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6Bucs, Ford Senior Master
Category: Ford
Satisfied Customers: 949
Experience:  Ford senior master tech, 18 years experience.
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Ford F250 SuperDuty Pickup 4x4: I have a 2007 f250 with 5.4.

Customer Question

I have a 2007 f250 with 5.4. It has 34,710 miles. It is used for ranch work almost all offroad travel. Have po305 and p0012 codes. Have replaced both vct solenoids with no change. I checked the voltage output from bank 1 cam sensor and compared it with bank 2 sensor and both were identical. Would you say that the next step is the cam phasers? Have switched 1 and 5 coils with no change. I don't have the tool for checking compression with those plugs. I had the plug out and it looks ok. I also removed the coil wire with the engine running and it makes a definite miss. I would say that cylinder is firing fine. The po305 doesn't store until you drive it down the road. I have an actron scan tool and it says the top fix for the po305 is to replace cat converters. I did a vacuum test and it showed normal, about 17" at idle with no dropping as the rpm was increased. It doesn't seem like the converters are bad but when you drive it and it misses, it does lose power and have similar symptoms to a plugged exhaust. I would like to be a little more certain before I order new converters and dig into the cam phasers.

Thank you for any suggestions.
Submitted: 5 years ago.
Category: Ford
Expert:  6Bucs replied 5 years ago.

6Bucs :

Hello and welcome to Just Answer. My name isXXXXX for the delay, we may be having a technical issue with the chat function.

6Bucs :

So, first off, two things. Can you supply the VIN for me and also is this your personal vehicle, or are you a tech at a repair facility?

6Bucs :

The reason I ask is that the phasers and the converters are most likely covered under emissions warranty. I can check that for you with the VIN.

Expert:  6Bucs replied 5 years ago.

The cam phasers are very susceptible to sticking and usually fail due to oil maintenence issues or oil supply problems.

These engines are notorious for phasers and VCT solenoids sticking from oil feed problems to the cylinder heads. The bad or sticking phaser or VCT solenoid is usually the result of the problem not the root cause. Here is a list of what I check or replace on these every time I get one in with phaser noise, VCT codes, cam sensor codes or misfires caused by VCT issues. Before any disassembly the PCM data pids for VCT error correction should be monitored to confirm it is a VCT issue. If the vehicle won't run, a compression test can also verify the VCT problem.


  • Oil Pressure. Any thing under 25 at idle will cause phaser issues. Oil pressure needs to be steady and not fluctuating. If low or fluctuating suspect crankshaft thrust bearing wear. This can be verified by a simple end play check. Also if engine is sludged in the least amount there could be oil starvation to the valve train which is also very common on these and can be verified by pulling a few cam caps on each side, it will be obvious if the there is an oil supply issue to the valve train by the condition of the caps and journals.

  • VCT valve body/solenoids. Have seen many issues with solenoid plungers sticking and restrictions in valve body due to plugged or collapsed screens.
  • Timing chain tensioner gaskets blown. This will cause oil pressure bleed to the valve train and affect phaser functionality.
  • Camshaft phasers sticking due to contamination or low oil volume/delivery pressure.
  • Crankshaft endplay, I don't bother fixing the engine if endplay is over .010
  • Oil pump, I change if there was any evidence of sludge or varnishing. There are passages in the pump that clog and can cause oil starvation problems.

In short if I don't find oil pressure concerns and my cams are in good shape I usually replace the phasers, VCT bodies, oil pump and tensioners on every one of these. Ford has updated these part numbers several times with improved engineering designs.


For the misfire, I have never heard of a catalyst causing a single cylinder misfire. Ford updated the spark plugs to correct misfire issues. It would be a good idea to physically remove the plug and inspect the electrode.


Usually if a converter has failed, it is due to contamination. It is important to leak test the injectors if a converter is suspected to have an issue.


Customer: replied 5 years ago.
Thank you for your reply. I am the mechanic for a cattle ranch. Do you think it would be wise to take the vehicle to the dealer and have them look at it for possible warranty repair? We did not purchase extended warranty for this pickup and it is over the 3 years, 30000 mile coverage. I could give you the VIN but it wouldn't be until tomorrow. There is more to this pickup's story. I just recently had to put a new engine oil pan and pump pickup on it because the operator hit a large rock and smashed the oio pan putting a big hole in it. I know that the gauges all flashed at him before he noticed the oil pressure. The engine's oil pressure is in the normal range at all times and doesn't make any abnormal noises. Could the poo12 code cause the no5 cyl misfire? poo12 code has to do with the passenger side of the engine correct? No5 cyl is on the driver's side front on the engine correct? I would think that a plugged/restricted converter would throw a po300 code. When you check for restricted exhaust, which method do you use?

Thank you, Aaron
Expert:  6Bucs replied 5 years ago.

Since the phasers control timing, they can be covered under emissions warranty if the problem is just sticking phaser(s) (and the converters if there is an issue) Emissions warranty is different from the new vehicle warranty and for your 07 the coverage was either 7 years 70,000 miles, or 8/80,000. The VIN can tell us that when you get a chance.

You are correct about the location of #5 cylinder and the right bank for p0012 dtc.

For restricted catalysts, the easy check is just to loosen the nuts to the manifolds and drive it. This only really works if plugged pretty well. We usually remove an oxygen sensor and check for vacuum while briefly performing a wide open throttle.

I don't suspect the misfire code is caused by the exhaust, or the VCT code.


6Bucs and 4 other Ford Specialists are ready to help you
Customer: replied 5 years ago.
Here is the VIN for the 07 f250- 1FTSX21507EA52400. l changed the spark plug on 5 this morning and so far no check engine light. I suppose I should change the rest of them. It definitely had a much larger gap than the new one. $24 each for those new ones! How do I monitor the PCM data pids for vct error? I don't see that option under monitors with my scan tool. Maybe need an OE scan tool? I'm assuming oil press. not to be a problem if the dash gauge always shows in the upper half of the normal range.

Thank you, Aaron
Expert:  6Bucs replied 5 years ago.

Hello again, Aaron. The oil pressure really needs to be checked with a manual pressure guage, because the instrument cluster guages are voltage regulated, meaning if the oil pressure is 14 or 90 psi, it will show at the default 1/3-1/2 position. Otherwise, every time the rpm changed the oil pressure guage would fluctuate and the owner might become concerned (if this was an true pressure guage).

If your scanner can read live sensor data, you want to look at VCTADV 1 and 2, and VCTDES 1 and 2 to compare.

I'm having a bit of trouble getting the VIN to match parts coverage. The Ford webpage may be having difficulties. I'll try again in a bit.

I always use the OE diagnostic equipment and I'm not too familiar with the many aftermarket testers specifically.

Customer: replied 5 years ago.
I was wrong about the misfire. On the way back the check engine light started flashing and I could tell that the PCM was shutting off that cyl. You could definitely feel it. It seems that it only sets the code under acceleration, not at idle for instance. I'm pretty much down to compression problem or an injector. I guess that it could be a pcm supply voltage problem or a bad driver in the pcm. Is a noid light the best way to check the injector? Maybe there should be other codes present if the misfire was a voltage or PCM problem?
If the misfire was caused by valve train problems a compression test probably wouldn't show it. I don't think that my scan tool will do a cyl balance test. The pcm will also change fuel trim to try to adjust for a misfiring cyl right? I noticed that one side fuel trim was different than the other. I'm thinking that I should take it in to the dealer and have them check it with their scan tool before I do anything else. Where is the easiest spot to check oil pressure with a mechanical gauge?
Expert:  6Bucs replied 5 years ago.

Usually there will be codes for coil circuit a,b,c failures with electrically related concerns with the coils. Not all the time, though.

To verify the injector pulse, yes, a noid light is the easiest way.

If you run a compression test, run it with the engine disabled so it won't start, then do a

running compression test also. Usually one or the other is able to identify a valve train issue.

The PCM will add fuel to try to help out a cylinder that is misfiring, you're right there also.

You want to check the oil pressure at the oil filter housing. Remove the oil pressure switch which is screwed into the housing right behind the filter and put the guage in there.

Yes, it might be less hassle and cost effective in the long run to have the dealer run a few tests with their equipment.

Ok, I think I hit on all of those questions. Ford site is still down, there's a message there about updating the servers. I have the VIN stored on our post here, so I'll keep trying it periodically.