Engine smokes and rough Idle on start up
 

I have a 2007 ram3500 w/5.9 and 6spd trans with 131000 miles on it. I bought the trk used and for the last couple weeks when the engine is cold and cranked up for the first time, it smokes and runs rough, and it smells like diesel when doing so. when the trk gets warmed up it quits. any ideas on what to look for.

i would do a compression test, min spec is 350psi but an engine in good shape will be around 500psi, if it has a broken ring then its going to be at 150psi or less on that cylinder

if the test shows all good then since you would have the injectors out at that point i would have them flow tested

thanks for the info. I hope not a broken ring, injector would be bad enough. any Idea what the cost would be to do rings on one of these.

Injector time!

1 piston 6 ring sets 12 rod bearings (all genuine cummins parts) and labor +- $1800 as long as it hasnt got into the block enough to require machine work

do you think it could be a broke ring. I think it would smoke continously if it had a broken ring. if it were a injector going out, should I replace all or just the bad. can i check to see if a injector is the problem at hm myself?

injectors there prob over fueling

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its better to replace all 6 and no you will need to take it to a shop

what about: glow plugs and grid heater?

it dosnt have glow plugs

we have had more then one truck that has came in with a similar problem and they all cleared up after the engine was up to operating temp, they would white smoke on start up but as engine temp would rise they would run better and at operating temp they cleared up

it could also be an injector thats overfueling i was just saying that if your going to pull the injectors out i'd run a compressoin test while they are out, it has become standard practice for our shop, only takes about 30min and we dont charge for it, gives the customer peace of mind if they all come back good and if a problem cylinder is caught early enough it can be fixed with the block in the frame

also if i did happen to fail the compression test you would still need to have the injectors tested because an overfueling injector can cause higher cylinder temp in that cylinder and result in the broken ring, so you dont want to fix the symptom and not fix the cause if ya know what i mean

yah, Cummins is not my strong point. sounds like you guys have it under control