Hey yall I've never posted anything on any forum before so be please patient with me because I don't know all the rules and procedures. With that said-- I have a 2004.5 HO Cummins, with a 6 speed if it matters, and I have recently noticed my valves making more noise than normal. I had them adjusted and it helped a little and the mechanic told me if I absolutely couldn't live with what noise was left he would go deeper. I was cool with it until this past weekend when it started getting louder again and my exhaust started getting louder and more obnoxious (high gear around 2500-3000RPM). The sound of a straight-piped Cummins is like the song of angels to me- I LOVE IT- but it suddenly sounds like a V-8 with glass packs or even--choke--a straight-piped POWERSTROKE. It also seems to have a small, barely noticable vibration that corresponds with the hammering exhaust sound. AND although I know the overhead MPG display isn't close to correct, it has dropped about 2 MPG from where it normally resides. The Exhaust sound is the main concern because I know it can point to bad problems. In the year I've owned it this thing has never really sounded like ANY Cummins i've ever heard and now it sounds like something is really wrong. No noticable performance loss, no programmer or injectors or anything (yet). Just an upgraded airbox and a tiny amount of suspension lift. Any ideas guys? HELLLLLLP ! Thanks for any and all input.

 

Check your oil to see if it is (over full) or making oil...sounds like a bad injector or injectors...When they go they can pump fuel into the cylinders filling the crankcase with fuel and destroying the oil.

 

Definitely check your oil level. Also what does the exhaust color look like? Do you get any white exhaust at startup? Not just a little but a good amount. Do you have a prolonged crank time?


Just curious. What part of TN are you in, I'm at the VA/TN border.

 

If your oil level is looking good, try running some injector cleaner and hook up a trailer and run it through the hills. Might just be carbon build up on the tips. Mine always seems to run better/quieter after a trip with a load.

 

^^^^^check above...but also have you ran it HOT lately??? I mean high EGT's??? sounds also like a dropped or dropping exhaust valve seat.

 

dropped valve is really loud and makes a knocking noise been their done that. i would lean towards injector issues

 

If all your fluids and filters are good...

Like said, take it for a good workout, and see what happens...sometimes that's all it needs.

Or something will break, and then you'll know what to fix...

 

All these guys who posted cover about everything that could be the issue. I would try some power service or some 2 cycle oil, I know that my truck runs smoother on the 2 cycle mix. I think you have injector problem, and sure hope its not a valve.

 

I checked my oil level and is looks fine and doesn't smell like fuel. It doesn't smoke on startup and has no cranking issues. It DOES however smoke a little more when i put my foot in it lately but I haven't noticed any white smoke. I haven't ran it hot at all and haven't really pulled it hard at all (yet). I dumped some Lucas Injector Cleaner in the tank yesterday and it seems like it MIGHT be helping a tiny bit but its not cured. I'm gonna try a different fuel source when I finish this tank and I'll change my filter this weekend and take it for a loaded stroll through the mountains. Is there a fuel pre-filter on these things? I heard it had 2 fuel filters but I haven't really had a chance to look yet. Thank you all for the advice. I'll let yall know what I come up with

 

I have exactly the same problem with my 06. I now run Diesel Power Service in every tank. Makes a huge difference. I use the grey bottles not the white or red. I've tried lucas and a few others but nothing works as well as the power service.

 

There should only be one fuel filter. In the factory canister located in the engine bay. If the truck had a previous owner they could have added extra filtration, or if the lift pump was replaced, some replacement types came with an inline strainer to be installed right before the pump. ( you would be able to see this on the inside of frame rail just behind drivers front wheel.) I also run power service (grey bottle). The way I understand it is the only difference in the grey and white bottles is the white has an additive to prevent gelling.
Check the air filter also, restriction will also cause smoke. (you've probably already done this)

 

OK so it was determined that I needed new injectors because 4 of mine were supposedly cracked. Now, a week and 2300.00 later I'm back on the road and now I'm missing about 40 horses under the hood and about 10 miles per gallon. I'm gonna change my fuel filter today in hopes of some kind of improvement. Could a clogged fuel filter cause THIS extreme of a change? Guess i'll find out when I get off work. Thanks

 

Something is not right. Checked the oil level? They could botched the installation and damaged the connector tubes or injectors, or missing copper sealing washers.

MikeyB

 

if going to run Power Service definitely use Gray bottle- Cetane Boost is the trade name i believe. White bottle is to lower CFPP- red is only to un-gel filter- if truck gels- pour into filter