Idle tip-in/throttle blip knock

[Nfsundrgrnd]

Originally Posted by Clipdat

Great description. I also picked up a bottle of Chevron Techron concentrate fuel system cleaner the other day when I bought the MAF cleaner spray. Planning on using it at next fuel up.

But yeah the car/engine seems to be running fine aside from this. Pulls hard and seems to be making the normal amount of power. Plenty of regular tractor-like noises and clicking/ticking coming from the engine as well, which by FA20 standards is a-ok normal. I can really hear all these lovely engine noises now after putting on this quiet axleback. Previously the crazy boom and resonance of the old muffler just completely drowned out the engine noises almost completely.

Yeah that might be a good idea to run a fuel system cleaner. Let me know if it ends up improving with it! I'm also gonna put my straight piped mid-pipe back exhaust back on to drown out the noises haha. It's not too concerning since I can just feather the throttle for now, but there's definitely something going on. Hopefully we can get to the bottom of this on this thread once and for all haha.

[NoHaveMSG]

Originally Posted by Clipdat

The car is currently on the stock tune.

No other mods, just catback right?

IAM is a bit low so it being stock tune does raise a bit of a red flag. LTFT is also high positive, but don't know engine temp and injection mode. I'd ask you to do a log then but I am drawing a blank on some parameters that we would need to see.

[Clipdat]

Originally Posted by NoHaveMSG

No other mods, just catback right?

AEM dryflow drop in filter, Perrin silicone inlet tube, and Fujitsubo Authorise S axleback. That's it as far as power/engine performance mods.

[NoHaveMSG]

Originally Posted by Clipdat

AEM dryflow drop in filter, Perrin silicone inlet tube, and Fujitsubo Authorise S axleback. That's it as far as power/engine performance mods.

Have you considered flashing an OTS tune to it to see if it fixes it? Just curious. The stock maf scaling is sometimes not good. I messed up scaling my maf once, went the wrong direction, and it causes all kinds of drivability issues and dropped IAM with no codes.

[Clipdat]

Yep. I was actually getting ready to flash an OTS tune, but then that stuff with the stalling/MAF sensor happened so I held off until I could ensure that the car was healthy.

[Ultramaroon]

FWIW, I believe that the knock/ping/detonation is real. I still wanted to rule out the other stuff.

[Nfsundrgrnd]

Originally Posted by NoHaveMSG

Have you considered flashing an OTS tune to it to see if it fixes it? Just curious. The stock maf scaling is sometimes not good. I messed up scaling my maf once, went the wrong direction, and it causes all kinds of drivability issues and dropped IAM with no codes.

Flashing the OTS tune did not fix the knock for me unfortunately.

[NoHaveMSG]

Originally Posted by Nfsundrgrnd

Flashing the OTS tune did not fix the knock for me unfortunately.

That is a start. I'd say do a log and see if we can see something odd.

@tomm.brz this may be getting into your realm of expertise. Something you have seen before?

[Nfsundrgrnd]

So I got a video of the knock, you can hear it loud and clear once I put the camera outside. I also logged these blips but gonna need to upload it later.

[Nfsundrgrnd]

It's almost like the ecu can't trigger the direct injection fast enough when activated with the throttle blip.

[tomm.brz]

need a log of precisely that happening while recording the log to say something

also 91 oct ca nt be good enough for the stock tune and advance multiplier should drop accordigly

Also if you take a look at knock correction table of stock tune you see the "worst" knocking area for Subaru is right at low rpm high load so when you jump on throttle suddenly on low rpm



I d bet you have one of the first revision of the 2013-2014 tunes, which don t have a timing revisions from Subaru during fast transients/blips so timings can get too high and cause pre ignition and the most common failure caused by this is the oring in the DI injectors that disintegrates

i don nt think one is able to hear the proper engine "knock" sound just by blipping the acceleator, but you can clearly hear if the oring popped, by a loud popping dry sound when you quickly blip the throttle

Without a video of the sound and a log anyway is difficult to guess


EDIT: oh well the OP is providing while i was writing this, so i ll wait for the logs

[tomm.brz]

from the noise, it sounds indeed like an oring popped, try to make a video with engine bay open and have someone blipping for you while you record

it gets loud when done like this so it s easier to confirm but it s already 95% popped DI oring for me


You ll need to replace the oring within all 4 injectors, then flash to OTS tunes as they have the fix already, or a more recent stock tune , or a custom tune directly

[Nfsundrgrnd]

Originally Posted by NoHaveMSG

That is a start. I'd say do a log and see if we can see something odd.

@tomm.brz this may be getting into your realm of expertise. Something you have seen before?

Got the Log right here!

https://www.dropbox.com/s/k0uqa9cnq9...Knock.csv?dl=0

No knock correction which is interesting...

[Nfsundrgrnd]

Originally Posted by tomm.brz

from the noise, it sounds indeed like an oring popped, try to make a video with engine bay open and have someone blipping for you while you record

it gets loud when done like this so it s easier to confirm but it s already 95% popped DI oring for me


You ll need to replace the oring within all 4 injectors, then flash to OTS tunes as they have the fix already, or a more recent stock tune , or a custom tune directly

This is currently with the stage 1 OFT tune as well.