Need some advice. My 05 2500 has always idled at a rock-steady 750 rpms. Just recently, after some outside temps that reached down in the teens, I have noticed a slight miss in the engine. It is such a small miss I was thinking about just ignoring it, but it's new and I can detect it.

I don't think it happens when driving, if it does I can't feel it. The fuel filter has less than 3K on it. Could it be a dirty injector, or moisture in the fuel, or maybe that wire under the oil filter(causing a quick short) that I have read about on here?

I have only run one bottle of additive(can't recall the brand) through the tank, and that was about 9 months ago. What would be a good choice to clean the injectors?

Any and all feedback is appreciated.
Chris

 

Do you feel it, or hear it?

 

Both. Again, I am listening for it now because it bugs me, but I can hear it, feel it, and see it twitch the tach.

 

Get some Howe's at an O'Riley's. it is good stuff. It'll smooth it out. I don't drive mine as much and noticed a slight miss just like you said and Howe's did the job and I get about 1.5 mpg better after 2 doses.

 

I had occasional rought idle problems about 15K ago. Took it to a local diesel shop and he suggested running 5gal of bio-diesel that he sold (his blend with tight contol on spec). He said the solvant characteristics of bio will sometimes dissolve deposits that form on injectors. I did this and also started using RedLine diesel catalyst conditioner at 1.5 recommended strength at alternate fill-ups. BTW, I called RL and spoke with their engineer, they said this would be OK. Anyway, that was 15 to 20K ago and it's been running great. Still use RL at recommended blend.

 

Are you positive its not related to grid heater, a/c compressor cycling, etc? Those place a demand on the engine that is easier to see/hear/feel when the air and motor are cold.

I do think a good additive and a good tow can really help any injector issues, if you have some.

 

Thanks to all.
I probably will run some Howe's through it, can't hurt. However, there is a chance it could be the cold air/engine. It was real cold when I first saw it, about 19 degrees F, and was cold soaked for 4 days. I felt it drop a tad as it switched B/N low and high idle, and the electrics (dash lights)twitched as well, but that is normal. But since then it has warmed into the 40's and I still see/hear/feel it.

Even in a steady low idle, I know the heater/air system has it's own cycles that it does, and that does affect the rpms. Again, this seems different. I have 58K on it and it has never made me second guess until know. I ride jet engines for a living, so I am kind of geared to listen and feel for stuff that doesn't seem normal.

Thanks again to all who have responded. Has anyone had that wire under the oil filter problem that I have read about??

 

you can try pulling out the injectors and cleaning out the holes and injectors , thats what worked for me

 

"you can try pulling out the injectors and cleaning out the holes and injectors , thats what worked for me"


Why? It takes $10 and three seconds to pour some Howes in the tank. My rough idle cleared up about 10 miles down the road with it in there.

 

I don't know....I have this intermittently with mine and I have been using Howe's MeanerKleaner for a couple of months. It seems more prevalent in colder weater (colder here in SoCal means 40s-50s) but I have experienced it even with a warm engine restarting after being off for a short time. For me, the feeling is as if one cylinder is not firing at all or is misfiring. Every time, the problem goes away within a block or so of normal driving.

Is there a way to easily test the injectors? I only have about 56k on my truck but the 7 years is due to expire in April. If I have injectors on the brink of failure, I'd like to get them replaced while it's still covered.

 

oh because the additive didnt work for me

 

I had the same problem. A slight miss sound, so I tried running 2 cycle oil and it was the trick for me. motor runs smooth as silk now. My current fuel procedure is 3 tanks oil to 1 tank seafoam. Seem to work well. It might be the winter blend of fuel.

 

My '05 does that too when the temps drop. Does it still do it after the motor is all warmed up ?Try manually setting the high idle, mine completely stops when I bump it up. I think it is the draw from the grid heater.

I have also run 12 to 14ozs 2 stroke with good results. Some use a whole quart, but my trucks likes a little less. I was suprised how quiet and smooth it runs. No noticible change if mpg.

 

Seafoam contains alcohol, which makes water almost impossible to separate and can do much more harm than good.