[6-0 Momma]

Long story short:
Bought a 2004 6.0 diesel crew cab 6sp. back in February and have had issue after issue. Had turbo cleaned by professional mechanic. Thought I needed Y-pipe but that was not so. Turns out the EGR bypass was loose since the nuts had worked their way off the bolts holding it in. Same mechanic fixed this. Truck runs better, but is still not 100%. It has a Magnaflow, but you cannot hear it all the time like you should be able to. Seems like when you get in on the turbo, it cuts out the Magnaflow. Turbo still spools during this time. It also seems to cut the power when it cuts out. I am worried that something is wrong that could be damaging the motor. I was driving it today and it ran like it should..Magnaflow singing and all, but then "closed up" on the way home. Fuel filters, oil, and vacuum pump have been changed.

My question is this: What am I missing? Turbo issue? Too much air restriction? I am running out of patience. Please help me before I do something rash! :SM002:

 

[6-0 Momma]

Oil filter was also changed. I forgot to mention that.

 

[bustedknuckles]

Have you cleaned the MAF sensor?
Have you cleaned the MAP sensor, including clearing the hole into the intake manifold?
Have you cleaned the EBP sensor, including clearing the pipe into the exhaust manifold?

After doing all these, do you use Cetane additive in your fuel. Give it a double shot for a tank. Also, change your oil at the same time and drive it on the freeway for 3 or more hours. This will do wonders for you fuel injectors and Turbo.

My truck started missing after only 25,000 miles. It continued to miss intermitently up to 60,000 miles, until I decided to go on a maintenance kick. From the day I bought it until I had 60,000 miles on it I would run full synthetic 5W40 Valvoline Premium Blue Extreme. The oil is fine, but I was leaving it in for 7500 miles. Beginning at 60,000 miles I started reducing my oil change interval to 5,000 miles. The truck has been running steadily better ever since I started doing this.
All the maintenance I mentioned above is mandatory to keep these trucks running good.
Did I mention my turbo still runs great. It develops 28 pounds of boost whenever I romp on it at 50 miles per hour. Before I went on this maintenance kick the turbo would only produce a maximum of 20 pounds of boost, but not any more. I romp on it twice every day, making sure I get a full acceleration from 25 to 70 miles per hour without letting up on the throttle; once going to work and once coming home. This seems to keep the turbo in good shape.

 

[ex mounty]

EDIT belongs here since I forgot to agree with "busted knuckles."
Yes, clean the MAF (Mass air flow sensor) and use the MAF cleaner available at the autoparts store, you don't want to damage the sensor and the specific spray cleaner will not do that.
Clean the MAP sensor connection to the intake. (MAP= Manifold air pressure sensor) You can find this easily by looking for the rubber hose that comes off the intake manifold and goes up towards the top of the HVAC box on the passenger side. Make sure the hose is in excellent condition, to holes or cracks. Replace as necessary, and also check the brass nipple. Poke something in the hole (that won't fall into the hole and into the intake) so it is open and unrestricted.
The EP sensor (exhaust pressure sensor) on your 04 truck, depending on the year of the engine (which could be an 03) that sensor can be two places.
One will be on a bracket that is attached to the thermostat bracket.
Second spot (should you not find it in the first spot) is under the degas bottle, attached to the drivers side valve cover at the front FICM bracket.
Your looking for a stainless steel tube with a sensor sitting on top.
To remove the sensor, use two wrenches (one on the tube, one on the sensor) so you don't twist the tube. Use carb cleaner to get the crud off the sensor. You can use a piece of tiewire and poke that down into the tube to make sure the passage is clear, or spray brake cleaner down into the tube. You can't hurt the tube, it only goes to the exhaust manifold on the drivers side.

Oil filter was also changed. I forgot to mention that.

Do you know if a Motorcraft filter was used?
Yes, it makes a difference, a HUGE difference. Motorcraft filters must be used because Ford (and International) have a patent on the filter and its design features. In particular the oil filter is one that is of paramount importance. If you use the wrong filter, that filter will not properly engage the poppet filter on the bottom of the filter housing, and that opens a 1/4 inch hole in your oiling system that drains straight to the crankcase. That WILL have an effect on how the truck runs.

Have you tried running the truck without that magnaflow muffler? Most (if not all) states look at a Turbo as a muffler, so having one under the truck isn't really necessary. You could run a resonator in its place. You would get a little more exhaust noise, but it would not be overwhelming.

Close to 7 minutes of why you want to use only the Motorcraft filters.

 

[6-0 Momma]

Which cetane booster do you recommend? That is one thing I need to do, but have not managed to make it to a decent auto parts store. I will try to clean both sensors this weekend. To me (and I guess its my reasoning) it seems like something restricts the air flow and cuts the power, but I will give your suggestions a try.

As far as the oil filter, I bought Motorcraft. Wally World had it for less than 20 bucks, so I was all about it. I also used Rotella 15w40 oil and left it just a bit low. The dealer I bought it from had it slightly over full and just leaving it a little bit low made a big difference. I tried not long after I bought the truck to run without the Magnaflow, but there was not enough restriction for the turbo. I was having issues at the time that may have been because of a dirty/sticking turbo, which I have since had cleaned. The other night coming home, it acted like when the turbo was sticky. I may still have to put another turbo on, but it was pulling 23 PSI when checked Monday by the mechanic. I may have to give no Magnaflow another try, but I sure do love the sound. It has a 5-inch exhaust on it, but I also have a 4-inch waiting for it. I dont have room to carry my spare with the 5-inch.

I do get in on the truck almost every day, but it can go from wide open to closed as quick as stepping on the fuel. Not sure what is going on....Im scratchin my head.

 

[ex mounty]

I use the "diesel-kleen" brand made by "powersource".
It is one of the very few things I buy at Autozone.
(The others being wax, brand name oils and air fresheners.)
I use the gray bottle in the summer months and the white bottle in the winter. The white bottle has "anti-gel" compounds in it that I need in my climate.