Hi,

I have a 2006 Ford F-250 with about 111,000 miles on it. As of recently I have been having issues with the Check Engine light coming on. I have been back to the Ford Dealer 5 times in the last two weeks for the same issue. They keep throwing sensors at it, have replaced the EGR 1 time. I am getting frustrated and they don't seem to have any answers. I don't have a tuner installed. I bought the truck from the same dealership as it sits today. It may have had a tuner then but it has since been flashed from the computer after one of the many times I had it in for injectors, which I seem to go through atleast 3 every 6 months or so. The only mods to it are the larger down pipe with 4 inch exhaust back that eventually comes out as duals. It has a banks intercooler(the big red thing at the top front of the motor) and cold air intake. We are down to taking the banks stuff off and putting on mechanics stock equipment from his truck to see if that works. Does anyone have any ideas, please help!!!

 

Your EGR valve, and probably the EGR channels in the intake manifold are plugged up. It's an easy fix to do yourself.

Pull the EGR Valve. If the top half is caked solid with coke, then use a small screw driver to chip it away and into the trash. Then spray that area with carb cleaner, but be very careful to not get that stuff into the valve itself - there are a few breathing holes there.

While it's off, you want to get a shop-vac, and use a nice long 6" or so screw driver to do the following. With the shop-vac on and covering about half of the hole, use the driver to probe the top channels of the intake. That's where the engine gasses come in from the cooler, and it was packed with coke on my truck when I first got it. Probe around, careful not to etch the aluminum manifold, until you are confident you got most of it.

(EDIT - Reinstall the EGR valve at this time - make sure the O Rings are in good condition, maybe replace them if you feel like being extra safe - I think they're like $10 from the stealer)

Then, run a higher-concentration of diesel-kleen than normal (I use a full 40-gal treatment bottle in my 3something gallon tank when I am trying to really clean the system) and drive it hot and hard (but not too hard that the system is not using EGR - more like find an interstate where you can go 75 or 80 or so so you're running it harder than normal but steady enough to run EGR) for a little to try and get that gunk fully cleaned.

 

With it going through injectors have you had the dynamic fuel pressure tested? It simulates wide open throttle, the fuel pressure at WOT should never drop below 45 PSI. Also running a fuel additive that provides lubricity and cetane boost like the motorcraft cetane boost or stanadyne performance formula is a good idea.

 

I would think the sealerships have already tested fuel pressure to find the root cause, but that's something that should be tested to find the root cause of the problem.

0401 is a low EGR flow, and the main causes are either coke has completely closed the EGR circ, or the VGT system is starting to act up. When I got it frequently, I found that the passage was plugged up almost all the way to the EGR cooler.

If the EGR passages are clean (which they probably aren't) then have the dealer start testing the VGT - unison ring etc.

 

+1 on the VGT. That code is not really a big deal, just annoying emmisions code. Could be a sticking turbo as chewed suggested.

 

They have replaced the EGR, last September they completely cleaned out the intake because it was coked up really bad, and that is when the problem really started. When i got it back from the intake being cleaned out, the check engine light was still on and the Mechanic said that once they do the cleaning the EGR usually won't work properly even though on the computer it says it's ok.(This was rather confusing to me.) They cleared it and said if the problem persisted to bring it back. The light came back on and then went out and never came back on until I started having the injector issues this last time round. They fixed the injectors and couldn't get they check engine light back on, which once I got the truck back it didn't take long for me to and I returned it with the same result every time I pick it up. They have replaced a couple different sensors like the MAF sensor, a line that had a hole in it, and eventually the EGR. As far as the injectors go, I looked up some videos on powerstrokehelp.com and saw the part about the dynamic fuel testing, and I requested that they do a static and dynamic fuel test, and they said they had already done that and everything was ok. I have heard about a blue spring upgrade and have been giving this some serious consideration in doing in hopes of fixing my fuel injector problems. I usually run either Diesel Kleen or Lucas fuel injector cleaner, but still end up having the injector issues. As far as the EGR code goes, they have contacted the Ford hotline and done several pin point tests to try and resolve this without any improvement. I'm just at a loss, and kind of at the mercy of the dealership and their mechanics who haven't impressed me in anyway. Luckily I had purchased an extended warranty so all of this has been covered since the first time I brought it back in, but they are coming to the end of the line as far as options go or are giving up to me as it sounds.

Thank you all for your input, it helps and gives me some ideas.

 

Chewed: I do a lot of highway driving so I'm constantly running between 75 and 80mph and this seems to be when my light comes on, I will try and do the diesel kleen again when I get the truck back and see if that helps.

 

Does the diesel kleen or lucas injector cleaner have a lubricity additive? If not I would start running one like motorcraft cetane boost or stanadyne performance formula. The ULSD has lost some of its lubricating qualities through the process of removing the sulfur and it is hard on the injectors. The motorcraft cetane boost ( which is what I run in every tank ) is like 8 bucks and will treat like 150 gallons, I have also used the stanadyne product as well. Also not trying to side track your thread but a switch to a full synthetic oil ( 5W-40 ) isn't a bad idea either, its a good year round oil and the injectors love it. For what its worth the cetane boost will also help the fuel burn better and can help with the coking problem.

 

Has the dealer basically replaced every sensor that deals with egr flow and you are still getting a code? I occasionally get a P0401 code also but it clears and doesn't come back right away. I did clean the turbo and that seemed to make it less frequent. I think its just the nature of the 6.0 to throw that code.

 

Have you by chance removed and cleaned the IAT2 sensor?