So far, I've had medium gas in there since I made the original post and the pinging sound seems better. Does this make sense?
Also, what is a MAF sensor, becasue I'll check that out also.

 

The easiest way to identify the MAF is to take out the air filter and look inside the hole where you'll see something that looks like a lamp filament. That's the MAF and I think it's made out of platinum. Don't touch it. I think finger oils will cause it to fail.

Some people say you should clean it with a Q-tip soaked with Windex. Most say don't spray it with anything. Some say you can spray it with Brakleen. I really don't know what's best, but most seem to stick with the Q-tip and Windex.

 

defacto, the windex/q-tip method works. You just have to be very careful. After I did this last year, I went back to regular fuel.

 

Of all the things, I tell ya, if this is the fix, I'm gonna crack up. Q-tip and Windex, figures eh? I'm gonna clean it regardless. Sounds like something that should be done every year or so. Again, figures, I don't see this in my manual anywhere, do you?

 

Yes

 

skidmarkracing:

Thanks for the very detailed response, you're a big help to all of us here on f-150 online.

 

I haven't done this, but plan to try on our '90 Legacy...

Replacing the oxygen sensors may eliminate the pinging, since they are sending incorrect information to the computer.

If anyone has done this, I would love to hear more !!

 

I have the same problem so I will also try to clean my MAF and see if this helps. I used a bottle of injector cleaner and that seemed to help a little but the ping is still there but not as bad. I have a 4.6L with 33,000 killometers. 1999.
Cheers

 

Yankee


i'm going w/ yankee on this one... he knows his **** about ford computers and how the motors in todays cars are tuned...

ford does advance timing under load to improve low end torque, this causes a major increase in your engine,s spark plug temp, and exaust valve temps, (these are your hot spots)

cooler plugs will solve the problem... and he is also right about the carbon build up, there is no magic in a bottle, but there is in your tool box, it's called a putty knife, and you use it to scrape the carbon off your pistons,

oh, and what will cause carbon build up in your motor, you gessed it... (incorrect combustion temp) usually too cold (the other extreme) incomplete burn... fuel collects on your piston hat and valves and clowly burns forming carbon build up...

the stuff the dealers use is injector cleaner, not piston hat and valve cleaner, for that you got nothin but good old elbow grease..

take it from some one who knows, i have been building motors for a long time in an auto machine shop now and know the tell all signs..

i have scraped my fair share of pistons too..., and cut valves,

 

Bull to all your theories. If it's a carbon build up, then why do I have a spark knock on a 2001 5.4 with 8K?? Never used less than 93 octane since I bought it. Ford has changed the cats with no results. The Tech has advised me now to burn a tank of 89 octane. Says the truck is designed to burn 87 most efficiently and that using a 93 octane contributes to carbon build-up. How can this be when I thought the a higher grade of fuel burnt cleaner??????? Anyway, have been told if the lesser octane does not stop the pinging then they will need to reprogram the computer. I've about had it with this Ford. It's been in the shop once a week for the last four weeks for this same problem and they can't seem to fix it.

 

Be careful with the fuel additives, guys. They help out now and then, but are bad for your plugs in the long run. Down and dirty; the additives will cause ecxessive wear on the spark plug electrodes. Sometimes, it will even put a ash type buildup on the electrodes. Basically, you just ruined your plugs. Next time you change your plugs, look for the copper/light brown color on the ceramic portion of your plugs. This is due to fuel additives.

I would maybe use a good fuel additive once a year at the most, and run the same brand fuel. Find one that your truck runs best on, and stick to it. There are additives and detergants in the fuel already.

As far as the ping problem, you may try a diffent brand of fuel. This helped me out once... Also, if you are running the same gas in your truck on a regular basis, there could be contaminents in the fuel. Water in the fuel, will cause your engine to ping, under a load or not. Also, you may need to have the ping sensor changed.

I didn't read all the posts, just scanned thru them. If someone has mentioned these items, please forgive me.

Best Of Luck...
R1968

 

Okay, this may sound like a stupid question but what does pinging sound like? Does it sound like the word - a high pitched sound like thumping a crystal glass or is it more of a knock/clack, like what a lifter sounds like when there isn't enough oil pressure??
Is it something barely audible or is it a sound that resonates and enters the cab??
Finally does it only happen under load or is it common just at idle?

 

Tough to describe. maybe like a chain dragging on the pavement. Mine's only under acceleration. 1500 to 2000 rpm's when it's the loudest. No noise in idle.

 

The ECM uses a spark/Knock /ping sensor under the intake to provide a closed loop feedback control signal to limit spark advance. I believe sensor sends a discrete on off signal to the ECM so if the device is faulty the engine will ping. Note that this fault will not necessarily report a service engine code. replace the knock sensor and save your engine.

With respect to dosing the engine with additives and possibly poisoning your cats, I suggest an exhaust gas analysis, If the NOx is higher than baseline this could indicate too much spark advance. As for carbon buildup, it does not occur in a properly running enging, carbon buildup implies incomplete combustion which would flame your cats, you would also report codes from pre and post O2 sensors. The deposits that occur are usually ash and metal alkaly salts Unless your burning a quart every 500 its definitely not carbon.

Jazzpro::

 

Ok, well....so that's all ther is to it eh? jeez, what's wrong with you guys, it's such a simple question and answer Kidding. I tell ya, I'm more confused now than I was when I posted my question. So finally, what I guess is the most important part of the question, does pinging (or whatever the hell is causing it) cause damage?