Update on my pinging 06: I ran a can of Chemtool through the van and the pinging under load is gone. I'll see how long it takes to return....

Jack

 

It would not be your intake butterfly shuttering. think about it, if they were occalliting that fast, how would the engine be performing? I would think that it would feel like a misfire. What you have is a lean condition, possibly caused by the maf meter, or the calibration level of the software in the computor. Another thing could be the fuel, in general. Most of the fuel we process today comes from a high sulfur content.

 

Guys,

I have the exact same problem with my '04 F150 Heritage 4.2l. I get a pinging sound between 65 mph up under acceleration or climbing hills. It was an intermittent problem and didn't do it all the time. I tried different octane and it didn't make a difference. The check engine light came on and I took it to a dealer who said it needs IMRC bushings. I still haven't got it fixed because they didn't have the parts in stock, and wanted $1000 to fix this. I tried different brands of fuel, switching from Chevron to Shell, and thought I had cured the problem. Then, while driving on the highway with no problems, I "gunned" it to pass a car. It started pinging again and went back to it's old ways. So now the problem is back again after I pushed the accelerator pedal further than normal. With what was written here, what I have been through, it leads me to believe the IMRC valves are loose somehow, and I activated them when I accelerated hard to leave them in a loose position, and as soon as I spend $1000 to fix it, the problem will go away. So far, after 50,000 miles, this is the only problem I have had with this truck, and from what I hear, those IMRC bushings are a weak link on the 4.2L Ford motor.

 

Update...Tossing another wrench in this fire. I went to bring the van in to the the new service manager just after the New Year. Very cold morning just above 20 degrees. Got motor warm and could not simulate the noise in the same location as previously. The noise has been heard at tempatures over50 but who runs around with the windows down below 40?? It is mine and the new service managers opion that it is most likely a lean condition in the motor due to the programming (which will most likely not change, and yes the PCM was flashed this summer with the latest updates). The reasoning is that the only changes were air temp and of course fuel blend (winter vs summer), and that this only happens during peak performance (ie peak torque 3600 Peak horsepower 4200), with the understanding that the PCM is tweeking every once of power with the minimualist of emissions.

 

Your over 50° F temp just clicked in my head. I believe that theACT isn't used below 50° F.You could have a faulty ACT in your MAF since the problem doesn't exist below the 50° F.

 

That would tend to setoff the CEL???

 

2007 F150,4.2V6,18K miles
Several weeks ago my truck started pinging very bad,esp. at upper rpms.I took it into my local Ford dealer and they diagnosed it as a bad EGR valve.They replaced it and reflashed the computer.Well,that didn't fix it.Back to the dealer it went.This time they wanted to replace the IMRC bushings.Upon removal of the upper plenum to get to the bushings the tech found anexcessive amount of oil and carbon lining the lower intake plenum walls.The spark plugs were oily and carboned too.Also,the pcv valve was dripping with oil.After decarboning the intakes and upper cylinders (4 times),replacing the plugs,replacing the MAF sensor,replacing the pcv valve and hoses,they said it was fixed.For about 3 days afterwards,it was ok; then this past week it started pinging again! This time the tech and I went for a ride with his laptop plugged into my computer to record whatwas happening when the enginestarted pinging.Ford engineering will go over the techs recordings and then give further instructions on what to do next,if anything! [sm=violin.gif]

 

Wow, so it's 12 years later, has there been any progress with this for anyone?

I have a 2001 4.2L V6 with 170k miles, that also pings/knocks when accelerating on the freeway ~65-75mph.

I have noticed that premium gas helps drastically, and I don't get any codes.

I use to only drive about 7k miles a year to the store and back, so using premium didn't matter as much, and I rarely hit any speed above 45mph. But now I'm having to drive it more and would like to get it fixed before I do any damage.