Ruff idle?

[MKenison]

Once in a while, my truck has a ruff idle. Mostly in drive, but I also notice it in the morning in park. Should I worry about this?

 

[JFaughn]

Is it all the warm ,cold , then more info , fill in truck info at user control pannel ,yr. mod. ect. maintance things 1st fuel filter, valve adjustment, more info more answers later.

 

[MKenison]

mostly cold. Its a 04, 40k miles, SO cali truck. have changed the fuel filter once, no valve adjust yet. How many miles for a value adjust?

 

[JFaughn]

I think factory says every 30,000 miles, but a lot of guys after getting familier sith there trucks are saying that they do much longer, the reason I mentioned it is becouse the valves getting out of adjustment , one of the symptoms is a ruff idle , and the way I work in my shop is cover all the maintance 1st then stick with the basics and after those diagnostics before parts [ some times on the computorised stuff the manual will say replace with known good part and retest] , Have you used any of the fuel treatments ,cleaners , also inbetween fuel filter changes open the water drain on bottom of filter and catch with clear container , let settle and see if any thing besides fuel is there , if so change filter and add diesel fuel injection cleaner , theres a lot of ??? fuel , so be your own best defence , if you've been reading here much you would notice that with the newer truck it is especialy important to have a fuel gauge becouse of the weak fuel systems , the lift pump goes then that takes out the main pump [ big bucks ] with a gauge you can see the pressure go down and get the lift pump before the main , some guys are having a lot of problums getting it covered under warentee, next torwards the complicated stuff , is have dealer or do it yourself parts house [ free ] check for codes , with a truck that new chase the dealer . Let us know what happens .

 

[mberry]

I think factory says every 30,000 miles, but a lot of guys after getting familier sith there trucks are saying that they do much longer, the reason I mentioned it is becouse the valves getting out of adjustment , one of the symptoms is a ruff idle , and the way I work in my shop is cover all the maintance 1st then stick with the basics and after those diagnostics before parts [ some times on the computorised stuff the manual will say replace with known good part and retest] , Have you used any of the fuel treatments ,cleaners , also inbetween fuel filter changes open the water drain on bottom of filter and catch with clear container , let settle and see if any thing besides fuel is there , if so change filter and add diesel fuel injection cleaner , theres a lot of ??? fuel , so be your own best defence , if you've been reading here much you would notice that with the newer truck it is especialy important to have a fuel gauge becouse of the weak fuel systems , the lift pump goes then that takes out the main pump [ big bucks ] with a gauge you can see the pressure go down and get the lift pump before the main , some guys are having a lot of problums getting it covered under warentee, next torwards the complicated stuff , is have dealer or do it yourself parts house [ free ] check for codes , with a truck that new chase the dealer . Let us know what happens .

I do not mean to be contradictory, just trying to give accurate information.





1st valve adjustment is at 100K miles for 3rd gen's. Fuel injector cleaner will help the rough idle, but the 3rd gens have reported a lot of rough idle trucks when cold, mine included.



The 3rd Gen CR diesel will just flat die if the lift pump fails since the CP3 pump cannot pump enough fuel itself to run like the VP44 trucks could. A fuel pressure guage should be put on for monitoring purposes and most often will give you indications before the LP fails completely. Fuel filters are supposed to be changed every 15K miles I believe, so that could be part of the issue also.



You can get most of the codes yourself through the odometer display.



If I am wrong on anything please correct me. Hope this helps. Thanks.

 

[DPKetchum]

Actually valve adjust is at 130k hard usage and 150k LITE usage. But 100k sounds fine. LOL

 

[ilovetrains]

must be real dog - ruff ruff!