2007 screw 4x4 5.4 3 v 130 k miles

My truck runs great plenty of power e.t.c. But sometimes when I pull up to a stop light it acts like it's running on half the cylinders. shakes like a diesel. if I put it into neutral, rev the engine to 2 thousand rpms it goes away. this only happens when it's warm, when it's cold no problems. I had this happen once before a couple of years ago on a vacation but chalked it up to bad gas, as one tank later it went away.

Now it's back, This is what I have done.

new fuel filter
blue stabil fuel cleaner
2 tank fulls of teckron 4 bottles using premium gas chevron.
maf cleaned
throttle body removed and cleaned
new air filter
new motorcraft spark plugs also used dielectric grease
oil change every 3 k (sometimes I would forget)
trans fluid change with filter flush

I'm thinking cops but don't want to keep throwing money at the wrong problem.

On another note changing the plugs was not half as bad as I expected.
I took the truck on a short drive just enough get it up to operating tempeture pulled the cops and used a 3/8 impact air wrench to remove the the plugs they all came out easily except hardest one to get to. (passenger side back assuming no 8) I had to pull the computer box and use the lisle extractor tool to remove it. the tool worked like a champ. Having never removed the plugs before, doing it in two hours made me pretty happy

I watched a few you tube vids on cam phasers but don't really think that's the issue. because it doesn't happen all the time. almost forgot it throws no codes.

any ideas ??

Thanks Ray

 

I was going to suggest plugs since my truck on original plugs at 112k has recently done this here and there. Kind of want to say it may just as well be a COP now.

 

I had this exact same problem. I can tell you that it definitely is the Variable Camshaft Timing (VCT) system. That doesn't necessarily mean it's the phasers though.

What's happening with your truck (and happened to mine) is low oil pressure at the phasers. The whole VCT system relies on your engine oil pressure to operate (kind of like hydraulic fluid in heavy machinery). When your oil gets hot, it gets thin and oil pressure goes down. Apparently the system needs a certain minimum oil pressure to work correctly and you're not getting it. When you raise the RPMs, you're raising the oil pressure - enough that the system can correct itself. Any this won't happen to you when your engine is cool because the oil is cool/thicker and the oil pressure is automatically higher.

I've verified this with my Gryphon tuner set to display the Camshaft angle. When driving normally, the camshaft angle (or phase I guess) is varied between 0 and 50 something degrees. When you're idling, it should be at 0. When I pull up to a stop sign with a hot engine and give it a little gas, the truck would shake terribly and I'd notice that the camshaft angle would be 20 or 30 degrees. Rev the engine to 1500-2000 rpms and the camshaft angle will correct itself.

As for the cause of the low oil pressure, it could be leaking timing chain tensioners (which also use oil pressure to operate), cam phasers binding up, clogged oil passages, weak/clogged oil pump, or something else. Since this problem happened for the first time immediately after I changed my oil (I used Royal Purple Syn 5w20), I decided that it could be PARTLY oil related. My temporary fix is that I changed my oil again this time using Mobil1 Syn 10w40. I'm not recommending you do the same, but a thicker oil does mean higher oil pressure. In my case, switching the oil has "fixed" the problem.

I'd like to know the actual cause of this, but I'm not ready to drop $2-3K at the dealership to find out.

 

That's great to know I'm going to switch oil tonight and give that a try. Thank you very much. I will post the results.

Ray

 

You're welcome. I am sure there are lots of guys out there who wouldn't dare put anything other than 5w20 in their engines, but it's your truck so do what you want.

There's other people out there who have apparently put 15w40 Rotella (diesel variety) oil in their 5.4Ls and say that ALL the noise goes away - even the typical clicking that happens all the time. In my case, I have also read a previous dealer message, which has been since cancelled by Ford, which said to put either 10w40 in "noisy" 3V engines. So I decided to start with the 10w40 and see how that worked. You might be able to get the same results with a 5w30, depending on what is causing the low oil pressure.

I've only got 63K miles on my truck by the way. Congrats on going twice that long before yours started knocking.

EDIT: here's the Oasis message that has been cancelled.

 

Great information, It would only make sense with my engine having 130 k on it, I'm sure the tolerences are greater just from normal wear, dropping the oil pressure just a little, or maybe a semi blocked oil line. Thanks again I cant wait to give it a try.

Ray

 

I tried 10/30 mobil 1 and still have the same issues, I'm going to drain it and put some 10/40 in. I stopped by the ford dealer today and had a mechanic listen to it, He claims it's not getting oil pressure in the top end and I need a new motor at a cost of 7500.00 bucks. He said he has seen this before. I'm not giving up it just yet.

 

It may just be sludged up, try AutoRX. Follow the website instructions EXACTLY.

 

You may or may not know this but the first number in multi-grade oil designation, like the 10 in 10w30 refers to the cold viscosity. The second number refers to the hot viscosity. Since your problem is with hot oil pressure, make sure to increase the second number. You could use 10w40 or 5w40 if you can find it.

If your engine oil passages are all "sludged up", thicker oil won't help though.

 

This is the part I don't understand, when my engine is cold the engine oil would be 10wt at start up. With that I have no issues everything works just fine. the engine gets to operating temp the oil should thicken to 30 wt correct? 10w30 So if this is the case why would it work fine at 10 wt and not 30wt when it's warmed up?

Thanks Ray

 

The oil definitely doesn't thicken as it gets hotter. The first number with a "W" after it is apparently winter designation, not weight. From Wikipedia: The 11 viscosity grades are 0W, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, and 60.

With a multigrade oil, you're getting the benefit of cold-starting lubrication found in a 5w/10w winter oil, plus the thicker hot viscosity of a SAE 30/40 weight oil.

I'm not sure really how the mulitgrades work, but for your purposes just worry about the second non-winter number.

EDIT: Short story - all oil gets thinner as it warms up. You wouldn't want to use a 5w straight oil in summer because it would be way to thin when it got hot. You wouldn't want to use a SAE 30 or 40 oil in winter because it would be too thick when it was cold. Back in the day people changed their oil in fall and spring because of this.

 

O.K. Thanks, going to try the 10w40.

Ray

 

After a couple of days using the mobil 1 synthetic 10w30 the issue seems to have gone away. I'm keeping my fingers crossed.

 

Do you mean 10w40? I've tried Mobil 1 10w30 and 5w20 and neither have worked for me.

 

Yes 10w30, I was going to switch a couple of night ago to 10w40 and just didn't have time. My thought was to try 10w30 as a stepping stone and at first it didn't work, but for now, no issues maybe it just took a little time to get thru the system.