I had to take the truck on a trip and got pretty low on fuel. Finally found an exxon in a little backwoods town, kind of a mom and pop looking station. I was on empty, the sign said "no ethanol", so I hoped for the best. Anyway, the truck started spark knocking as soon as I left. Pretty sure I've got some bad gas in there, but I've got half a tank or more left. Any sure fire gas treatments I can put in, or do I have to just let it ping until I fill up again? Already had this happen once this winter and after I ran the tank nearly dry and refueled, all was good. Seem to be getting a lot of crappy gas this winter.

I just don't want to risk damage driving with the ping if I don't have to, and I don't really want to siphon 3 dollar plus gas out and waste it.

 

just siphon the gas out and save it for some lawn mowers or something besides your truck. Then just put some gas you know is good into the truck and you should be good. I wouldnt risk running the bad gas in the truck. Had a buddy do it in is 04 hemi he filled it up with bad gas. Siphoned 130 bucks of gas out of the truck and used it for his mowers.

 

i've had the same problem as you. i was about out off of gas and there was a little gas station on this old back road in eastern wa... and is said no ethanol... (this was last winter) and i filler it up took 33 gallons(my tank is 34.5

well it start spark knocking and pinging and ran her down about half way.. then stopped again at a a chevron once i got to ellensburg... and put a can of sea foam in it and it run just fine...


so either you could spend a while sucking the fuel out or just top it off with good gas and do a fuel treatment..

 

+1 on that. Get the best gas you can.

Also hope for no water; You could drop the tank and clean it out check the filter/reg at the same time.

 

If it is truly ethanol free, it might be that the added knock resistance of ethanol is an indication of high compression. I don't know what contaminant could cause spark knock.

 

Errr, I assumed spark knock and misfire are similar/related. Any water, etc could cause poor burn, misfires, etc. Basically, its making the same noise it did when I had 100k miles on the original plugs, wires, and dist cap, noises stopped when I replaced them a couple of yrs ago. I doubt ethanol does anything good for my motor. Could be wrong, though.

At any rate, will try the seafoam (in the tank). Can't hurt anything. Not gonna seafoam through the vac lines, too many threads on people screwing up their trucks doing that lately. Lol

 

I'd try some Techron+ instead of seafoam.

 

Tried some Lucas shizzle I found on sale. It helped, only does it at about 3k RPM now. What's odd is, if you keep your foot in it past 3k rpm, it will stop. Doesn't do it below or above about 3k. Don't really understand that. Anyway, its running well enough now that I can wait until the tank is nearly empty and refuel, hopefully fresh gas will eliminate it completely. I'm generally not in the 3k rpm range anyway. I do know I've been getting more crappy gas this winter for whatever reason. May be plugs are old too, about 30k on them, so probably wouldn't hurt to change them soon.

 

+1 the Chevron with Techron in the black bottle is about the best fuel system cleaner you can get IMO. I'd go ahead and fill it up and dump 2 bottles of that in. Should eliminate it completely and will dilute the crappy gas enough with good gas to where it will run like it should. It was buy 1 get 1 free at Advance last time I was there- don't know if it still is or not though.