Running warm, Low power, Bad mileage - Sick Truck!

[DBabbitt]

2004. 5 Dually QC 2wd CTD automatic w/4. 10 rears. Towing a trailer cross country. Started noticing power loss a few days ago and bad mileage at the same time. Now it's running warm under load (about 225 deg. ) 1/2 way between 200 & top of the operating range. It quickly cools back down when coasting or going down hill. truck has 85k miles on it. All filters are new, Fuel, air, oil. All fluids are fresh. trailer is a 3 car 48' wedge. been running about 25. 5k combined total weight. getting 7. 5 mpg on hills of & 8. 5 mpg on flat land. Have filled tank several times from Florida to New Mexico with no change. Truck usually gets 10. 5-12 mpg under same conditions and ALWAYS runs at a stable 195-200 deg. Took it to the dealer today. They can't find anything wrong. Guess it needs a heavy load to run bad! The power feels fine and the mpg is fine w/o the trailer. It will get a bit warm (210) going up hills. Dealer says that's normal but I bought this truck new and I've never seen it go above 200 till now plus it was only 52 deg. today in Denver.

Anybody had similar problems?

 

[GWBourne]

i have 36k on mine and pull 22klbs and NEVER have any issues... i am guessing no engine codes have come up because of your very in depth description. stock truck otherwise i assume as well... ? cycle the key three times and see if something comes up is all i can think...



bad fuel maybe, but since you fill up so much then you would have had to take the SAME route as the tanker and i just dont see that happening... .

Grant

 

[AMink]

The low power and poor mileage could be caused by a tiny leak in the intake hoses from the turbo to the intercooler or IC to intake. I don't know if that would cause higher temps though. Do you have an EGT gauge? If that is up too, I'd start looking for a leak in the hose or IC. Good luck! Maybe one of the guys more familiar with the electronics stuff will chime in. Might put thread in the 2nd gen 24v section for more coverage.

 

[jelag]

I tow a trailer that weighs 20K... . my 04 dually now has 185K miles..... its never seen a full tank of fuel empty..... the temp gauge runs between the 2 and first zero when empty..... it moves to split the first zero when loaded and running flat out across the desert in a 110* day..... and moves to the center or just on the edge of the second zero when pulling the grape vine going into LA or coming back acoss the divide in ID and MT on I-15 and I-90.....



The loose intake system mentioned above could cause part of the problem..... I had some work done to this truck and the body shop... . had the intercooler off... . the truck ran fine empty... . but had a lack of power loaded... we found a clamp loose and as soon as we tightened it back up, things got back to normal..... OTOH it could mean other problems as well... .

 

[DBabbitt]

I checked the clamps for the turbo hoses and nothing is loose or cant see any problem with the hoses. The truck is completely stock with no gauges of any sort (stupid I know. ) I called a friend who used to be a service manager at a Dodge dealer in GA. He told me it sounds like the fuel limiter valve. I am waiting for the mechanic who looked at my truck yesterday to call me back so I can ask him if he checked that and what the psi readings were. Don't you just love it when you take your vehicle to the dealer and they can't find anything wrong so they treat you like you're crazy?



Thanks, Dan.

 

[AMink]

IIRC, there was a run of trucks where the boots rubbed on something, but I can't remember which year. Maybe do a search for rub or rubbing?

 

[Rman]

The driver side lower boot from the intercooler rubs on my truck. I see it failing in the next 50k. I have 69k on it now and it's showing signs of premature wear. I plan on upgrading the boots at 100k as long as it makes it there!



I run a 180 degree thermostat and that has helped greatly while towing. I rarely see anything over 195 now, even up the steepest hills. I do have to watch my EGT's though.



Did they pressure check your radiator cap, perhaps your building too much water pressure and increasing the temp that way. I'm not sure what psi the cap is rated for. Probably 13-15 I imagine.

 

[Big MAK]

Knowing your boost numbers would be a huge help. Almost worth getting the gauge installed now -- just to get the numbers. Enough people know what they should be (chime in) to tell you if yours are low or not. It does sound like your boost is down -- so burning more fuel to compensate.



On the other hand -- could be the opposite! Higher boost because needing to make more power to produce same amount of work could indicate a different problem. Heck, lot's of things -- trailer brakes dragging; etc



Either way; knowing your boost numbers would be a big help. It's really the best way to tell what kind of power the engine is making and needing.

 

[Berrigan]

How about trailer brakes dragging or trailer wheel bearings? Bill

 

[DBabbitt]

Called a buddy who was a tech at a Dodge dealer for several years. He says without a doubt that my problem is the "FUEL PRESSURE RELIEF VALVE" which is located between the high pressure line and the fuel rail. Talked to the tech at my dealer again who looked at my truck. He says this can not be the problem. Anyone know anything about this item? I priced it from my dealer and it's only $455!!! this thing is about 1. 25" tall and 3/4" around! Proof that you don't have to be on the highway to get robbed!



I have included a pic of the valve circled in yellow.

 

[AKAMAC]

That is a warranty item. The Dealer can "see" the CR pressure with their scan tool. If you call a Cummins shop I'll bet you can get it for less than half that if you want to do a parts diagnostic yourself. Good luck, Mike

 

[DBabbitt]

Does anybody know What this valve does exactely and if it could be causing my problems so I can tell my dealer.

Thnx.

 

[EB]

Know all about it, I have the forth one on my truck. If it is bypassing you will foul up your injectors, just changed all 6 of mine. You can get the valve you showed for less than half from a Cummins shop. If it is bypassing it will cause the exact problems you are talking about. I also had a dealer tech tell me nothing was wrong, one week later the truck wouldn't start. Are your cranking times longer than they have been? That is also another sign the valve is going bad. It won't let the rail hold the pressure it needs to fire the injectors right. Get it fixed before you mess up your injectors, then you are talking some money.

 

[DBabbitt]

EB, Thank you, Thank you, Thank you! - I'm not crazy!! I am assuming if the valve is bypassing the engine doesn't get enough fuel so it has to work harder to keep up so the mpg goes down and the temp goes up. Sound correct? I haven't noticed longer cranking times at all. Hopefully I'm catching it early. Is there any kind of gauge I can install to monitor Rail pressure?

 

[EB]

Sorry, there is no gauge that I am aware of that will read 23,000 psi. The only people that have the instrument to read that valve is the dealers unless it is a big independent that has the $ to get it. You can get the valve from Cummins for a lot less than Dodge.



That's about all I can help you with on that. The Dodge part # on the valve is 5093113AA. I don't know if the Cummins part # will be the same or not, but they should be able to cross ck it from there. Also this is for an 03 HO engine, don't know if there is any difference between mine and yours. Get it fixed before you mess up your injectors.

 

[DBabbitt]

EB, can you give me the phone # or info for the Cummins dealer where you got your releif valve. The Cummins dealer here in Denver wants $430 for it and the dealer wants $455.



Thanks, Dan-

 

[nps]

Why don't you go to a different dealer, ask the service manager if they know how to troubleshoot a failing relief valve, and let DC pay for the part.



I hate letting a dealer touch my truck, but for $500 I have my exceptions.

 

[DBabbitt]

nps, that's my next step. I just haven't had a chance yet and I'm also trying to do my homework first too.



Thanks, Dan.

 

[EB]

DBabbitt, I sent you a PM

 

[NIsaacs]

Is your transmission ok? They can cause the symptoms you describe.





"NICK"