Looking for a good 5.4liter mechanic

My 2008 f150 5.4 has been giving me the raspberries lately. Normal driving regardless how much driving everything is fine.

But lately I've noticed with a trailer following me and I go about 14 miles or more when I come to a stop my motor will miss pretty bad and you will here a knocking sound. Get it just above idle and things smooth out very nicely.

At first I thought it needs timing chains but that wouldn't come and go depending on the style and amount of driving.

Is it possible to have some bad vvt oil selenoids? Once things cool down even with the trailer it is fine until you put some more miles on.

I'm hoping you don't tell me to put new phasers in I'm not looking forward to that.

the variable cam timing is operated by OIL... Your OIL is getting hot / thin out / and not doing its job with the VCT, loosing pressure.... when it cools off, things work better.... when the engine speed picks up 200 RPM from idle, the pump pressure goes up and you dont have a problem.

Edited by steve(ill) - Yesterday at 9:23am

Steve you make very good sense. I wouldn't consider 165000 miles high miles but perhaps it is high enough in this case.

I'm sure i put 5w20 in it the last time I changed oil. What are your thoughts on Lucas? I've had great success in regular motors with no vvt but I'm not sure how this style motor would feel about having Lucas in it.

Are there any codes coming up or is the check engine light on, if in doubt you can use a scanner in auto parts lot to see codes. If that's not an option literally Google your truck model engine etc and issue you're having as a sentence in the Google search and a whole list of advice will come up, none of which I saw mentioned using thicker oil, you have to watch going thicker as other tolerances in bearings are very close and could cause other issues. Let us know what you find out. I'm more of a GM person but curiosity got the best of me so I googled like I mentioned above. Good luck. While you're at it see if you can get a solid answer for where the blue fluid in the oval goes for ol Freegas. Just had to throw that in but he's probably waiting on a train in search of a fish samwich.

If low oil pressure at idle is indeed discovered to the issue, a couple routes can taken;
Make an adjustment to the engine ECM, to have the ‘low idle rpm’s’ bumped up to hopefully enhance oil psi at idle.
Change the oil and filter to a higher weight of oil, pay attention to the the lowest number of the grade of oil, the higher number is irrelevant at this time.
A 10w30 is thicker oil that 0w40, it is simple physics, oil gets thinner as it gets warmer, no ‘higher 2nd number’ is gonna change that. I don’t care how many additives/emulsifying ingredients are added, the motor oil will get thinner as it gets hotter.
There very well could be a mechanical issue with the engine, oil pump itself may be getting tired, and less able to produce pressure as the pump gets hotter.

hmm.. anyone add an oil 'cooler' somewhere ?

More on what LARS was saying.. Here is a graph that shows the oil viscosity vs TEMP... to the left is COLD ENGINE... to the right is HOT ENGINE... Note that the 10w oil when COLD is thicker than the 20 or 30 wt oil when HOT....

Edited by steve(ill) - 6 minutes ago at 9:28am