I have 2007 F150 that has a tendency of running real rough when idling. I took it in and they said VCT solenoid was bad so I had them fix it, cost me $400 dollars. Since then I've had the same problem resulting in the solenoid being "fixed" three times (twice on passenger side and once on drivers), by two different places. After spending around $1200 trying to fix and having the idle issue come back I tried watching a few Youtube videos on what else could be done. When I unplug them the the engine idles just fine. So I thought "what if" I just leave them unplugged. I did that over 9 months ago and the engine has run fine for me, no rough idling, no noticeable loss of power. So what's the deal? Is it going to give out on me one day because they're unplugged? Any advice, thoughts are welcome.

 

You need to replace the phasers, chains, and get a Melling HV360 high flow oil pump.

When they fail they can also knock a hole in the valve cover.

Hate to break it to you... With what you've already spent, you could've had it half paid for to get the job done right the first time.

Good luck.

 

Manual F150
Thanks for your response. When the phasers, chains start to go do you have any warning? Right now the engine is running real smooth with no tics, knocks, or anything. The truck has 170,000 on it and is good body wise, transmission, drive train.

 

It will start to make noise. It may start sounding like a diesel at idle.

 

You've already experience the warning. Just haven't reached the point @ManualF150 mentioned "knock a hole in the valve cover".

Unplugging VCTs curing rough idle suggests idle oil pressure is inadequate to return Phasers to base (zero) retard. Frequently that is caused by chain guide debris clogging oil pump pickup screen.

A relatively inexpensive effort would be to drop your oil pan and check for pieces of guide junk in there.

 

If you haven't watched this video, you might want to. At about 45.11, he talks about the high failure rate of the chain tensioner gaskets that will reduce oil pressure to the valve train.

 

Thank you for the advice, I will try that!

 

I forgot to mention that the idle would only start to run rough when the engine was completely heated up. The first 10 minutes or so it always ran smooth. Thoughts?

 

The oil pressure drops when the oil gets hot and thins out. Have you tried thicker oil?

 

I've upped the viscosity a bit.

 

Try some 10W40