Well... after reading many many posts about the PING I started to do something about mine.

After Cleaning MAF, Sea foam in Vac line and tank, Cleaning IAC and EGR (best I could), I still have a ping at highway speeds under light loads.
WAY BETTER than before, (used to be at all light loads).
THANKS to all.

But What can I do now?
On 91 Octane it does NOT do it, but when I go back to 87 it does, at light loads at Highway speeds.

I've read about people asking if it does it at all gasoline grades, but never figured out why they asked.

Any help>?

 

What year is the Ex? Mine is a 94, and here's the other things that I did that COMPLETLY fixed the ping problem.

Torque the lower intake manifold bolts. They can work lose and cause a slight vacum leak. Check all of the vacum hoses for cracks and dry rot. Replace the fuel filter. If it's clogged at all, it will cause it to run lean. Pull the codes - an EGR or DPFE problem could also cause a lean condition.

Good luck.

 

It's a 1994.

I did check the intake bolts, the ones I could get at...think I could not reach 1 or 2.

Fuel filter was replace about a month ago along with the pump.

Any thing else...it ONLY does it on 87 octane???

 

The octane rating of gasoline is a measure of how "difficult" it is to get gasoline to burn. The higher the number, the more difficult it is to ignite the mixture, the more resistant to pre-ignition (aka spark knock or ping) the gasoline is.
You've pretty much covered the common causes of engine ping. I guess you get to try some of the uncommon causes.
1st: check for vacuum leaks other than the lower intake manifold bolts. I've heard of the air intake tube developing cracks or separating at the seam. If I'm not real careful with mine, the seals where the intake tube meets the MAF don't like to seat properly. Check all the vacuum lines. I have heard of a leak through the transmission vacuum modulator causing ping. In short, you have the tedious task of assuring yourself that there is no unmetered air entering the intake manifold.
2nd) dirty injectors have been known to cause ping by not feeding the correct amount of fuel into the cylinders.
3rd) Check the ECT and make sure it's reading is correct. If the temperature reading from the ECT is too high, the computer will lean out the engine and could cause it to ping.
4th) As for tightening the lower intake manifold bolts, usually that works. On occasion, the gasket is too far gone, and the only way to fix it is to remove it all and replace the gasket.
There's a few things to work on.

 

Thanks mrshorty...

Any value to me changing my plugs out to the recommended motorcraft from the existing platnum (Bosch or Champion) I am running now? If so what Motorcraft are recommended for the 94 V6 ??

Being it was Pinging only at low octane fuels, I was hesistant to doing the plugs.....

 

Hey,

You might try adding some engine oil additive. I have had trouble with my 93 and lifter tap. Added some PTFE from Advance once every two or so oil changes and the tap has gone away. I had to use 93 prior to this and now have no problem on 87. Might help some.

Eric

 

I don't know if it will help or not to replace the plugs. I know when I tried a set of Splitfires, they caused my engine to ping like it was going out of style. Installed the standard copper core plugs (your '94 would have likely had platinum plugs fromt the factory instead) and it ran better. As for Motorcraft part numbers, you can try looking them up at www.motorcraft.com