Large popping sound

[ThaKing]

My last run at the drag strip was a 13.2. Right before I got to the end I got a hesitation, and a CEL. It was a misfire in cylinder 2. I stopped listened to the car at idle and it sounds normal, idles normal, runs normal, at full rev to red line is normal, drives normal, sounds normal all the way up to wot. At wot as soon as I get into wot a loud popping sound occurs. I am getting Kr when this popping happens but am unsure if it is related possible detonation or maybe something grinding that is in a tight spot (like a dropped nut or bolt or something).

I am going to take the plugs out and check them, do a compression test, and measure the piston heights.

I was curious if anyone else may know anything else to check other than just looking around in tight places to see if something would be in a friction point that would cause this sound.

I am attaching the only log I stayed into long enough (because I am worried even though it pulls like normal wot)

I am also attaching a video that the sound is kind of faint...but you can hear it right before I let out.

[MazdaspeedKills]

Did you check the plug in cylinder two?

[anavrinIV]

you most likely need colder plugs with those mods and you don't have them listed. Pull the plugs and check. Is the pop an afterfire sound? If so a misfire explains a lot there

[865ms3]

@atvfreek; @phate; @rfinkle2;

cj, if you want to come down this week one day we can check everything out.

[atvfreek]

You can see the misfire right when you get into boost. Definitely don't drive the car hard until you can check it out. Check plugs, do a compression and piston height check, that will give you a direction to go in.

[Sid3wayS]

In b4 blown injector seals.
Does it sound like pop corn cookin?

[ThaKing]

I have njk 1 step colder plugs...they were above gap I wanted..and looked bad..so I replaced them today and did a piston height check...1/4 are almost identical...and 2/3 are almost identical...when I say almost I mean you couldn't tell the difference on the dowl rod i was using from the marks...I guess ill see about doing a compression test....Has no one listened to the video? Is there a video with blown injector seals as a sound so I can compare?

[ThaKing]

After reading a thousand or so pages of threads it completly seams like it is injector seals....Although when looking through the IM I can't see anything that would look like a leek...but I will see about doing it and a compression test.

I think I have decided the toyota injector seals fix will be tried.... Hopefully they can do next day...

[Sid3wayS]

You wouldnt really be able to tell from the top like that unless it was VERY bad. Every pic ive seen shows the blowout shooting down

[865ms3]

Originally Posted by Sid3wayS In b4 blown injector seals. Does it sound like pop corn cookin?

ding ding ding. we have a winner!

@ThaKing; @BigBoostMS3; and myself pulled the car down today. Compression test was good. pulled the injectors.......only injector 2 wasnt blown. 1,3, and 4 all blown seals with number 3 being the worst. threw some toyota seals in and car runs good now. ill let @ThaKing; post up the pictures he has.

[Sid3wayS]

Glad I could help.

[ThaKing]

Sorry for just getting to this as it was sunday when it was done, but as he said it did end up being the injectors. I am not glad to be back to power and gas mileage again!!!

Went ahead and ported the one runner, and painted the intake manifold while it was off.

Thank you again Brent and Scott!!

Sorry for the shitty pictures....I took them with a toaster.

[Koke382]

At first I thought your thread said "large pooping sound" lol

Id be scared if my car made a pooping sound.

sent from my peepee