My pinging came back a couple of weeks ago. So I did what I did last time to get rid of it. I disconected the battery and cleaned the MAF. It didn't work this time. I have a V-10 Excursion.

Get this. Since I am in the D/FW area, winter in Nov/Dec is a little on and off. One day it is pinging like crazy, the next day....not one bit. The difference?

When it wasn't pinging, it was about 70 degrees. Same tank of gas, same everything.

Then it got cold again. Pinging came back. Then it got warm again. Pinging gone. Same 87 octane gas. I'm literally talking one day to the next. You guys from TX know what I mean.

I bought this truck a year ago. And mostly during last winter, we were towing out travel trailer. We put in 89 octane when we tow because we get better mileage. So, there was probably a lot of mixing 89 and 87 octane, so maybe that's why I didn't notice it then. All spring and summer, no pinging. We haven't towed since Oct. So, we've been on 87 octane for a couple of months.

Is there a sensor for the temp of the incoming air that might be malfunctioning?

An O2 sensor?

Seems like some sensor is not giving the correct info to the computer.

Any ideas???????????

 

Yes, there is an intake temp sensor - depending on the year, it's either in the intake tube, or incorporated into the MAF itself.

What year truck?

However, it defies logic that it would ping when it's colder outside. Even if the temp sensor were bad, it would ping when it got WARMER not colder.

Are you sure it's a ping and not an exhaust manifold leak?

 

About 3 years ago my 2002 F-150 SC with the 4.6 started doing the exact same thing. It would run fine on 87 octane if the outside temps were 60 ish and above. Below that it would ping like crazy. I cleaned the maf and it didn't change anything. I even put in a new intake air temp sensor. It didn't fix it. The timing is being advanced when it drops below 60 outside. I know because the truck runs better, more "pick up and go" than when it's above 60. So I was running 93 octane for 6 months of the year, Och! I was expecting it to ping on 87 again with the onset of Fall but it didn't and isn't. Though the timing is advanced again because it runs better but it's not pinging on 87.

The only thing different is in June I began to "religiously" add to my tank, everytime I got fuel, a fuel additive. Actually it's brewed in Texas. You can pm me and I'll be happy to give you the info since they are not a site sponsor as far as I know. How and why it works I have no idea other than maybe it maintains a real good spray pattern and amount of fuel being injected due to it's gentle and constant cleaning and lubricating.

I wonder if the $45 replacement iat sensor I bought is bad also. I did tests on the original one and it failed the voltage test prescribed. The replacement also failed the voltage test. Both of them are receiving the correct voltage though.

Whimsey

 

Colder ACT sensor input to the PCM can yield a bit of spark advance. The PCM retards the spark advance as the ACT input climbs in temp. This is to prevent ping/detonation. When it's cold,you don't see this spark retard and depending on how cold,it might be advancing the timing.
JL

 

Johnny, I have an '01 Excursion...

 

Doesn't matter. They're ALL programmed the same with minor changes based on platform. But,the basic strategy and function is the same.
JL

 

Shouldn't the knock sensor detect the problem and pull the timing back?

 

Having messed around with cars for 25 years, I am certain that this is detonation not an exhaust leak but I do appreciate the question since colder (not hotter) causes the problem. I just filled up with midgrade 89 octane, so, we'll see what changes. Of course, it will be 75 degrees here in a few days....

gotta love it!!!!!

 

Until it hits the knock sensor max spark retard limit. Then it's pingsville..
I've said it a few times,and I'll say it again. The OEM tune on these Trucks/Excursions is terrible at best.
JL

 

Another thing to watch for is, in different location of the country the gas is changed at various times of year, summer blend and winter blind, and this can make a difference.
Also gas can change from station to station.
I also have a slight pinging problem at times with my V-10, but haven't nailed it down yet either.

 

I've wondered about that too. Also, what effect is the 10% ethanol having?

 

Yeah, Johnny, we've talked about it before, but DANG! $500 for a tuner! That's steep bro...

 

About $400 for a tuner. A set of tires can easily cost over $900 a set and they are consumable. Fuel, insurance, repair bills and etc. The price of a tuner pales in comparision to the cost of other things.

On a side note the SCT Eliminator Switch Chip is cheaper than a handheld tuner.

 

I agree with DKF. They're around $400,and besides having a tuner,you also get an invaluable scanning/datalogging tool for diagnostics.
JL

 

And improved performance.

And depending on how much you drive maybe enough mileage increase (don't count on a lot) to pay for itself over a few years.

And you can prevent the pinging from pinging away the tops of your pistons.