Any fault in the egr system would be detected by the DPFE sensor and would display a DTC in the pcm.
any undetected air being input would cause the O2 sensors to cause(PCM) go rich not lean on the fuel trims.

Remeber that there are alot of sensors that contribute to the proper working system
Maf,IAT,CKP,TP,ECT ,O2 that feed the PCM
Which then control outputs( timing ,fuel injector pulse width,trans shift points)

Rich

 

I never ran the engine with the knock sensor disconnected electrically. I will do that and see if there is a fault indicated.

I have higher octane fuel in the tank now. I will wait to reset the PCM after I re-fuel with 87 otane fuel so it will re-learn with 87 octane fuel.

I run the truck mostly 0 to 500 ft elevation. Occaisionally up to 4000 ft elevation. It pinged heavily pulling a trailer over a 4000 ft mountain pass with 92 octane fuel. That was the only time I had a significant ping on 92 octane fuel.

I have only used Chevron gas.

I cleaned the MAF sensor twice in the past few months.

All of the spark plugs were a light tan color. No unusual appearance.

I don't have access to a scanner. I will see if I can find someone with scanner. What type of scanner would I look for?

 

1. ping is the first stage you hear with ignition timing a bit to far advanced. Sounds like marbles in a tin can.
2. knock is the second more severe stage and sounds like some one hitting the block with a big hammer. This stage is what the knock sensor is supposed to detect because it can be engine damaging. Breaks rings/ pistons/ hard on bearing etc.
3. at 4000' elevation, the air density gets thinner. This has the same effect as lowering the fuel octane as it makes combustion/flame speed increase, so ignition timing will be crtical if the system can not adjust in the retard direction, enough.
4. does the gas you use have ethonal in it? This never helps even though it may have higher octane rating because the OX sensor detect the extra oxygen. The ox sensors are calibrated for straight gas and donnot handle the alky in quite the the same manner for adjusted A/F ratios.
5. scanners are near $300 up for a unit to look at PIDs in depth. A reader will not do any of this.
Work closely with the EGR system because it can generate your problems without codes because the system is not perfect and has parts tolerences to detection of faults. Some tolerences stack up to be to sensitive. The oppisite is to lose and a lot of things happen without being detected quick enough.
6. be awhere that every time you power down the PCM you lose the accumulated table adjustments to driving and faults. These do not get rebuilt at a fast rate and usually takes several drive cycles to complete all the routine tests involved as well as shift the basic tables. This, in it'self can cause you to see all kinds of results over short time periods and cause confusion.
Everybody would like to think these trucks and cars should be simple to fix by code etc but it's often not the case.
The one who chases a fault from a foundation of knowledge and tools, is the winner. Everyone else either has to have luck or never solves the problems.

On gas quality: I recently tanked up in the state of N.J. with Gulf 87. Never even got to 300 miles to the tank.
Retanked with Citgo 87 in Pa. and still running on that gas after taking the same trip the next day.
The gas in N.J. is spiked with ethonal by state mandate and runs awful for mileage.
PA gas has no such adds. I have repeated this 'test' times to see what happens and it's the same everytime.
I will say however that CITGO uses a patanted UNACAL formula with at least 16 additives and it's about the best running gas you can buy dispite the association with a south american dictator. It's formulated here and not by some other enity.
I know it leaves a bad taste with some people but we have to be practical until some other oil company steps up and does as well for performance and cost.
I have given lots of explaination, background and example. There are some who will not be axccepting, and that is their right to do so.
I almost forgot; I also tow with a super crew at gross combined weights near 12,000 lbs. 22' hard trailer with race car, tools and parts.

 

The engine is pinging to varying degrees. As it gets worse and louder at some point one may consider it knock. Given that my hearing is not great, it is hard to describe precisely when it goes from a heavy ping to a knock. It sounds like from what you are saying is that it would have to be pretty significant to get a sufficient signal on the knock sensor for the PCM to adjust.

As I recall, the local Chevron fuel does not have ethanol. However, I will double check to verify.

I don't recall seeing an EGR system on the engine. I will take a closer look.

I will give the PCM time to re-learn.

The note on Citgo is interesting. Regarding fuel formulation, on the west coast premium has been 92 octane for many years. A while back, I recall premium on the East Coast at 93 octane. Some places use ethanol more than others. I expect that there are formulation differences across the country. I will see if the local Citgo has ethanol. If not, I can give it a try.

 

At the point of actual knock, the sensor should retard the ignition timing until it is no longer detected then retun is back again. The sensor is a 'tuned' design so it does not respond to other forms of mechanical or combustion shocks and it's replacement has to be an exact part number for that engine it is on.
Unless you have something special, you have an EGR system on the engine in one form or another.
Your in a difficult position in Ca. for gas because your wonderful state gov mandates what the gas formulation will be. T From that the refineries have to make the gas to spec. Since this is more or less custom, it falls to fate when the oil supply is interupted so drives your pump prices up out of proportion to the rest of the stsates.

 

At the point of actual knock, the sensor should retard the ignition timing until it is no longer detected then retun it back again. The sensor is a 'tuned' design so it does not normally respond to other forms of mechanical or combustion shocks and it's replacement has to be an exact part number for the engine family it is on.

Unless you have something special, you have an EGR system on the engine in one form or another. Especially in Ca.

Your in a difficult position in Ca. for gas because your wonderful state gov mandates what the gas formulations will be. From that the refineries have to make the gas to spec. Since this is more or less custom, it falls to fate when the oil supply is interrupted or a refinerey goes down, so often drives your pump prices up out of proportion to the rest of the states. Nothing like gov in your life.

 

Only 1999 V10's had the EGR in the F-series. 2000 all the way through 2007, they did not. Which is the reason you couldn't get a 2007 with <10,000lbs. GVWR F-series with the V10 in any "green" states. 2007 CA emissions regs required them up to 10K lbs.

For 2008, it HAS to have one even in Federal trim, I believe.

 

Yep he did say v10. The thread got so long I lost sight of it.

Looking at the Ford service info for v10, they focus mainly on Mass Air , PCV, Baro sensor performance and long term fuel trims in refernce to spark knock problems.
A dealer has to have enough inititive to look at these things to be of any help.
Sorry again for leading on as if it was the smaller engines.

 

The local Chevron fuel pump that I buy from does not indicate any ethanol content.

Disconnecting the knock sensor electrically did not result in an engine codes.

I plugged in the knock sensor, reset the PCM and gave it time to re-learn. It still pings the same.

To summarize…

2001 SD F-250, stock V10, 88K miles, AT, 4X4, 3.73 with stock LT265/75R-16 tires.

The truck pings significantly, even under very moderate engine load, with 87 octane fuel. The pinging is most noticeable in OD at 1500-1800 RPM at very moderate engine loads. It will also ping at higher RPM, but it takes a significantly heavier load or acceleration to get it to ping at higher RPM.

I run the truck mostly 0 to 500 ft elevation. Occasionally I run up to 4000 ft elevation. It pinged heavily pulling a trailer over a 4000 ft mountain pass with 92 octane fuel. That was the only time I had a significant ping on 92 octane fuel.

I have only run Chevron gas in the truck since I bought it 8k miles ago. The Chevron fuel does not have ethanol according to the pump labels.
I replaced the fuel filter, air filter and spark plugs about 8k miles ago - no noticeable difference in pinging.
I ran about 30 gallons of fuel treated with AmsOil PI fuel additive cleaner - no noticeable difference in pinging.
I cleaned the MAF sensor twice recently with spray can MAF cleaner - no noticeable difference in pinging.
I have reset the PCM a number of times by disconnecting battery for 10 hours with the light switch left on - no noticeable difference in pinging.
I added a hose clamp to exhaust heat shield to clamp down securely - no noticeable difference in pinging.
I modified the front cover on transmission bell housing so it was snug up against the housing all around - no noticeable difference in pinging.
I replaced the serpentine belt - no noticeable difference in pinging.
I checked fuel pressure under load at ping condition – fuel pressure was consistent at 40 psi under load and all ping conditions.
I replaced the knock sensor with the identical Ford part number Bosch made part - no noticeable difference in pinging.
The only change that has had any effect on pinging is fuel octane. Higher octane fuel will significantly reduce pinging.

According to the original owner the truck did not ping for years on regular grade fuel. It started pinging in the last year or so when he owned it.

It appears to me that: 1) the replacement knock sensor may be defective, or 2) the knock sensor and PCM are not compensating for heavy ping. There may be other related sensor issues even though there are no sensor fault codes.

At this time it appears that I need to find a competent service tech that will do proper diagnostics to hopefully resolve the pinging.

 

A few things....

When pinging occurs, do you immediately let off the throttle or do you stay at the same point?

At the onset of pinging, the PCM is supposed to retard the timing so that it will go away and not be heard. In fact, technically, you should never even hear the pinging to begin with. This leads me to believe that either your knock sensor is defective, the wiring to the PCM is defective (from the knock sensor), or the PCM is defective itself. While the truck was manufactured to run on 87 octane, given the truck of its size and magnitude, I would venture to say that it SHOULD ping unless there are substantial means to prevent it (sophisticated engine management = PCM). Because your truck pings on 87 and pings less with 93, again, I believe it's knock sensor/wiring/PCM related. I believe you should look into replacing the knock sensor again, testing the wiring from the knock sensor to the PCM, and last a PCM reflash or exchange. At this point, like you said, you may be better off having a tech diagnose it.


Another thought... stupid question... have you checked to be sure you truck doesn't have any sort of chip in it from the previous owner? It honestly sounds spark/fuel table related. Almost like the engine has too much base timing.

Doug

 

That's a very good point. It's very possible it was "tuned" ... check for a chip sticking out the side of the PCM, and it might even be necessary to go to a Ford dealer to see if it's been altered. Or if possible, reflash with a "known good" firmware.

 

I live in Cali, at 4000 ft no less. Mine has had a ping since I bought it.
All my cars ping to some degree, ( I have a flex-fuel Ranger that pings?) the fuel is just substandard out here.
When towing my 11000lb toy hauler, my rule of thumb is never let the engine labor. Keep the motor at or above 2700rpm. Its kind of difficult off the signal lights but I just drive through it.
The pcm seems to take a bit of time to adjust to driving conditions, after a time the pinging will lessen until it is unhooked, driven as a daily, then rehooked to the trailer. Then the process starts all over.
I also hooked it to the trailer after disconnecting the battery. It seemed to set the peramiters of the pcm so as to lessen the ping all around.
I tried in vain to chase mine down only to just live with it.
I bought mine with 96k, put close to 50k on it with only front end issues.
I plan on keeping it through this decade at least.

 

I talked to the previous owner and he confirmed that the PCM has not had any aftermarket reflashes.

The engine pings under moderate loads in OD. Under that condition, when I let off the throttle in OD and press it down, it typically downshifts. After downshifting, it stops pinging. However, when it shifts back into OD the pinging resumes.

Higher RPM does not solve the ping problem either. Climbing a 6% grade at about 60 mph empty/no trailer will produce a significant ping in 3rd gear at 2700 rpm with 89 octane fuel. Changing throttle position incrementally does not get rid of the ping.

 

Have you looked into faulty fuel injectors? If an injector(s) is not performing per spec, then you can get a ping.

Also...I will stick to my #4 post. IMO...you might be in need for an OEM PCM re-flash from you local dealer.

biz

 

Eric ,
not being around ,I just got caught up with your update summary .
Interesting that you got no knock sensor failure code,when unplugged.
How many drive cycles or how long did you leave it disconnected for?

Does your MIL light light up when you turn the key on before starting?

Its too bad you don't have a scan tool.
To really take this any further ,your just going to throw parts at it.

To totally understand OBDI /OBDII and how its components work and how they are all related to keep things running smoothly.The tech or person has to know the functions of all things involved.

To get to the bottom of this its either a proper scan tool or a good tech ,the latter maybe hard to find.

I will rattle this around and see if I come up with some things.

I'm beging to lean towards a reflash as I said at post #18 pcm firmware has a hand in this also.

But the no code light when knock sensor disconnected is interesting.

Rich