I recently purchased a sct tuner w custom tunes from mike at 5 star. My 87 tow tune is giving me problems w spark knock quite frequently. Really annoying so I raised the issue w mike and he emailed me a new tune and made some changes. I appreciated the help but still getting spark knock. Any suggestions what else could be a issue here. I hate to keep bothering him w this as maybe it could be something w my truck 06 f350 w 5.4 no mods except a flowmaster exhaust. I really like the response from the tune but can't listen to the rattle. Went back to stock tune but hate to leave a 400 dollar item in the toolbox and not use it. Thinking bout selling it if I can't lose this annoying sounds from the tunes.

 

Nobody. Alright. Anyone wanna buy a sct 3015 tuner.

 

Did you try the spark advance?

 

I did not try spark advance. Can this be found in the user adjust settings on the tuner. I did not play with any of the adjustable options. to be quite honest i dont know exactly what they all do so i did not want to mess with anything. If this could help would you please explain a little more in depth for the weekend do it yourselfer mechanic to understand.

 

Stupid question and I know not what you want to do... But have you tried running super or 90+ fuel in the truck? Does it go away?

Do you live in one of the areas in the country where regular is 85?

Had a fuel distributor friend of mine test the 87 he gets from the port. It always tests lower than 85, but the 89 and 92 always test slightly higher...

 

I have not tried running a higher octane fuel specifically because my user manual for the tuner states to only use the fuel octane for specific tune. It's a 87 octane tune so consistently use 87 octane from the local Mobil station in town. I never vary from this station unless I am away from the area. I'd try a higher octane if I was sure it wouldn't cause any damage but like manual said it may result in damage. Will it really I don't know. May just be a way of c y a not too sure

 

Call and ask if you can use a higher octane fuel. I've had picky gas vehicles and every time I got a new one had to play around with brands and grades to find the grade it likes the best. I had a Dodge Pickup that only liked the cheapest 87 I could find (usually this was Citgo back then). Super made it ping/misfire. To a Volvo that only like Chevron Super - even though 89 was supposed to be OK. Even Shell Super was quite right in it.

I also wouldn't see how one tank of mid-grade is gonna cause the truck motor to explode, but that is just me. It has to be able to handle variances in fuel quality. But, getting permission from SCT is not a bad idea. Usually the problem is if you use 87 in a 92 tune.

 

To the OP what does spark ock sound like? I've ran a SuperChips Flashpaq on mine and I find when going uphill (engine under more load) the thing kind of pings in 87 octane tune. Rattles a little too.. Is that what you mean, Almost like a can of spray paint rattle..?

I love the tune, but honestly think I'm going to ruin something so alway go back to stock.