Pinging under medium load

[M5OD]

2000 3.0, pings under moderate loads at any RPM (downshifting to 3,000 RPM makes little difference). 77,000 miles and pretty much all original as far as I can tell. I've been running mid-grade gas (89 octane) and it's better, but still totally unacceptable.

If I wanted to actually haul a moderate trailer I think it'd ping at any slight incline. I cleaned MAF, should I replace upstream O2 sensors? I've heard that the OEM coil-pack had something to do with it, but that makes no sense to me as weak fire would not cause pinging or change timing. There are no vacuum leaks or trouble codes.

I just don't want to throw parts at it, and I don't have access to a live data scan tool anymore.

Overdrive!

 

[RonD]

There is no way to change the spark time, so spark plug fires before self ignition can occur.
Knock sensors did this but are no longer used

Could be EGR valve and pipe is getting clogged up.
The Exhaust gas, when mix with the fuel/air helps cool the cylinder temps, this reduces NOx emission and also reduces pinging.

Also check the two hoses/lines on the DPFE sensor, look for cracks or leaks, the DPFE sensor tells the computer how much exhaust gas is being fed into the intake.


Pull out a couple of spark plugs and see what they tell you, black coating is carbon building up and that retains heat which causes pinging.
Could be you are running rich, which cools cylinder, until carbon builds up.

Leaner fuel/air doesn't cool cylinders enough, and also has a lower self ignition point so can cause pinging.
Run a can of SeaFoam in the fuel tank to clean out injectors and some carbon.

Once pinging starts it is self sustaining, pinging is a violent "dual" explosion in the cylinder, so creates even more heat, it can eat away at pistons until they fail

O2 sensor data does fine tuning for the fuel/air mix, so a failing O2 sensor could cause a rich or lean mix, but this would usually set a code(CEL would come on)
MAF sensor is the main sensor to set fuel/air mix.

Small vacuum leak can often cause a lean mix at first, PCV valve hoses are a pretty common leak point on the rangers, check the elbows closely

 

[bg@f.ord]

I had to replace my synchronizer/ sensor & noticed my E.G.R. elbow was collapsed & replaced it also.My truck was pinging.I think the worn out syncro through my timing off enough to cause the pinging.It doesn't ping anymore.

 

[stmitch]

The 3.0 loves to develop carbon buildup in the combustion chambers. I'd run a decarbonizer (like Seafoam) through it to start. Then I'd look at EGR components and the DPFE to see if they need to be cleaned or replaced. If your truck is flex fuel, I'd try and run some e85 through the tank too.

 

[McCormack]

Running a 180* thermostat will reduce pinging significantly. I eventually ended up buying a tuner for my '00 3.0 and bumped my timing back a couple of degrees and that eliminated the problem completely.

 

[RonD]

Running a 180* thermostat will reduce pinging significantly. I eventually ended up buying a tuner for my '00 3.0 and bumped my timing back a couple of degrees and that eliminated the problem completely.

As temporary measure you can do this but running the engine below 190degF minimum uses more fuel(which is why there is less pinging) and can cause you to fail emissions tests, if you have to pass those.
Also, oil stays cleaner if engine coolant temp stays above 190degF for at least 15 minutes.
That is why short trips can gum up the oil and suck up the fuel, engine never warming up means oil temp can't get hot enough to burn off the water(condensation) in the oil or the fuel residue(blow-by).
Running 160 or 180 t-stat means oil runs cooler as well, on longer drives it wouldn't matter, A.S.A.(the oil testing guys) say water or fuel will start to "burn off" starting when coolant is at 160degF, but it takes longer than at 190degF, which is why most manufacturers now run engines at 195 minimum, also helps lower emissions.

 

[M5OD]

Thanks guys. Truck is a FlexFuel, however I do not have access to E85, none in the state as far as I know. This truck only had 70,000 miles on it when I bought it last year, it was 13YO. I suspect there may very well be carbon build up, will run some Sea Foam through it.

So if I'm reading this correctly the Cam Syncronizer can't be mover to retard timing at all.... Also there is no knock sensor on these engines (I'm a European car guy and am used to the early 80s Bosch Fuel Injection/Ignition).

We don't have emissions tests here in Maine, if some Sea Foam and a good tune up (with MAF cleaning and/or replacement) doesn't solve this I'm going with 180F thermostat.

Overdrive!

 

[Earl43P]

DPFE replacement fixed my pinging.
Several times.