2005 Ford F350 5.4L Variable Camshaft Issue

[Tim Martin]

I have this 2005 Ford F350 with a 5.4 VIN 5 engine and 136,800 miles on the clock. The issue is very erratic engine power, flashing "Check Engine" light and a DTC P0300. This only happens while going down the road. Sitting here in the shop there is no issue. So, after checking fluid levels and fuel pressure (36psi KOER) and erasing the trouble code, I head down the road with my scan tool connected. The only issue I am seeing is what I would call a variable camshaft timing issue. Bank one variable camshaft timing numbers are at zero and never change. Bank two numbers are ever changing from zero to 45 degrees advance. Meanwhile, no trouble codes appear for the variable cam timing even with so much difference in bank numbers. I do not have a terrible lot of experience with these VIN 5 engines but something is telling me that there cannot be so much difference in numbers without engine performance being affected. I will admit that when I take off from a dead stop, the engine really surges with rpms going up and down in the five to six hundred range difference. This rpm range difference is easily felt in performance. So, I am trying to figure out where the problem lies with this engine. Can anybody offer some ideas?

[steven kiser]

Not 100% sure but I believe if you take out the VVT sensors you may find some metal filings in the screen. Usually we run the truck until it's reached operating temp and trying not to get any contact burns remove the pressure control solenoid's, flush the pressure ports with solvent and air pressure. Replace solenoid's, change oil and we change over to a synthetic, clear codes and give it a good run. There may be a chance of a broken wire so do a quick resistance check and about this time around here we look for critter nests and chewed wired. Good luck, but you will probably find the valve stuck because of a piece of metal.

[Tim Martin]

Got it. Now, my next question I am trying to find an answer for is "How can I know what percentage or duty dycle the PCM is telling the actuator to do?"

[steven kiser]

I believe my Snap On Scanner will allow us to see exactly what the readings are. Just beware, the PCM will make adjustments trying to work around any drivability issues sometimes clouding diagnostics. The multiple misfire code most likely happens going down hill after climbing up. I can't sat with 100% surety but I don't think I ever replaced a PCM on a Ford for this issue or had any wiring issues. We just pull the solenoid and with a Power Probe activate and deactivate it. Usually they just would hum or work one way but not the other. Again, if it needs replacing I strongly suggest cleaning the oil pressure bore. On occasions if there is heavy metal fragmentation I'll slowly spray Brake Clean or another solvent into the bore and using a piece of brake line and a suction source clean it out, attach a blow gun to the line, make sure it's bottomed out and blow air in hoping to force any debris out. Good luck and I'm sure after you work through this one your way the next time it will be a breeze.