Hi guys I'm new here. I'm looking for some answers to my pining problem. Heres what I have. Its a 2001 f250 4x4 super crew short bed 124,000 miles. I've owned the truck for a year and a half. Its stock except for a flowmaster(came that way) It had 114,000 on it when I purchased it. Its pinged since I've owned it. I used the truck for towing mostly. Here is what I've done. New plugs boots and wire thing. New fuel filter topend flush by the dealer twice. ECU flash and full diagnostic 91 octane with octain boosterand cleaned MAF sensor. I just passed smog on the 29th of september with flying colors hardly read anything. It sounds like someones rattling a tin can of nuts and bolts under the hood. Its only while I tow my 26' toyhauler about 10000 poundsfully loaded. It starts when it down shifts from OD to third around 3000 rpms as the rpms goes up it gets louder and farther apart( I tow alot so I have had a chance to play with my accelerator to hear exactly what it does) and when I have to get into second gear going up steep grades like the hill coming out of Camarillo in California forget it I have to use only half throttle cuz I fear it will explode because of how violent the noise gets.I also dont have any loss of power just loud pinging. Every dealer I take it to cannot figure it out. Since my truck doesnt have an egr system could it be the knock sensor. I havent had the check engine light come on at all and no codes are stored. I just want to figure this out. Thanks for any info.

 

Have you inspected for some of the more common problems that sound like pinging yet?

Loose heatshield(s) on exhaust pipe(s).

Loose inspection plate on the front of the tranny.

Broken exhaust studs.

 

It absolutely is pinging without a doubt. The exhaust all checked out no rattles or missing bolts or studs. Plus if it was exhaust it would make noise on a daily basis not just when I tow and at certain rpms.

 

It's very likely it's the hideous PCM programming. Heavy loads and closed loop operation are bad ju-ju for towing.
JL

 

We've heard so many of these complaints, it's not funny.

I'd suggest changing the knock sensor - they can go bad without throwing a code. But I hate to throw money at something without KNOWING it's bad.

Someone suggested getting it hooked up to diagnostics so that the knock sensor can be monitored and whacking the knock sensor with a brookstick.

But depending on the cost of the knock sensor, it might be worth just changing it instead of paying for the diagnostics.

 

Problem is...that's a 4-5 hour job at the minimum. It's under the intake manifold at the bottom of the "vee" in the block. In my past experience with knock sensor failures,there's knocking all the time under all load situations with moderate the heavy throttle,not just when towing a load.
JL

 

Do you think it work be workable if you remove the alternator and upper plenium and the lower plenium possibly rotate it in the valley(if possible) or move it back or slide it out the front?

With the vehicals you have changed the knock sensors on what were the symtoms the owners explained to you?

 

No can do-the intake MUST come off. I didn't change them-it's too much work/hassle. I simply disabled the knock sensor programming via PCM retune to prevent the knocking.
JL

 

There have been people (at least two) that changed the knock sensor without removing the intake. I have absolutely no idea how though.

As for only pinging under load, is that on the V10? The V10 is already horrible hobbled in terms of timing anyway, under load would be about the only time it would even get NEAR to pinging once it's nice and hot.

 

Here is my experience with pinging and my V10. The only time it does it is pulling a load at or close to sea level and it gets a lot worse when we are on the west coast. When we get back to the Midwest it goes away in fact all we have to do fill up with fuel half way through Nevada and it goes away. It's the crap gas that you have on the west coast and Alaska. This summer the hole time we were in Alaska we had terrible ping (some of the worst I have ever had) and it went away after we filled up in Canada and returned when we filled up in Washington. Last time (06) we where in Florida we had some ping but nothing like the west coast. Also when out west it doesn't go away in the higher altitudes like it should until I get a better quality gas. When we leave the Oregon coast in the spring I fully expect to have terrible ping until we get half way through Nevada just like every other time we have made this trip. Also our truck was purchased in Oregon new with California emissions. I think you can change parts until you are blue in the face and the ping will still be there.

Denny

 

I don't know how they ever changed it with the intake in place.probably took them 4X as long than if they would have removed the intake if they did indeed change the sensor with the intake in place.
If the knock sensor is not reporting knock,the PCM programming advances the timing until it sees knock,or hit the table's limit for advance. With a bad sensor,you get knock since the PCM cannot "see" the knock and retard the timing appropriately..
JL

 

Can the knock sensor be easily unplugged to see if the pinging gets a lot worse. That would tell you if it is working or not...right?

Mine went away after I replaced the fuel filter and cleaned the MAF. I see you have already done that. The only thing I did different was that I disconnected the battery during the FF/MAF clean. So it was disconnected for an hour or 2.

No more pinging on 87 octane. I put in 89 octane to tow because I get about 1.5 mpg better mileage. I think when I use 87 to tow with, it retards the timing a lot to keep from pinging, so mpg suffers.

 

That I honestly do not know. The PCM might know if it's missing,and avoid advancing the timing in that case.
JL

 

Knocking is hard to diagnose on the west coast, with the changing of gas around from season to season. First if you think something is wrong, I would suggest boosting the octane to test the gas, that has worked for me before, on my 2000 E-450 V-10 Motor Home with 80K.
But the last time, (like now) when it has a vary slight ping, I am unable to get it to go away with adding a half a tank of premium, or several bottles of octane boost, so now i'm not sure what it is.
Its vary light, and only around 2500 RPM and up and only under light throttle, if I step on it harder it goes away, so this makes me wonder if its even pre ignition.
Under conditions that it should knock, like heavy load, low RPMs, and heavy throttle it doesn't ping.
So now I'm confused.

 

As you lean on the throttle,the PCM retard timing since load is increased. At steady state cruising,the PCM uses input from the knock sensor to advance the timing if no knock is detected. With a bad knock sensor,the PCM can't see the knock,keeps adding timing and you get more spark knock.
JL