Rough idle and fluctuations

alright so i tested the ignition coils following this FSM
and at 88* F I got 1.1-1.2 all around for step 3, and I ~13 on step 5

 

Ended up taking it into the dealer since ive been chasing this for a year. They had it for 2 days and ran every kind of test, fuel, compression, cleaned everything, reset motor mounts, transmission mount check. And they couldnt find anything 'wrong'... Unsure what to do next.

 

final update... ended up being the transmission mount. Since it was bad when i first replaced it (rubber completely disconnected) it was causing this. I replaced it with the "upgraded" one from 4x innovations but it made the rumble sooo much worse it was unbearable at idle. Ended up swapping to one that oreillys had and its calm and a pleasure to drive once again.

I fell victim to the "oh it couldnt possibly be that since its new"...
So in my experience the 4x innovations transmission mount isnt worth it unless youre willing to deal with that rumble and your doing a strictly 4x4 build. For a daily driver I couldnt tolerate it.

 

That's funny because I had a small rhythmic vibration (only detectable at idle) that was clearly coming from the engine. You could feel it with your hand on the intake plenum, steering wheel, shifter knob, or center armrest. I replaced my old OEM trans mount with the 4xinnovations one, and the vibration went away. The whole truck does now rumble (like you described), but it doesn't really bother me.

 

@Red_03Taco Interesting! it probably wouldnt bother me as much if it didnt aggressively accentuate the door and dash rattles.

 

I totally understand that. I just love the way it feels when you give her the beans. Always felt that the drivetrain didn't feel really connected to the truck (kinda sloppy during hard acceleration), until I upgraded to the 4xinnovations trans mount. But yeah that thing doesn't make the truck feel very refined lol

 

I think ill keep it on the shelf for now and once i have a reason to get into the dash, fix rattles then try again. Doing door rattles this weekend when adding my sound deadening and new speakers.
Good to know others find it tolerable. hopefully its just that, or maby im just being a b**** . Glad to have figured it out either way. Its so much better knowing than thinking something was wrong and that I was slowly adding damage by driving it daily...

 

Yea these things are tanks, ain't no rattles gonna hurt them. The rattles would hurt the driver before the truck lol. My friend hates driving my truck (and he's got a couple 1st gens), because he too hates the aggressive rumbling from that trans mount

 

Holy crap! This is driving me crazy with all of the same things happening. I got a new OBDII scanner and it doesn’t seem to read live for anything other then battery volts. Dealing with trying to shuffle through this PDF Service Manual with hella files. Hahaha I’m dead!

 

Did you end up checking the transmission mount? That ended up being my issue. You can disconnect the trans from the cross member, 4 12mm bolts i believe, and use a jack to lift it.
Just lift it off the cross member barely enough to take the weight off and have it not touching. Start engine, see if rough idle continues to rule this out

 

Yea it’s jacked. I’m not getting any codes. Runs fine for about 5 mins and then a low pulsing idle. Do you know what that is called? It’s the crankcase ventilation hose no 2 on the driver side. It’s a hollow 90° tube that’s connects to the hose running to air intake. I’m about to pull it right off and it's leaking like mf. Is it’s supposed to be a different PVC connector there? I don’t know what it’s called to find something that works. It won’t fit if there’s a grommet in place. Is there an aftermarket or oem part# you can refer me too? I attached some photos to help explain what I’m asking. Thank you.

 

I have so far done the following:
- Spark plugs & Wires
- Replaced vacuum hoses and need a better test. Actually need to replace hoses at the rear canister still.
- Cleaned the throttle body/IAC replacing both gasket
- MAF cleaned
- PCV Valve and tube also brand new
- Checked resistance to coil packs, vcv, vsv, iac, throttle and it’s all good.

sparkplug cylinder gaskets leaking a bit, and the half moons as well. But it’s never made anything like this until I changed the spark wires.

 

From the looks of this you need a new valve cover? I dont believe that elbow is suppose to come off like that.
( im guessing, so maybe someone has seen this before and can correct )

When I lookup replacement driver side valve covers, they all have that elbow attached.
I cant seem to locate a distinct part number for just the elbow as I think its all one piece (or should be?)

 

Get some green Loctite on that, and press it back in there like it never happened.

 

Bro, I feel like an idiot not thinking about looking up a whole as* valve cover. I’ve spent days researching and parts shop didnt know either besides asking if it’s a 2wd or 4wd. Thank you

should be

That’s genius. Thank you. I had to figure fitting before I started doing anything. This other port on the L, below the headers…do I have anything to worry about? Anyone feel free to chime in….Ive never noticed until the other day.

 

I read the title and saw all the posts (at work, not reading the entire thread), but I had a rough idle issue before like OP was experiencing. For me, this issue was caused by a dirty throttle body. I removed it completely, cleaned it, and reinstalled it. The idle runs smoothly. I hope this will be helpful to someone else in the future.

 

If you mean this (i just zoomed in )


this is just a coolant drain to get coolant out of the block.
So its fine. When you want to drain coolant from the block you can just attach a hose and the bolt above it opens/closes it.
I know this bad boy all too well when it took ~15 flushes to get the crappy green coolant and rust from my system lol

 

Does green loctite hold up to heat very well? Never used
@ChargedSHOTaco

 

On a valve cover, it wouldn’t be a problem.

 

Cool. I’ve never seen an issue but wanted to ask. A flush is in the works too.