I will try to be as thorough as possible so yall don't have to ask me a million questions. Ok so here goes...

First off the video:

https://www.youtube.com/watch?v=MwHv...ature=youtu.be

I've only had the truck for 7 months and I have no idea of it's history. It has a slight lope? miss maybe? on the first start of the day until its warmed up. It gets a bit worse when the high idle kicks on but that feature seems to have a mind of its own. Sometimes it comes on sometimes it doesn't no matter the temperature. Just this afternoon when I park and put the truck in park it came on out of nowhere. The symptoms seem to go away when I put my foot on the accelerator even if i rev it myself to 1100 which is the same as the high idle it is smooth as can be. The truck is a 2003 2500 Regular Cab 4x4 High Output Vin C it just his 210k. It has CAI, GDP MK2 with CAT 2 mic filter, Baldwin 5 mic in canister, and Bullydog Torque Dog pressure box. I service every 5k with Rotella T 15w-40, K&N oil filter, and canister fuel filter. CAT filter every other service. The oil stays about as clean as it came out of the jug until close to service time. I recently checked the valve lash (no adjustments made) and re-torqued the crossover tubes to 37ft/lbs. 1-5 were good they may have tightened just a bit. 6 was fairly loose. I've checked the temps at the exhaust manifold with an IR thermometer all are within 5-8 degrees of each other and I've also done the cut-off test the injectors appear to be fine. No smoke...none. Whenever the fuel bowl is drained and the truck started it runs smooth and doesn't do anything which I find bizarre. No loss in power, economy is fine also. I don't run any additives and I also replaced the FCA. I've been driving like this for some time with no issues but something about it just doesn't sound right. The video doesn't do it much justice but it gives you an idea. I apologize for how scatter brained this post is I was just trying to include everything. Thanks for any advice! Cheers!

 

my 2004 does the exact same thing with 121,000 miles on it. cant seem to find any answers.

 

mine does this as well, i have tested everything and came up with turbo chatter, that is the only thing I could possibly see having anything to do with it, when I listen to engine when it does it, there is no change in sound or rpm.......

 

The turbo is not even a factor at idle.

The very FIRST thing to do with symptoms like this is run SeaFoam or your favorite cleaner thru the system. Drain the filter housing and fill with injector cleaner then run it for 30-60 seconds to push the cleaner into the system and injectors. Shut it off and let it sit overnight at least.

Get you favorite additive and dose the tank heavy with a quart of it and fill with clean fuel. Then all you can do is drive it as hard a spossible and get the engine to operating temp for as long as possible.

More and more this is coming up as the ULSD shows it unique traits over time. A lkot of these problems can be traced directyl to the asphaltenes being cooked out of the fuel and causing build up in the fuel system. An additve that both conditions and cleans the fuel is MANDATORY. Most additives contain adequate solvents to do the job, Power Service has done me very well ofver the years. FleetGuard has a formulation specifically for ULSD and the asphaltene problems.

Additives are a good thing despite all the nay-sayers. Too many differences in fuel and usage to for a blanket statement like that. An additive package will NOT hurt a thing, it can do nothing but help.

 

When you say that a turbo has no affect at idle you are correct but misunderstood my meaning, next time I’ll make sure I’m more technical.

the job of a turbo is like a air pump, but it also creates back pressure because the engine has to work a little harder to push the air out, HENCE if you have a larger turbo and there is no pressure being built it can cause choppy air because both sides of the turbo are not at equal pressure causing the exhaust to sound choppy, he has stated that he replaced the FCA, he could have received a bad one from the start, if you still have issues and only if the rpm’s are showing a difference, then I would do a test on the injectors, see if you have an injector that is sticking open and the only reason why you are feeling this at idle because it is an injector that is slightly opened when at idle and then when you are pressing the pedal for more fuel, that injector or injectors are functioning properly at higher rpm levels, in some cases it could also be your lift pump and your injection pump is going out, when your injection pump is weak and at idle it can show symptoms of choppy and irregular idle caused because the pump is not able to pull enough fuel to keep the engine running smooth, when this happens, the FCA tries to accommodate for the missing fuel which in turn will give the same symptoms

What I was trying to explain, I have an aftermarket turbo on mine, when my truck is at idle, I do here changes in the exhaust , not the engine (engine shows no change at all, just exhaust) I also had it hooked to EFI LIVE to check all parameters, no difference in engine at all

I would not recommend using sea foam in a diesel engine (not saying that some people have, I just would never use in any of my engines, I care too much about them)