My 2010 Mustang GT 4.6L automatic with 97k miles on it has a noise coming from the drivers side valve cover.

The noise sounds to me like all of the other typical cam phaser noises; a ticking sound about once per engine revolution - getting faster when the engine is accelerated but not louder.

Because of the usual failures of the VVT system, I thought I'd replace some parts that normally go out on those things:

Replaced: Driver and passenger side Cam Timing Phasers, Driver and passenger side VVT Solenoids, Both timing chains, crank sprocket, and all plastic timing guides and tensioners, All spark plugs.

It still has the same noise. I probably should have went ahead and taken the heads off, but didn't.

The VVT system while driving still seems to 'pulsate' and causes the engine to ping at times. No engine codes are being thrown.

Engine oil and filters were changed and the correct viscosity oil and Motorcraft filter is used.

Could the oil pressure just not be high enough? Should I have replaced the oil pump too?

Or is it just time to take the heads off? I did not check compression though I probably should have - and checked the oil pressure? Or did a valve possibly get burned?

  • 1
    You need to localize the noise better by using an automotive stethoscope. If you are still hearing the noise after all the parts you've thrown at it, you need to narrow it down further or you'll just be spending more $$ without solving anything. Jan 31, 2017 at 21:39
  • 1
    Checking oil pressure and compression are excellent ideas and far less time consuming than removing a head. I'd start there and see if either show you a smoking gun.
    – atraudes
    Feb 1, 2017 at 0:29

2 Answers 2


How about substituting one quart of motor oil with Marvel Mystery Oil? You may have a little varnish somewhere on a valve lifter, valve stem, oil pump, etc.

  • I use it with fresh synthetic oil, since it works better with the detergents in fresh motor oil. It is safe to mix with any motor oil. You can leave it in the crankcase until the next oil change, just be sure to change it before 3k miles. It quiets lifters usually within 15 minutes of highway usage, but can take weeks longer if there are stubborn deposits. Guys who have not used it love to call it "snake oil," but it's worked for me on multiple engines and has been around for 100 years! At $7 per bottle, what do you really have to lose?
    – Carguy
    Feb 5, 2017 at 6:48
  • 2
    @juhist MMO is mostly plain old mineral oil in expensive package. There is no evidence that it helps anything. Source: en.wikipedia.org/wiki/Marvel_Mystery_Oil Mar 11, 2017 at 18:24
  • The Wikipedia entry offers no evidence against the effectiveness of MMO. The singular case of the airplane crash led the NTSB to merely guess at the cause, without directly implicating it.
    – Carguy
    Mar 13, 2017 at 14:42

I know this question is old, but I thought I'd provide some feedback for future.

Cam phasers make noise due to a lack of oil pressure in two cases:

  • The inner rotating piece connected to the cam shaft contacts the static* outer piece connected to the sprocket/pulley. This will be loud especially at high engine speeds. This means the phaser is getting no oil, which means it needs to be replaced.
  • The rotating piece (rotor) is in it's locked position and is rattling at startup, and then the sound disappears. This will typically be a much more quiet and higher frequency sound, which will disappear with engine speed.
  • If the noise remains the same intensity with increased engine speed, it is not the phaser. It should either become quiet, or deafeningly loud.
  • Always try cleaning the oil control valve (OCV) first, it typically has inlet and maybe outlet screens which can become clogged; a little splash of gasoline and a q-tip work well to remove debris. The OCV is usually easy to get at, and might save you some time and money.
  • Don't open a cam phaser. They have an internal set lash which allows them to lock on shutdown, if you open it, it will loose this lash and most likely fail to relock.

Good luck and happy motoring

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .