Strange Power Loss Issue-Help?!

derek witt · #1 (**permalink**) 06-17-2008, 01:34 PM

Hi Guys, been fighting an weird issue for a long time without any resolution. Truck in an 07 Harley with 35000miles, stock.

Problem- when towing ( either my 6000lb boat or 9000lb trailer)and under a good load, it is gutless from 1/2 throttle to full throttle. It barely makes a difference between the two, and won't barely pull 60mph even up a moderate grade. When held wide open in this situation, it kind of pulses a couple of hundred rpms and just doesn't make any punch -and on two occasions it stumbled a little until I backed out of it. Also , the fan seems to run alot as well. *Note - Even unloaded it seems a little flat on top, but doesn't nearly show as bad as when towing.

Boost is not a problem it makes 28lbs or so under these situations. ( I checked the cac tubes and hoses to make sure and all is good)

Thought maybe head gaskets, but it isn't puking anything and doesn't smoke anything on startup or show any signs of any leakage.

That leaves fuel delivery. Fuel filters were changed and the problem seems somewhat reduced( maybe just wishful thinking) but certainly still exists. Anybody heard something like perhaps a fuel pump not making enough pressure(?)

Truck has been to dealer twice for this and it throws no codes. They have done the old "replaced egr, everything seems ok, its hard to tell without codes" deal.

Any thoughts from the 6.0 gurus? Thanks, kinda tired at being embarrassed
when pulling my moderate loads and having the Dodge and GM boys blowing by.

BPofMD · #2 (**permalink**) 06-17-2008, 04:25 PM

You COULD take the diesel mech for a spin. Set up the appointment to do so..they should plug in their electronics and be sure you have your biggest load behind your tailgate! Then when those Durges and Chubbies drive by ya, you can ask the mech...."WHY"?

derek witt · #3 (**permalink**) 06-17-2008, 05:41 PM

I am actually taking my trailer down to drive with the service mgr and tech on Thurs. I just want as much info to pass onto them as possible. Thanks.

bigredtruckmi · #4 (**permalink**) 06-17-2008, 09:41 PM

I think you are on the right track of fuel delivery or lack of. You might have gotten a bad batch of fuel and plugged filters. It might take another change to clear out the problem. Did you open up the filter off the frame and take a good look at it? If it had a lot of stuff on it there might be the problem. I had this problem on vacation. No power after a fillup in nowhere land. It took 2 changes of filters in 3K miles to get back to normal. These engine are very sensitive to fuel flow/pressure and quality. I personally use a premium fuel and have had great mileage and no problems with fuel issues. I also change fuel filters and every other oil change. 10-15K

derek witt · #5 (**permalink**) 07-01-2008, 06:26 PM

Thought I'd give an update to my lack of power issue. Took my trailer to dealer and we went for a ride on the highway. Sure enough when we got to a decent hill and I put my foot into it a little, nothing. It just lags along about 50 up this little hill and thats it- right to the floor. Lots of boost - but no power.

Dealer thought maybe fuel pump as some of you mentioned, put in a new one and she is still the same. Gutless under load, and the cooling fan fan runs alot. Any further thoughts? Thanks.

Paymaster · #6 (**permalink**) 07-03-2008, 09:28 AM

I got the same problem too. Bumping this to the top.

jmaskew · #7 (**permalink**) 07-03-2008, 11:37 AM

I had the same problem last year. The engine was defueling due to overheating. Turns out the head gaskets were blown.

derek witt · #8 (**permalink**) 07-03-2008, 01:28 PM

Thanks jmaskew- it very well could be headgaskets. Everything else has been checked/replaced. The only thing is it really doesn't show the classic signs of headgaskets - white smoke, low coolant, no codes etc. Did you have any telltail signs or just simular symtoms? Any guidance is appreciated.

Note -I just called my dealer again and they said ok to checking/changing headgaskets. ( They have been great through the whole ordeal)

jmaskew · #9 (**permalink**) 07-03-2008, 02:43 PM

Quote:

Originally Posted by derek witt

Thanks jmaskew- it very well could be headgaskets. Everything else has been checked/replaced. The only thing is it really doesn't show the classic signs of headgaskets - white smoke, low coolant, no codes etc. Did you have any telltail signs or just simular symtoms? Any guidance is appreciated.

Note -I just called my dealer again and they said ok to checking/changing headgaskets. ( They have been great through the whole ordeal)

It always helps to have a great dealer! I had some coolant loss, white dots around the degauss bottle, no white smoke. My CEL didn't come on ever. The coolant loss through the degauss bottle increased over a period of 4 weeks before I could get it in to be fixed. It would overheat (fan came on) driving around empty. The last week or so I could smell coolant in the cab when at stop signs. The only coolant loss visible were the white dots on the degauss bottle. Go check your degauss bottle for little white dots. Hope this helps.

Paymaster · #10 (**permalink**) 07-17-2008, 04:55 PM

My problem was carbon. Fouled EGR valve and a sensor. $938.00

bismic · #11 (**permalink**) 07-17-2008, 09:55 PM

Just fyi (may not apply) but the EGR system is covered under the 5 year / 100k emissions warranty with no deductible.

BowTieHatr · #12 (**permalink**) 07-18-2008, 08:02 AM

i had a bucket truck doing the same thing. the truck would boost atleast 30 but lack the balls to move. the truck was over boosting and the pcm was defueling the truck. the turbo would stick when the truck was super hot and when i tore the turbo apart, the unison ring was frozem to the center housing. go drive your truck as hard as you can and see if you can get it to do the "turbo fart". if so, i would start there.

Paymaster · #13 (**permalink**) 07-18-2008, 08:36 AM

Quote:

Originally Posted by bismic

Just fyi (may not apply) but the EGR system is covered under the 5 year / 100k emissions warranty with no deductible.

Got 115,000 on my truck. It has been to my dealership 4 times for the same symtom,(while under warranty) missing and power loss while hauling. They claimed to have fixed it each time.When I took it back to them complaining that the problem persists they told me I was on my own due to warranty period being over.I took it to a different dealership and had the repair. I will find out whether it is fixed today. I am hauling my 5th wheel camper to Chattanooga for the weekend.

Paymaster · #14 (**permalink**) 07-21-2008, 08:59 AM

Well no issues this weekend. Haulded my 36" 5th wheel camper 300 miles and no problems.

derek witt · #15 (**permalink**) 07-21-2008, 11:59 AM

Hey guys - update. My great dealer as previously mentioned, did the head gaskets last week and sadly it was not the problem. Same deal when towing my 5500 lb boat this weekend.

Makes tons of power and pulls good up to a certain point- then when I really have to get into it up a hill (and make 28 -30lbs of boost) it just flattens out at high boost and makes no powder.

Bowtiehter, maybe you have something there, it does feel like it is defueling, and it the fan runs alot in this situation, which led to the thoughts of perhaps headgaskets.

Is it normal to make that much boost on a 6.0 ? PS- it doesn't feel like the turbo is sticking. ie, when I back out of it comes down quickly.