Engine Engine Knock Thread

jayochs

New Member
Aug 6, 2014
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So I figured i'd post this over here too as I initially posted it on Mustang Evo, but I want to get some more opinions!

Pretty much, I got an MPT Performance 87 tune as I wanted to keep the car running 87 because well, the 3.7 was made to run regular, and now in NJ with this ridiculous 12% gas tax, i'm in no mood to be paying almost $3 a gallon for 93.

So I got my MPT tune and I noticed the engine would always knock in low rpms when giving it gas. it's a quick little CLONK sound. i have no idea if it's pre-ignition, or spark. I ran data logs and everything, sent to MPT, and I had 4 revisions done, and they all knocked exactly the same. I'm over my month period since getting the tune, so I doubt they'll help anymore, but pretty much if these 4 didn't fix it, they can't fix it because it obviously has to be a problem with my car.

i thought it was the tune, but when i went back to stock, i realized i could still hear it when shifting.. the tune exacerbated it because, i believe, the increased throttle response would allow for more throttle at lower rpm's when i shift, thereby pushing the engine and making it knock more than it did stock..that's my theory anyway.

MPT's response was stop using 87, try higher grades, and if that fixes it, that's your problem. that was a lot of people's responses, too. they also said to try quality gas stations..problem is, the only stations by me are Wawa (which apparently is crap, who knew, i always used it..), Lukoil, and Sunoco.

so i tried 93 from Sunoco. it knocked slightly (3rd gear is always the culprit, when I shift into 3rd in my neighborhood around 20-25mph and give it gas as i come out of the shift, it would knock) and SOMETIMES it did it with 93.

which brings me to this: the 3.7 was made for 87; hell, so is the 5.0. why in gods name does MY 3.7 require 93 in order to like 98% stop knocking? i mean hell, it didn't even 100% fix the issue.

i'm not getting a CEL saying my knock sensor is bad or anything, i don't think there's any issue, but i have no idea. again, idk if it's preignition or spark. I've got a video if anyone wants to listen and see what their opinion is; i've already spoken to both Volt and VIG about this, and Volt's even looked at my datalogs and we haven't come to any conclusion. the sound i hear to me sounds identical to when you don't give the car enough gas from a standstill when you're letting off the clutch and the engine starts to knock.
https://www.youtube.com/watch?v=IAk7iTiGqgs

In this video, at exactly 9 seconds, you can hear the first knock when I shift into third..it's after the sound of the shifter going into gear. then skip to 53 seconds, and right after i go over the speedbump and shift, you can hear a loud knock. it's like a clanky CLONK sound. it's weird.

https://www.youtube.com/watch?v=DylFSDrjxgk

in this video, goto 39 seconds. i'm purposely doing crappy shifts because that's when i can always reproduce it. you'll hear it shift into 3rd, then clonk.


this video is an example of the knocking sound on a manual when you have a bad start..giving gas at low rpms..and this is identical to the sounds posted above:


View: https://www.youtube.com/watch?v=YUumzeRP7f4



i said what the hell and took my airaid modular intake tube off and put the stock one back, still did it. put airaid back, and flashed tune back to stock. went around the block, and it was still knocking. it's 100% not the tune, and it's 100% a problem with my car it seems.

i suppose at this point, if it IS engine related, it should be covered under the 5 year warranty right? i'm at 20k miles, and the car was made in 2013, so it's still covered. might as well flash stock and go to ford and have them check it out now. what's gonna suck is i always do night drops because i work during the week, so i just let them do their stuff and i pick it up after work usually...so if they get back at me with "oh we didn't hear anything" i'm going to be pissed.


is this something that could potentially be alleviated by colder/warmer spark plugs, or something? i'm not a gearheard so unfortunately i'm not well versed in any of this.

thanks guys!
 
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I had some transmission shifting issues in my automatic select shift for my 2014 V6 with the MPT tunes. I stopped using them. I now just use the SCT options on the tuner, and the car shifts really smooth plus with extra speed. They just automatically tune your car to perform better I found out. As to your issue I'm not sure. I know my user manual says DO NOT use any other octane than 87 as other octane can ruin the engine. I have used 91/93 before but the car was tuned for it at the time. I hope you can find out what that is, because that would definitely have me worried! Yeah if you have the extended bumper to bumper warranty with Ford still in effect, I'd definitely take it to them with everything back to stock settings and 87 octane ran through your lines with a couple fills... don't want to give them any reason to void your warranty.
 
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