Hi been boosting my car for about two and the half years now (5000 miles total) and only on the weekends. Yesterday while boosting I heard loud bang . Sound came from the engine bay. I was in third gear at about 3000rpms then pulled all the way to the red line at about 9-9.5 psi. When I took my foot off the gas at the read line to hear my BOV, instead I heard loud BANG. Pulled over, inspected the car and didn’t find anything wrong. After inspecting my car I drove it for another three hours and boosted it at least 10 times but only up to 5500-5800 rpms, everything felt normal. Car was holding 9.5 psi in 2nd, 3rd, 4th and 5th gear. Idle, afr and drivability of the car was same as it was in past two and the half years. Today I’m sitting and thinking what that loud bang was . One more thing I also changed my oil recently and I went from GC 0w30 to M1 0w40. Could it be oil?

 

backfire maybe, but you said you heard it from the engine bay so idk

 

define bang.

Pop, metal on metal, boost sound associated with it, etc

 

Brooklyn! Gunshots?

 

drago???

haha its alex, kuzmicki's cuz... call me up, might know what it is

 

maybe it was just your head hearing it in the front of your car.

i spit flames and a big bang every time i power shift.

then again i'm running no cats and probably the most free flowing exhaust you can buy. (jic)

 

it was a metallic sound

I keep and drive my Z in PA

I MUST BREAK YOU. Yes it's me . PM me the #

 

Check under the car. It might not be neccessarily an engine problem.

 

^^^ Good point.

 

I prob scare to drive few hours plus in boost if i hear " BANG " from my engine bay. LOL

I would do compression test, if you ran 2 1/2 years. Even it was just a weekend drive. Also I probably get ready to build motor on the side.

 

Not sure if you have a cat/cats or not, if it heats up enough it could ignite the fumes from running rich, fuel droplets from the injector may not have ignited and at that velocity and shot out through the exhaust.

 

My accord used to backfire out the intake on redline shifts. (as in my case) It could be detonation causing a backfire out the intake as was my case...whatever the cause if this is the case, is def. not a good thing. Check your compression and a/f

 

i first thought your motor mounts...but you said it hasnt happened again since?

 

Maybe you rain into a pigeon.

 

what ems are you running?

 

Why would you run it to redline after hearing a bang? LMFAO

 

^ya now, the only way to see if something is broke its to keep doin it!

HAHAHA

 

He said he started at 3000RPM, went to redline, let off and heard the bang. Not at 3000RPM, I vote backfire.

 

I would drain you oil and check it for debris. possibly something on the inside blew.

 

I meant after the incident he still redlined it-to check if it happened again I guess.

We need a better description of the noise!