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5.4 3v timing off?

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Brad Clayton

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Our driveability tech quit and I have been saddled with some gasser stuff. I don't fool with VCT stuff too much and have a question for yous guys.

 

This is a 2006 F-250 with 106k that has been sitting for about 2 years. The owner decided to put it back into service and it ran really bad. He replaced the spark plugs and then threw in the towel and towed it to us.The truck idles really bad, as in it runs rough as hell. I limped it into the shop and did the run of the mill stuff. This is the power balance screen shot:

 

5.4 cams out of phase pb mod.jpg

 

At this point I started thinking that the engine is out of time. I scoped the cams and this is a known good shot (yep I got 2 of em in my bay, this one needs a cylinder head) and the last shot is the truck in this thread:

 

5.4 cams in phase known good.jpg

 

5.4 cams out of phase.jpg

 

So my question is about the timing. This engine is clearly running like 2 separate 4 cylinders. Is it possible the VCT stuff has the cam locked in the wrong position? Or am I dealing with a base engine that has jumped time or has been put back together incorrectly, ect.? 

 

I have unplugged the VCT solenoids to make sure there isn't an unrequested input. I also have a P0340 so the VCT system has been shut down by the PCM. 

 

I need to mention that the alternator has a really bad ripple wave form and seems to be wreaking havoc on cam sync but I doubt it could take out 4 cylinders.   :shrug:

 

Thoughts, comments, inputs are greatly appreciated.

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I have seen bad VCT solenoids cause this when they are mechanically stuck. The seized/blocked spool valve continually sends oil in one direction which skews the timing. It might be worth a quick look to pull your solenoid on bank 1 and check its screens.

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I don't know that I've ever heard of an alternator ripple messing with all 4 cylinders on one bank and only one bank. However anything is possible in therory. If you want to rule out the alternator as an issue then I would pop the belt off and retest.

 

What does it sound like when it's cranking?

What does both relative and manual compression show?

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We had 2 this late winter had bent valves chain guides broke, but they were no starts.

I have one like yours here now. 1 bank misses relative compression is down on that side. Customer declined repair for now. 

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I apologize for the lack of info on this rag-o-muffin. I ran through the usual battery of tests, when I first got the truck. The power balance showed all right cylinders down, relative compression showed 2 cylinders down on the right side but a manual compression had both at around 200 psi. It starts pretty decent but definitely shows signs of fuel being burned at the wrong time. Other than the ridiculously rough idle and low power because of, the engine is quiet. 

 

I removed the right VCT solenoid today and it is nasty gummed up under the valve cover. The solenoids innards looked descent though and I swapped it with the left VCT solenoid and nothing changed afterwards. The customer stopped in and we chatted for a moment and you know what the guy tells me? He says don't run the engine to long because the oil pressure light will come on.   :facepalm:

 

I guess I need to hook up an oil pressure gage and let er run to see what happens. I just hate to let the engine run like that, seems like it's gonna melt down the converters.

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Thoughts?

 

If either the base timing was off, its a phaser issue or the alternator ripple affecting one cam then wouldn't you expect it to affect 4 cylinders? 

 

That is a thought for sure, however what I want to hear from you is....what is going to fix it!  :whipem:  LOL

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Our driveability tech quit and I have been saddled with some gasser stuff.

I haven't been in the business that long but is this the norm? Jam the extra workload on the existing employees while the position remains unfilled?

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Our driveability tech quit and I have been saddled with some gasser stuff.

I haven't been in the business that long but is this the norm? Jam the extra workload on the existing employees while the position remains unfilled?

Pretty much.

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I apologize for the lack of info on this rag-o-muffin. I ran through the usual battery of tests, when I first got the truck. The power balance showed all right cylinders down, relative compression showed 2 cylinders down on the right side but a manual compression had both at around 200 psi. It starts pretty decent but definitely shows signs of fuel being burned at the wrong time. Other than the ridiculously rough idle and low power because of, the engine is quiet. 

 

I removed the right VCT solenoid today and it is nasty gummed up under the valve cover. The solenoids innards looked descent though and I swapped it with the left VCT solenoid and nothing changed afterwards. The customer stopped in and we chatted for a moment and you know what the guy tells me? He says don't run the engine to long because the oil pressure light will come on.   :facepalm:

 

I guess I need to hook up an oil pressure gage and let er run to see what happens. I just hate to let the engine run like that, seems like it's gonna melt down the converters.

 Pop a cam cap off the RH side. Bet it's scored all to hell. Long block time.

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