Hey guys, I am new to the scene. Recently bought a 2004 Excursion with the 6.0 psd and 85,000 miles on it. Heres the problem, I was towing about 4500 lbs on a flat level highway doing about 70mph in tow mode and I notice a droning noise coming from the exhaust. As I drove, I realized the turbo wasn't producing any boost. Truck still drove fine but I had to be careful how hard I pushed it because the EGT's would easily climb well past 1250 if I didn't let up on the skinny pedal.

Truck has the following upgrades:

Bulletproof diesel oil cooler
Bulletproof diesel EGR cooler
Garrett Powermax turbo
MBRP 4" turbo back exhaust
Metal intercooler tube

I am monitoring it with an Edge CTS unit with egt probe. At the time this happened I was running a SCT tune for towing +65hp. It was a tune on the X4 programmer that came with the truck. At the point this happened, I had already towed the boat almost 4 hours without any problems.

The Edge CTS read these 4 codes:

P0069 - Barometric Pressure Correlation
P0470 - Back Pressure sensor circuit malfunction
P0478 - Exhaust pressure control valve malfunction
P2262 - Turbocharger boost pressure not detected - mechanical

Where should I start? I checked under the hood and didn't see anything obvious, looses hosed, fluid any where, etc.

Thanks in advance for the help!

 

This should be moved to the 6.0 forum! Check the tec folder in the 6.0 forum, scroll down from the excursion one.

 

Indeed!

Stewart

 

I would be looking at the EBP and Map sensors, double check the map hose to for cracks

 

Also check the EBP tube. If it dirty pull
the EBP and tube off the manifold and clean it out.
Some have said a weed whacker line works good to
clean the tube out.


Sean

 

Thanks for the input guys. I have pulled the EBP sensor and tube and cleaned them. Not much carbon and definitely not clogged in either. weed whacker string worked well.

Also checked the 1/4" tube to the boost sensor and it was in good condition.

My EGT's are way off too. When idling they are way lower than normal. When under load, its very easy to surpass 1200 if I am not careful. Obviously a lack of power too.

Anything else you suggest I check? Thanks.

 

Took the truck for a drive while watching the Barometric Pressure, Exhaust Back Pressure and Manifold pressure on my Edge CTS. Here were the results:

Barometric Pressure stayed at 14.4 psi the entire time.

Manifold pressure ranged from 30 psi at idle to above 100 psi around 2000 rpm

Exhaust Back Pressure was either *** or 0. I never say an actual reading on it. Since I already cleaned the tube out, should I proceed with replacing the sensor? I would think it should of had a reading greater than 0.

Thanks!

 

Barometric pressure is 14.9 at sea level and will only go up or down a little, depending if a storm is coming.

My EBP ranges from low teens to in the 20's. I'd say if it never read anything, time for a change.

What was VGT, were the numbers changing?

 

I had a no boost situation with mine. KOEO EBP, Baro and MAP should be similar around 14.5. Mine turned out to be a faulty FICM and a melted CAT. As suggested to me, check BARO, MAP and EBP, check FICM voltage, should remain above 47v, KO, cranking and running. Backing off the cat joint on the header pipe side will reveal a blocked cat. Unplugging the VGT solenoid while idling, you should hear a change in exhaust note and intake noise.

 

I would pull the EGR valve and clean it with carb cleaner, just be sure to keep the carb cleaner out of the electrical (top) side of the valve. I would also pull the throttle body where it enters the intake and remove the butterfly valve if it is there, there is just a couple of fasteners that hold it to the shaft. You also may have to replace the wiring pigtail at the EBP sensor.

 

Do you know what flash version is in your truck? The inferred strategy could change troubleshooting procedures and make you scratch your head a little.

Inferred EBP Description
06E17 for 2003 & 2004 MY 6.0L F-Series, Excursion built to 9/29/2003 eliminates use of EBP sensor.

 

I have no idea what flash it has. Is there any way to find out? Even if it has this flash to ignore the EBP, would that cause it to read 0 all the time?

 

Update - Pulled the EGR valve, here is a picture of it:



WHat do you guys think? I didn't think it looked too bad or bad enough to be the cause of the problem. I went ahead and cleaned it anyway. Put it back in and took the truck for a drive. To my pleasant surprise, its back to its normal self. Boost is great and obviously the truck has plenty of power again. EGT's are running normal again. The CEL cleared and I reset the DTC and they have not returned.

I am going to keep driving the truck and monitor the MAF and VGT values and see if the problem returns. I just find it hard to believe that the EGR was to dirty based on others that I have seen. Maybe unplugging and replugging it reset the valve or something along those line.

To answer the VGT question, I didn't start monitoring that until after I cleaned the EGR valve but the values are changing.

What do you guys think? Did I find the problem or is there something else I should keep looking for. Thanks.

 

Does not look bad at all. But what ever you did would seem to have
fixed the problem.

Keep the rubber side down.


Sean

 

Where you been Bret Good call give that man some or Reps