My 05 F250 with a 5.4 with 22,000 miles on it has a pretty decent gas ping, pings with 87 octane and its a little less noticeable with 89 octane but is still there. I am not sure I want to start running 93 octane due to the cost. The truck has been reflashed 2 times but its still there. It pings under load as well as cruising down the highway. Its only has good brand gas, has clean fuel filter.

Anyone know any cure for this? How harmful is it for the engine? Is this common for the 5.4? What octane do you guys usually run?

 

Try a different brand, where you know the gas was refined at a different refinery...

Also, find out about the history of this truck... It may have clues that will lead to a solution.

 

adjust your crank sensor. or you can replace the ring that the sensor reads with a aftermarket one. it is called a timing adjuster that they make for mod motors

http://www.jegs.com/webapp/wcs/store...0001&Ntk=brand

here is a link to it on jegs

 

Before you do that, try running a can of Seafoam through the truck.

http://www.amazon.com/Sea-Foam-Marin.../dp/B0002JN2EU

 

I was thinking seafoam too, however try a different gas stations and a can of gas drier or denatured alcohol too.

Pre detonation is caused by two problems, either too much residual heat in the cylinders or too much compression. Carbon build up can cause both, but if your spark plugs are the wrong heat range they can cause the problem too, it's not just about the fuel. However, the higher the octane rating, the warmer the cylinders can be or the more timing you can run without pre-detonation.

 

dump some Marvel Mystery oil in there too...

4 ounces per 10 gallons...

 

Wow, I wouldn't think you would need to add additives to a new motor. Its completely stock with stock plugs etc.. I have owned it since brand new and have only used mobil, shell, or sunoco fuels. I have only used motorcraft oil and filters since new. I will look into the crank sensor - thanks

 

Yeah this is either timing issues, plug heat range or engine deposits.

So you need to look at what plugs you have and maybe have someone check the timing and timing advance on a scope. But first since it is easier and cheaper you might try an additive.

Additives can be used to help clean out carbon deposits in an engine. Yours is a little new for this but it can happen if you do a lot of short trips or drive like a granny. I had a 79 TA that needed the carbon blown out regularly during the 55 stay alive days. It would slowly carbon up in my sedate daily commute and then it would start running a bit off after a few months. A good romp at well over the speed limit and a bunch of full throttle starts cleaned that car right out.

An additive probably will do the same but you have to use one that actually works. Car magazine articles years ago said pretty much the only one that did work was Techron. The usual STP and Bardhal 99 cent stuff really didn't do much. I would assume this is still true and you will probably need to ante up for the expensive stuff like Techron and maybe the Valvoline cleaners. Don't use that Protech or whatever Chevron calls it. It is just diluted Techron

Or a steady diet of quality detergent gas will help over a long time. Tier 1 gas is the stuff approved by some group for this. I think Chevron, Shell and 3 or 4 others are in this class. And the other guy saying to use some other gas station where you know they get the fuel from a different refinery is right. Most gas stations, including brand names, get their gas from the same refineries so ther emay not be any difference in your local neighborhood. But if they are rated Tier 1 they are supposed to have the required additives and effectiveness, so I have read.

Good Luck,

Jim Henderson

 

Being a new or old motor isn't the problem. I doubt you have the wrong heat range on your spark plugs, at 22,000 miles you still have the factory plugs.

It's the gasoline offered today that is the culprit.

Any more, filling up at a name brand station (like Sunoco, Mobil, Shell, BP, Chevron) doesn't mean you are always going to get good fuel. They purchase fuel from the same refinery as the cut-rate stations. The fuel is supposed to meet the gas company standards, but the fuel quality is not tested unless there is a problem.

Carbon buildup will cause pinging, but so will dirty injectors. Carbon causes a general raising of compression ratios and causes hot spots in your combustion chamber. Both will cause preignition. Dirty injectors can cause a lean condition, which creates a little more heat in the combustion chamber, which causes hot spots and preignition.

Seafoam will clean the injectors and reduce the carbon buildup. Marvel Mystery Oil may also, no experience there. Techron from Chevron also works well. I try to use a good fuel injector cleaner every 10000-15000 miles, just dump a can or two into the tank on your next fill.

One other thing it could be is some sort of vacuum leak causing a lean condition, but you would probably get a CEL in this case.