackerjack1957]

That was 124000 km so that's a little over 77k in miles.
When you cleaned throttle body if it was not that bad, intake & valves probably not cause of rough idle but Seafoam is good.
Hopefully not the cam/liffter issue......not good.

You saying it performs well at WOT?
Seem to remember this happened to someone else & they did the same maintenance you did & it ended up with new pcv valve solving theirs.
They are on the expensive side though......$50 maybe.

Here is the post that had pcv valve issue.
He said he paid $25 but mine was $49.94 shipped with tax.
Maybe he purchased aftermarket, I got Mopar #53032940AB (2011-2016 Ram 1500)
https://www.ramforum.com/posts/1940452/

 

[Doodoo972]

Hy Ian, I have exactly the same thing on my truck. It's a 2012 too. I' ve changed the sparkplug, the pcv valve, cleaned the throttle body but it was allways present. It seemed to be a little better when I had some additive in the fuel tank. I' m running on 91.
I will add some injector cleaner and I'll see...