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Discussion Starter #1
I have a 2008 f350 4x4 all stock that is driving me nuts.I can drive all day around town in stop and go traffic and i can even floor it and all without any problems and the truck runs great. Now when i take it on the freeway at 60-70mph constant even with the cruise control on it will say reduced engine power after about 10min of driving. I will pull over and turn the key off and let it set for about 10min and then all is good for another 10min of driving. The truck runs great other than the reduced engine power.No smoke, all temps are in the middle,the boost dosent jump up or down,no noises. Only thing that i can see that is not correct is the oil level is a bit high on the stick. Any help would be great.
 

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I'm not sure how these smaller engines are but i work on cat 3516 and cummins qsk78 engines and both of these will derate if the oil level is to high
 

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well i just drained 4 quarts just to get it to the checkerd area of the dip stick. the oil was changed 1500 miles ago and it is black as black. no diesel smell no water. just smells like used oil.
 

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Take a drop of oil and put it on a piece of cardboard. If there is fuel or coolant in it it will seperate from the oil on the cardboard
 

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well i just drained 4 quarts just to get it to the checkerd area of the dip stick. the oil was changed 1500 miles ago and it is black as black. no diesel smell no water. just smells like used oil.
Sounds like fuel dilution from Regen process.
 

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well i have done the dpf delete and now the oil level is stable. replaced fuel filters and air filter. replaced trans filter and fluid. like before i can drive around all day in stop and go traffic under 50mph and all is good. but when i get up to speed 55 on up and keep it there ( about 5-10 min.)it goes into reduced power and no cruise control. other than the reduced power problem the truck runs great.
 

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I am having the exact same issue I also have dpf delete running and SCT tuner it only started this recently after I did the SCT firmware update and tune revision and in order to do them I had to have it first reflashed. At ford and then load the new tune I only run it in tow setting and have switched to stock with dpf delete as still the issue. I have now brought it to attention of SCT and apparently it's off to their engineers that was yesterday. Have you found any results with your situation as maybe it's a truck issue not tuner related thanks :icon_ford::icon_ford:
 

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I am having the exact same problem with mine right now. My truck is all bone stock, are your tuners showing any diagnostic trouble codes??

My truck is over warranty, so would like to ge this fixed myself.
Please keep updating with what you find!
 

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So you are completely stock ? Did you just have the latest ford reflash! And then this problem begun because if that is the case I would think that this is the route of my problem as well! Which would make it a ford or truck error and nothing to do with my also newly updated SCT tuner this could be great info regarding my prOblem as well
 

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Discussion Starter #14
Well i took my truck to Houma La. for a job and the problem was still there. Parked it for a week drove back to Houston Tx and it has not done it since. I had just purchased new thermostats to instal but didnt because of the job. All my research pointed to a bad thermostat. I dont know what to say.
 

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So you are completely stock ? Did you just have the latest ford reflash! And then this problem begun because if that is the case I would think that this is the route of my problem as well! Which would make it a ford or truck error and nothing to do with my also newly updated SCT tuner this could be great info regarding my prOblem as well
Yes, completely stock. No, I did not have the latest reflash...local mechanic told me to replace fuel and air filters to start with and see what happens...so I'm going to start there.

Any of you getting any codes yet?
 

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Whats your coolant level like? It could be your egr cooler is leaking and getting coolant into your combustion chamber. Do you have the steel gas tank? If so you could have a blockage problem.

the pcm reprogram is a recall that addresses several issues found here on the customer information sheet


your vehicles powertrain control module has been updated with improved fault detection capabilities to minimize engine related repair costs. below is a list of enhanced warning features in the new update:

-water in fuel reduced power mode
-engine coolant temperature monitoring
-overfilled crankcase detection (excessive oil level)
-oil cooler efficiency detection
-turbocharger overboost detection

when a fault is detected in these areas, the pcm may implement the following:

-wrench light illumination
-reduce the engine power (limp home operation)
-instrument cluster displays "reduced engine power"
 

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Ok finally a code ! But ... Not a hard code so it does not stay on after I shut my truck down I can only read it when wrench came on with the reduced engine power displaying and it was the usual various u----- codes which always are on there and p1000 and p0087 I rarely ever get my truck over 2000 rpm but I happened to be towing on the weekend and hit a long grade and it kicked down a gear ad this was when the light came on got to my destination shut truck down and have put another 800kms on since Saturday and is now tuesday and nothing it's so weird I'm personally thinking that the new reflashed has set the sensor parameters so low that it put it in safe mode and any little malfunction which I guess is good but leaves you pondering that you are in for some costly repairs lol not sure Id like to hear someone had done the same things as I with the SCT update and ford update as well would make me feel better lol I'm also hoping SCT's engineers come back with a glitch in their programming lol:icon_ford:
 

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Have had a similar issue, and it seems to happen on the same hill every time, Its a long steady grade, not towing, doing about 70-75 heading into the grade, and I can hear the truck start to struggle, and like you said it downgrades and then, this time I watched the FRP (fuel rail pressure) gauge on my livewire, and it went from 65 down to 20 and dropped down to the single digits, and then bounced back up to the 30s and then down again, and did this the whole length of the grade, was able to hold her steady at 40mph, but its really embarrassing, to have Semis I passed a mile back to come rolling by, towing a heavy load and not have a problem. Of course after I leveled off the fuel pressure still fluctuated a little, but I was able to get back up to 65 with no problem.

Normally if I stop and shut her down for 30-60 seconds and start her back up, she'll be fine. Now I originally thought this was a cruise control problem, because I had been using it a lot for the first year, but then started having the problem, just out of warranty, around 40K, luckily got the extended plan; anyways, I proved that wrong about 2 weeks ago when out of the blue, after 40K w/o an incident, going up this hill it did it, was driving w/o cruise and 70-75 and started slowing, RPMs rising pedal to the floor no boost, didn't look at the fuel pressure, but willing to bet it was very low, sure enough pulled over and it was the P0087 code.

I'm thinking its something atmospheric, the hill goes from about 800' to 1550' over a steady grade 2.5 miles long, but the last 2 times it occurred at the steeper part, same place, temp doesn't change that much, not raining, no clouds. I am literally stumped.

Sorry if I jacked your thread, but thought it might be helpful.

What year are your trucks?

Just a thought, Belgianhorseguy did you start having the issue before or after you tuned it? Mine started before. And to the OP, what tuner do you have? Curious if this is a problem with the Livewire.

James.
 

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This may seem weird put do you have a very small leak in the hpfp. That may only surface when put under extreme load? When you are going up the hill does it depend on how much fuel you have in your tank? Example it only does it when I have 1/4 tank of fuel.
 

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Cant say, I had between 1/4 and 1/2 tonight when it happened, and the time before that I was below a 1/4 so its possible. I did have the High Pressure Fuel Sensor replaced at 55K but the problem still happened. So not sure.

James.
 
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