I have 1998 F-150 with the 4.6. Last winter I had a light ping when in OD when going up a slight hill or a head wind, went away when spring arrived. The ping is back now that the weather is colder (Minnesota). 110,000 miles, new autolite PP plugs this summer, all else is maintained and in good shape. I plan to pull the EGR and see how stuff looks, I know it pulls in and out Ok ( pulled vacum on it at idle, engine dies out) but thought maybe ports are slightly plugged which would cause higher combustion chamber temps and may cause the slight ping. I thought I would change fuel filter( have only done once), maybe slighly plugged causing a light lean condition? Also I have the alternator light come on if you are on it hard, lights go dim, etc, untill rpm's come down(been that way for 2 years, I know, I need a new altenator). Anything else you guys can think of checking I would appreciate. Today I thought I would try a tank of higher octane fuel, but that is just a band-aid. My 97 Mustang GT never makes a sound on any old gas I run in, but granted I store it in the winter so it doesn't get run with "winter formulated gas." Thank You....

Spotty.....

 

Have you ever cleaned the MAF sensor?

 

I had always had a very light ping in cold weather on my 98 4.6, I would just run mid grade every second or third tank in the winter (so it was always a mix). In the last month things have gone nuts and the truck is nearly undrivable on regular unleaded, I've been running full premium until I get a chance to work on it. I too have heard MAF sensor, mine has never been cleaned in 104,000 miles. I will try cleaning it, but I may be replacing it. It's odd, my truck is semi-neglected, but I did the basics over the years and had no problems for 100,000 miles, it was great, now everything is going at once. If I had the money I'd be buying a new truck.

 

Yes, I clean the MAF twice a year, always use CRC specific Mass Air Flow sensor cleaner. I use that on all my vehicles yearly, a $6.00 can last for couple years.

Spotty..

 

I change my fuel filters every 10.000 miles. I figure its cheap ins.

 

you arent hurting anything changing the filter at 10,000 but Ford recommend every 30,000 yet many people put 100,000 on the original filter.

I do mine every 30K and never,ever had any problems.
just like servicing the tranny every 30K.

 

Replace the fuel filter with a high flow unit.

We've fixed pings with two trucks now.

The OEM pump is right on the cusp of not being efficient enough from the factory. When they get a few miles on them, they need to be replaced.

Put in a 190lph or 255lph unit, and solve that ping.

 

Where do you get these "high flow filters"

 

I had this same pinging problem pulling my 5000lb boat with my moms dodge with a gasser, turned out the air filter was dirty

 

I have a 2002 F-150 with the 4.6 and it started doing the same thing last fall. It pinged all winter but when the warmer weather came back the pinging stopped. Now that it's colder again the pinging is back. I tested the Intake Air Temp sensor and the ohms reading from cold to hot engine bay temp barely changed. It's supposed to be around 37 K ohms with a cold engine and 2 K ohms with a hot engine. Mine was 42 K ohms cold and 33 K ohms hot. I just picked up a new sensor from Ford Today and will replace it when the rain stops . I'll let you know if it works. At least it's easy to access. It's on the intake bellows after the MAF. I have a new Motorcraft a/f so it's not that. I have about 32,000 miles on the truck and the fuel filter is original, soon to be changed. I only get gas from high volume brand name stations so I doubt it's the gas.

Whimsey

 

Pardon me guys.

I meant to say high flow pump.

You can get a new fuel pump on ebay for under 100 shipped. Walboro makes the 255lph unit that I used.

 

use better gas

 

Thought I would update on what I found. Changed the fuel filter, tested the EGR again(OK), cleaned the throttle body interior, cleaned the air flow sensor, blew out air filter(is like new anyway),changed oil and filter( not relevent, but about due), did the seafoam deal thru brake booster line(let sit for 20 minutes). Went for a drive, as soon as it warmed up, that very light ping was back. Had a 1/4 tank of gas (87octane), pulled in Caseys bought 20 bucks of 89 octane (3 cents more per gallon). Drove the 10 miles home, not even a hint of a ping. So..... since this only shows up in the winter my conclusion is it's just this winter formulated gas here in Minnesota. I know I could have tried the 89 gas first but I wanted to be sure as many possible factors were correct. I hope Whimsey posts what he finds out on that Intake Air Temp. Sensor. The other day we had an unusually warm day ( 78 degrees) that light ping was still evident. Just for info. this is my truck I use in my business, it spends it's day hauling around garage doors and related parts, so that engine is always working. Considering how hard it works and how light the ping is, it's one heck of an engine. So I guess I'll stick with the 89 octane untill spring, it really made a huge difference. Thanks to everyone who helped out...........

Spotty..

 

Was on a recent trip to Nebraska and found this ping to be in a lot of automobiles, because of the octane rating on the fuel, when it is almost $3.00 a gallon or the cheap stuff a $2.89 which do you think the consumer would use, So with that in mind the ping is not go even if it is light, and even thought my 2 rides have been tested on the high octane over the low , it is the high that works best. Is't just another way the oil companys are sticking it to us.

 

I installed the new Intake Air Temp sensor today 11/11. Still have a 1/2 tank of 91 left. I'll wait till it's almost empty before I refill with 87. I was still pinging even with the 91, although no where near as bad. I'll let you know the results with the 87. So far it's not pinging at all with the 91 where it did ping lightly before I changed the sensor. I'll keep my fingers crossed.

Whimsey