i am fairly new to cummins and diesel engines, i get about 12 MPG arround town and freeway. i bought the truck about 4 months ago and the owner never mentioned anything about the last time he adjusted the valves, a freind said it sounded like they needed to be done. just wondering but, if the valves havent been touched in a while would that cause fuel mileage to suffer?

also, i recently discovered a boost leak, i know this can have an effect on fuel mileage as well, however it never leaked when i bought the truck and now that it is leaking, fuel mileage hasnt changed. it is leaking out of the joint where the turbo and the aluminum elbow connect(intercooled). i pulled the clamp off and found that the flat o-ring was cracked. so thats where its leaking from but does anyone know where i can find this o-ring. i went to the dealership and they said dodge discontinued that part #. so i went to lowes, home depot, ace, auto zone, kragen and osh. no one had it. any ideas?

 

That o-ring failing is fairly common. You just need to get to a dealer that has those sorts of parts.
I know PDR has them, or if not they can get them I would think.
I'm not certain if you need to go to a Cummins dealer or a Holset dealer to get that thing.

pb....

 

Your Dodge dealer is pulling your leg. The oring is steal offered by dodge,and pdr dose have them. Your vales being out off adjustment,can make your fuel mileage drop. I adjust my vales ever 10,000 miles cummins says every 20,000. Check your vales! Your Egt's will also be higher and your engine will be under powered, and start harded when the vale's are out of adjustment.

 

Just replaced mine a month ago. Got it from Cummins dealer. They are yellow now. Price: $18.00 bucks!!! Crazy, huh?! I'd hate to think what a Dodge dealer would want-buying straight thru Cummins has always been cheaper for me. Carmyne

 

How complicated a process is valve adjustment on these engines? I would like to adjust the valves on mine (and have on a range of vehicles from BMW motorcycles to Landcruisers), but I don't want to have to buy a bunch of factory tools to do it.
Got a Case VAC, too...
- Chris

 

The only tool that is somewhat uncommon to adjust the valves is a feeler gauge and you can easily get one from a parts place for $10

 

i imagine it is easy, just time consuming. thanks for the help guys i will locate the cummins dealer and get that o ring, then adjust the valves and see what happens. by the way my egts get pretty high and get there fast.

 

Got that-- I was thinking of stuff like TDC locating tools, or the paraphernalia needed for a shim-&-bucket valve adjustment. Thanks for the info!
- Chris

 

You can use the timing pin which is located under the injection pump to get it at TDC

 

It's already there, or that's where it goes after I get one?
- Chris

 

its already there from factory