Howdy everyone. I'm new here and hoping someone can help me figure this out. I used to work on my own trucks years ago but just recently gotten back into it, and boy oh boy they are not the same...lol...

Ok, here's the deal. In the past few weeks ive had to put a new alternator, new battery, replace the crank position sensor and a new set a plugs. I might add that ive changed a lot of plugs in my life and i have never seen anything like 3 of the ones i pulled out of this truck! if i can figure it out i'll post a pic of them on here. Anyway, I have noticed a noise now when im accelerating, back in my day i used to associate this noise with the engine being slightly out of time. its a rattling noise that i only hear on acceleration, once im at speed it goes away. I thought maybe it was an octane rattle, Ive ran 2 tanks of high octane through it and its still there. Oh, and i also put a bottle of injector cleaner in the tank a couple weeks ago.

Any ideas what this might be? and if its timing, how do i set the timing on this thing...I guess I should mention that its a 2003 F150 4.2 ltr and just over 100,000 miles. Until the past few weeks ive had no issues out of this truck at all. Any and all help will be greatly appreciated....

Thanks....Mike

 

Timing cannot be set, it's completely under computer control. You don't have a distributor, you have a coil pack that's triggered by the PCM.

You may be carboned up - go get a BG or Motorvac intake cleaning job done.

What brand of plugs did you use?

 

If the higher octane is not helping, another potential cause of pinging is overheating / cooling system not working properly.

FWIW, over the years, many folks (me included) have had problems with Bosch plugs in the 4.2 V6.

 

I use nothing but the OEM Motorcrafts in mine, and I don't even ping on 85 octane mountain gas. I do get a BG job at each plug change.

 

I used Motocraft Platinum plugs....I should also mention that at the same time as i did all this other work i also replaced the ignition coil pack.

 

Cooling system is fine, the gauge is never more than 1/2 way, and the reservoir is full of coolant. I have ran high octane gas through it, the pinging is still there, but only on acceleration, once up to speed it all goes away. I must say that changing the ignition coil pack and putting new plugs in it has made a hell of a difference in the power and fuel mileage...now if i can just figure out this pinging!!

 

Changing the plugs was surprisingly easy on this one, i had way more difficulty changing them on the chevys ive owned...lol...

 

Do U have a code ? It may be a vacuum leak.

 

I have encountered small head gasket leaks that cause a labor knock...I would suppose an intake gasket could cause this also. Not overly familiar with Fords but on a Chevy the knock sensor can cause a labor knock. Your problem could be a number of things, including a camshaft position sensor. Hard to say without a code.