Alright, so the Evo has been going strong for about 30k miles when I swapped cams then got tuned. Well. I had to get a new battery. And my check engine light is programmed to detect knock, and now it's going crazy! There is an oil leak from the valve cover gasket, which is being replaced whenever the new one get here. Could they in anyway be connected? Nothing has changed except the battery and that leak. I know taking out the battery doesn't delete the tune, but that almost seems like that's what may have happened. Any suggestions?

 

check your plugs, check compression, check AFR in comparison to the change in temps

 

Bad fuel? Change in atmospheric conditions?

Just how much knock are you getting? Are you getting it consistently?

 

I can hold WOT and it only knocks between 5-7krpms. It is very consistent. It's been going on for about a week now, so I've filled up in that time. Plugs were swapped pretty recently.. It does sometime start out flashing slow (around three counts of knock)? Then begins flashin quicker as I hold it to redline

Maybe it could have something to do with the temps dropping here? I never thought it'd drop enough to cause such a spike in knock though.

 

yes, temps can change the behavior of tunes, especially if you are tuned near MBT (aggressive)

you are most likely over boosting

contact your tuner, or start educating yourself on how to lower your boost, if you don't know already.

 

I do know how to lower it, I've been watching the boost and have been noticing it knock pretty bad even when around 15-20psi. It was tuned at 25 if I remember correctly

 

What was used to tune your car? Do you have a wideband on it? Do you have a way to datalog a pull? What are your mods?

 

Evoscan, I do not have a wideband, I personally do not have the software to get some solid info, and it's pretty much a full bolt on car with aftermarket cams and intercooler. Now that I think about it, this is the first time the intercooler has been on the car in cool temps. The intercooler was put on after the tune

 

Well if you have an MBC turn down the boost for starters. Regardless though, you'll probably need your tune adjusted to help alleviate the problem.

 

Winter gas and summer gas blends from the refinery are different. Winter gas is less knock resistant.