Well an update... I put a full tank of premium 93 octane gas in. Guess what? No more pinging...

So... what do I do from here?!

Here are my viable options:
-Just run premium... costs me an extra $5 at the pump.
-Run about 5 tanks of premium...
-Bring it to the dealer with premium and say, "here, it fixed it, but I can't run premium in it all the time."

So what would cause this kind of situation?! Would it be something with the timing? Cold weather? Spark advance/retard?!

I'm totally freakin' baffled.

 

Nevermind...

 

I have been runnuing premium in my 04 for most of the year because I couldnt take it any more. Its not just you and I buy my gas from the same BP all the time I have tried differnt places and grades like you are doing and nothing changed. Most gas stations buy gas from the same fuel depots unknown to most people its just hauled in the that companies trucks to the station.

 

you don't say.........

 

What confuses me is why does it only ping when the truck is warmed up? When the truck is warming up, it doesn't even do it.

 

The pinging happens when the combustion temps get so high that the fuel burns before the spark plug can light it. When the engine is cold or just warming up there isn't enough heat to cause pinging so it runs normally.

 

Gas may be the same, but the addatives from each brand vary. That's why I only run Shell. I am not buying gas from a company that pays ford to recommend them just because.

 

This is very true.

 

I am not buying my gas there because Ford says you have to run it in their vehicles. They just happen to cover most of the territory that we travel and the other station that we have the most of is Citgo(not really much of a choice).

 

I dunno... I was thinking about it... as long as my truck runs fine on premium... it can't kill me to run premium... like that extra 5 bucks is gonna kill me. haha

 

i had pinging before the 93 octane tune, even on the stock tune, my pinging got way better running midgrade, but even better running midgrade from shell, and BP. now with the tune, i have to run premium, premium from sunoco, citgo, gives me pinging or "knock sensor" noise, but it all dissapears when i buy BP, or shell, but shell is another town away... the morale is, you may hate BP like i do, but try it, it works better, and shell is a notch above that

 

If it doesn't ping when it is warming up but does when it gets warm, I wonder if you could change the thermostat to a cooler one. Sounds like the richer mixture from being cold is helping it.
Premium gas is doing one of two things IMO: masking the problem detonation from an unknown mechanical cause which could be anything from a bad cam or some other defect in the valve train or even possibly a coolant system blockage
OR, masking a problem in the ECU and electronic engine controls function, such as improper timing map, or injector driver circuit overheating issue, and yes about a half dozen different fuel mixture control inputs.
On the ignition side, I wonder if just one COP coil being weak would make this thing ping, seems like that would be picked up as a rich O2 reading
though.
If your thermostat is easy to get to, It woulldnt hurt to get a 160 degree one and see if yoiu can fool the ECU.

 

Eh... I'm not too sure if I want to do that... because it would still fool the ECU. :\

Not too sure what I want to do... I plan on changing the fuel filter soon... but I highly doubt that is the problem... but you never know what is in gas these days.

What the heck is baffeling me is the following:
1. It only does it AFTER it warms up.
2. It just started like 6 weeks ago out of the blue.

I'm going to pull the plugs this weekend (if I got time), and look at them. If I don't see anything out of the obvious, then I'll move on to the O2 sensors and see if there is something wrong with them. Other than that... the only thing else it could be would be something related to the ECU and ignition timing. There must be a reason why the truck is trying to advance or retard the spark. Then again, the gas might be spontaneous exploding in one or two of the cylinders creating the knock.

Let me ask you guys this. As I couldn't really find a straight answer... Does the gasoline volatility vary with grade? Like is 87 octane more volatile than say 93 octane? That's what my common perception was... because running 93 in an engine set for 87 with a low compression will make it harder for the engine to properly ignite the gas.

If that is true above, then basically my engine is acting like a diesel engine, in one or two cylinders when running on 87 octane... because if 93 fixes the ping, it is because it is less volatile of a fuel, thus inhibiting predetonation in the engine, thus making the engine appear to be functioning correctly.

However... I was already reading and researching that the 89, 91, 92, 93 octane fuels have special detergents. So if I do have a carbon buildup... which I highly doubt after having the dealer run 2 cans of BG44k through the engine, it should totally get rid of it running the premium. But.... I was reading someplace else, by running a premium fuel in a regular grade gas engine will create twice the carbon deposits because it is not burning correctly. This is another place as to where I am kind of confused.

Sigh... I always have car troubles...

 

Bump... Anyone know? Or doesn't anyone want to help?

 

I'd help, but I wouldn't be helping much.