My Dad has a 2000 F250 V10 and have literally ran out of things to try to fix the pinging under a heavy load, basically it lts only when the torque converter is locked up and the engine is working hard. The spark plugs have been replaced, spark plugs have been retorqued, MAF sensor has been cleaned and checked with a scanner, the MAP wire grommet has been resealed, vacuum leaks have been checked including the PCV, the cat isn't problem anymore, all of the exhaust heat shield have been fixed for rattles and has no diagnostics codes with multiple scanners.

Unloaded the truck runs perfectly and while towing it does really well until the torque converter locks up... then the pinging starts, and I do know what that sounds like. It's definitely from the engine and the only thing I can think of at this point is the knock sensor.... am I missing something or is that my next step???

 

It's been a incredibly reliable truck and I don't want to destroy it.... 175k of hard *%#~ work and 17 years and it's still a darn nice truck!

 

Have you tried the Seafoam aerosol intake treatment? Someone on here was recently praising that as an answer to pinging.

 

have you checked your fuel pressure on the fuel rail? I had a problem with my 01. It would only ping under heavy throttle pulling a load. I also noticed the motor was lacking power above 3000 rpm. The motor would pull like crazy up to 3000 then fall on its face. ended up being a bad fuel pressure regulator on the back of the motor. it was a pain to replace but it was a night and day difference on how the motor ran.

 

Do one thing first. Run the gas down low, and put in some 93 octane. Does it make it go away or at least lessen it? You need to figure out if it's really detonation or something else.

I would also get a scanner/tuner and datalog the knock sensor info - I recall the the knock sensor logic can only retard the timing a total of 4 degrees, so if it's really bad, even with the knock sensor working, it can't back off far enough to make it go away.

 

Try the Seafoam spray treatment. Mine pinged, sometimes really bad and drove me nuts. I did all that you have done to no avail. I did the Seafoam last week and it is almost completely gone. I am going to do 1 more treatment this weekend and then every oil change. I was skeptical and thought I was wasting my 30 minutes of time and a few dollars for the can, but I was happily wronged! With that many miles on it, it won't hurt anyway.

 

I suspect the truck is running lean. Considering where you are from your fuel is probably contaminated with a lot of corn liquor (likely over 10%) which only makes matters worse.

 

I left out a couple parts that have been replaced in the past couple years, the O2 sensors,fuel pump and filter.

As far as the fuel pressure I haven't checked it and don't have a very good excuse as to why I haven't, other then I haven't suspected it because of how it's running, I have a nice tester so I will use it.

Sea-foam I might try, I have actually used it before in that manner but haven't really seen dramatic results using it that way.... other than my 89 Rangers old Engine, it's exhaust smoked for a good 20 minutes after. And that was while driving!

I can suggest trying a higher octane fuel and honestly can't say what it's burning currently, it's whatever is in our farm tanks, guessing it's probably 89 with 10% Ethanol. Whatever it is it works well in everything including my 06 V10 and 89 Ranger 2.9 with the timing bumped up to 13° vs 10° stock.

Running lean is a possibility I'm not going to write off just yet but from what I've seen looking at live data with my scanner it doesn't really lead me to believe that's the issue... i'm no expert at reading it and my memory isn't good enough to remember what it was saying, I might try it again and throw some numbers out for opinions.


The other day Dad had the new truck bug and was seriously shopping, after pricing newer trucks and thinking about how he uses it currently he looked at me and asked "Why in the heck should I spend that much on a truck that's going to do the same thing as the one I have, what do you think does it have a few more years?" I told him to do whatever he wanted and here we are. Lol, it is still a very nice truck and works hard.

 

I'm thinking Coil pack if related to RPM's and Engine Load. Do you keep spares around? Denso from Rock-auto is the same as Motorcraft yet half the price.

 

COP's causing pinging, I hadn't thought of that or heard of that before. It would be pretty easy to swap the eight from my Mustang over to Dads truck and see what it does though....

Despite everything you read on the Internet about COP's failing we have +/- 52 Ford COP's between us (some are newer) and I've only experienced two failing when the composite crossover coolant tube on the intake catastrophically failed on my Mustangs 4.6, it cooked and cracked the front two COP's.... it made an impressive amount of steam at -10°!!!!!

 

I don't know if would cause pinging, however if the spark/fire isn't their it could be an undetected misfire.

 

had this happen to my van brought it to the dealer a few years back had a miss they told me it had a cop and it needed new plugs. told them to go a head and change the plugs and the cop was covered under warranty. After we got it back it would ping only when I pulled my camper went up to higher octane it seemed to stop pinging. long story short they put the wrong plugs in it the next time I changed the plugs i found the different plugs in it. Drove my parts guy crazy trying to figure out the plugs he gave me the right ones but I was questioning him because of the first plug I pulled out. Ifigured it out after pulling number 10 plug out because they never changed it . After that it never pinged again.

 

That was my opinion also, there is no misfire issues so I very much don't suspect the cop's.

 

What was the wrong plug for the truck??? I honestly can't remember which plug we used when changing, it was visibly the same as what I took out and gapped to specs?
The pinging did kind of start when we catalytic converter plugged up because of multiple plug holes filling with water after bashing through extreme snowdrifts one winter, everything was replaced and thought it was fixed until dad mentioned it was pinging and running strangely quite a while later, that is when I found the MAF wire Grammont was dislocated from the hole on the airbox.... no idea how long it was out but it sucked a depressing amount of dirt through the engine, the intake behind the air cleaner was white with limestone dust .... really thought the engine was going to be toast at that point but it still runs good other than the towing ping and 2/3qt of oil per 4000mi now. (guess there was more to the story that I forgot about).

 

I haven't read all the reply's yet but your still in the diagnostic stage. I would remove vacuum from the fuel pressure regulator (watch the fuel trims decrease as you do so in all driving conditions ie; idle, load). And/Or create exhaust leaks before the O2 sensor by loosing up a manifold or flange on both banks so the computer tries to richin the A/F mix. Then listen for pinging again to give you an idea of the current fuel delivery psych.