Do you really drive a van in the 3600-4200 RPM range that often? If the ping is not heavy, and not present under 99% of daily driving condition, I wouldn't wory too much about it. Easy fix, keep your RPMs down.

 

Jakers, I believe when al is said and done it will be a weird quirk to the 4.2L V6 in the Freestar. As another psoted he had heard of the same issue, possibly had it in his, and I haveconfirmed other forums have discussed this issue. However, I have not found anyone that has determined the cause. The one thing I did come across is Helmholtz Resonance in relation to VLIM intakes http://en.wikipedia.org/wiki/Variabl...ntake_Manifold, it may be that it is a resonant sound due to the intake. In addition, my hope is that if someone else comes across the issue they can add their knowledge and expereinces.

 

94BLK5.0, You are correct, I do not usually utilize the power curve for the engine (ie peak torque 3650 and peak Hp 4250) and I am not over concerned with a major mechanical issue resulting from the sound. However,it is the wife's car, it carries my kids, and it had best bring them home safely. So with that I take it as my personal responsibility to make sure that the van provides reliable transport to the best of my ability, or I get rid of it...................

 

2 TSBs as of mid July 2007 dealing with the intake runner that tunes the intake. The basic I have gotten from my dealer at this time is:
1. Possible moisture entered PCM and or PCM connector,ping or knocking is one of the possible symptons of this.
2. Plastic bushings worn or damaged on runners orservo causing runners tovibrate.
I am scheduled to bring the van in the8/27/07. I will post what if any was found.

 

The lastest I have from the head of service at my dealer is that Ford is saying it maybe "Normal". He does not like that response and was/is looking for an 06 with a 4.2 to test it for the noise. I am also trying to get a freind of mines 06 mercury to run laps with for the same sound. If I ever get a final resolution I will post it. I apprecate everyones in put and help.
Thanks

 

I had a similar sound with my 2004 freestar when I first got it and I also had it with an earlier 4.0L in a ranger. This problem is just carbon build up in the combustion chamber. If this is your wife's van, she probably doesn't run it very hard, ie above 3500 rpm. This aids in the production of carbon. The fix for my van was to take it on the highway and run it in 3rd gear and accelerate hard, ie on the floor, and then let off and accelerate hard again, do this about 6-10 times and you should hear the noise get less. You need to heatup the combustion chamber to burn off the deposited carbon. The higher the revs the better and the more load you can put on the engine the better, ie up a hill. Afterdoing this with my Freestar, thepinking noise is completely goneunder allloads and rpms. The exactsame thing worked for my old 4.0 L engine. Worth a try...[8D]

 

I would assume that a five hour tow with an 1800lb trailer running at 3000rpmwith on and off ramp and various starts/accelerations pushing the revs between 4 and 5k would most likely clear carbon buildup of the nature you reference? Additionally, I have picked up on this noise since the van had 4000 miles or less. In addition, I havea freind witha mercury that produces the same noise under tha same conditions................

 

Just out of curiosity, have you tried going to a higher octane fuel to see if the ping goes away? It's possible that the PCM programming isn't correct for the timing advance at higher RPMs. It's also possible that the MAF isn't properly calibrated from the MFG causing it to readless air flow than actual causing a LEAN condition at the higher RPMs. I have a 2004 without the problem and you have a 2006 with the problem. But then again, I also run copper core plugs gapped at .48 in conjuction with water injection.

 

Have you checked the metal rods that connect the IMRC motor to the runners in the intake manifold? Have seen a couple of newer F-150's with the 4.2L with this concern, the rods aren't connected to the runners or electric motor causing the ping condition.

 

BRETM; Yes, actually there is a TSB for premature failure of the plastic bushing on the actuator links.

U.C.S.- The ECM was reflashed as one of the 1st steps, to provide the most upto date program and specs to the ECM......