I have had a constant problem with pinging. The only time it doesn't knock is if it is idling or floored. Driving around town at part throttle causes it and so does maintaining speed on the interstate. So far, the throttle body has been cleaned, the upper intake has been cleaned and the little tiny filament in the mass air sensor has been swabbed with alcohol as well. It stops knocking if I burn premium fuel, but it's my company car and since they pay for the gas they say no premium! The truck is at Lincoln now for some simple stuff so they are going to re-program the ECU. Apparently they can do it so at part throttle, the timing will retard, but it is not affected at WOT. They said if that doesn't work, they want to replace the mass air sensor. WHY? Is it possible that it is reading the incoming air wrong? I don't know. That's why I'm asking. If I do end up replacing it, can't I install an aftermarket piece with the added benefit of more power for about the same price?

Any help would be greatly appreciated!

 

I went through this with my truck. If cleaning the MAF didn't fix it then it will have to be replaced. The wire in there burns red hot while driving and will turn the oil that flecks off the K&N into a black carbon like substance (like on your stove burners) that doesn't come offd when cleaned. Try replacing it. Ask around about a High Perf MAF.

 

I have found on fordranger.com that the guys that use the K&N air filter have had the oil from the filter contaminate the MAF sensor. Some tried another filter, some went back to a stock filter. Me, I would find a different type or contact K&N and explain the problem. Maybe they could provide some technical help.
As far as the knocking engine, what happens when you use a stock filter in the air box?
The other thing is the E.G.R. valve. If the valve is not coming on as it should be, the combustion chambers are running hotter then they have to be, which then causes the fuel to ignite before the spark powered flame front can fire the mixture.
Also this engine may have a knock sensor on it, that may not be working or the computer may not recognize the signal coming in.
Flashing the computer may help, but I would make sure the knock sensor and the E.G. R. are working under load.
Mike C.

 

Had the same problem with my 1997 F-150 with 4.6. It took a lot of money to fix the problem. Had to get new MAF Sensor, new plugs, 1 new coil, throttle body cleaning, and have cylinders cleaned. Problem was compounded by the use of premium gas to try and stop the pinging. About $1100.00 worth of stuff to stop pinging.

 

ExpyGator,

Got the same problem on my 99 F150 w/4.6L Auto. I've had it in the dealer 3 times now, with no success. First time they said run 89 octane. Did that, no help. Next time they said the MAF sensor was out of spec. They replaced that, no help. Third time, they said "yep, we hear it, but everything is in spec"...basically they ain't doing nothing about it.

Have you noticed if this only happens when the air temp is hot...say above 95 degrees? Mine tends to do just fine when it is below 95 degrees, but when it is hot outside, the engine sounds like a diesel.

Yankee7985, what finally cured your problem? Did you have all that you listed done at one time?

I'm taking my truck to another dealer on Thursday. I'll let you all know how it turns out.

 

Thanks to all who replied. I know the knock sensor works because it doesn't ping when floored. It does knock worse when it's hot outside. Got the truck back from dealer today. They re-prgrammed the ECU. Taking a trip tomorrow, hopefully I will be pleased with the results. They did indicate that if this did not fix it, I would need a new MAF sensor. Thanks agains for the replies.

 

SRB 150,
I had all the work done at once, and it made a big difference. I occasionally notice a slight ping when I am towing my 20' Javelin boat, with to O/D off, and turning about 2700 RPM's. I just have not had time to return to the shop. The shop said that these newer, lower compression engines do not burn the fuel as well as the older engines, and using the higher octane fuels leaves a lot of carbon inside the cylinders.

 

Well, the problem of the pinging at light acceleration continues. I just got my truck back from another dealer in Oracle AZ. At least this dealer admitted there was a problem and attempted a fix. I can't hardly make anything out on the service report. Maybe some of you all can. Here's what it says...

VERIFIED CONCERN EEC TEST NO DTC PRESENT PID MONITOR ROAD TEST BARO FREQUENCE LOW. REPLACED MASS AIR FLOW SENSOR REST KAM TEST FUEL PRESSURE ADJUST OCTANE LEVEL REPROGRAM PCM EEC TEST ALL OK.

Think it says they basically replaced the MAF sensor and reprogrammed the computer. Didn't fix the problem. On the drive back the engine was pinging so badly I stopped and put 93 octane in it to stop or at least squelch the pinging.

I'm at my limit with this. The next call is to the zone rep.

 

The problem with the knocking is if you have aftermarket mass air flow in or whether you don't, it has to be recalibrated to match whatever lb injectors you have if you have the stock 19 lb injectors it has to be recalibrated to the new mass air or even the factory mass air, this is a very extremely common problem when people replace the mass air flow sensor and keep the factory 19 lb injectors, or even if you change them to a difference lb like 24 lb or 30 lb , the best fix is having superchips recalibrate it by just giving them all your information and have them burn a chip , which will benefit you in the long run with any mods you have done or plan on doing but do them first them have it recalibrated and burn the chip.

 

Flippinford,

Everything is stock on my truck. What is it that your saying must be recalibrated? The MAF sensor or the computer program? Seems to me that Ford should already account for the tolerance in their MAF sensors in their computer program, otherwise they'd be custom reprogramming every vehicle being manufactured.

This problem of mine is pretty crazy, I've gone through 2 MAF sensors in 6 months (under warranty). I think there is something else causing this problem. Like someone else said on another post...the mechanics are afraid to do anything to the engines without an error code.

 

The only other problem you can account your problems to is the IAC or IAT or the mass air flow and fuel injectors and the octane of gas, i've spent a ton of money with the same problem and illiminated it by relocating my IAT and making sure the IAC is good and having a custom chip burn't to recalibrate the mass air flow sensor to match the fuel injectors, factory stuff doesn't always work that's why you keep having the trouble, if the factory warranty people was able to fix it you still wouldn't be having the problem, your engine is running to lean and needs more fuel, that cause a ping , like low octane fuel, mass air flow sensors are sensitive and even though you buy ten of them not one will be the same and superchips is the only people, i've ever known that has been able to eliminate the problem when ford can't.

 

Mine seems to act up when it is cool outside below 60*. The is several post about this under post "98' 4.6 pings only when air temp is low?". Seems mine only did it one or two nights when temps were around 55* and under load. I could only make it ping when I matted the pedal and the RPM's hit about 4200. IN my mind that tells me that the air is going to be dense and the computer is retarding the timing too much and cuasing a lean mixture. I have since ran a bottle oc Chevron cleaner and a tank of 89 and have to yet seen anymore pinging problems. I guess I will have to wait for another night below 55 just to see for sure. If so I will wait for a 3 day cold front to move in, pull the cables to rest PCM and let the PCM relearn it's timing tables when it's cool outside to see if it helps.