Exhaust Pops every 30 seconds or so....

[Strm Trpr]

Gentlemen:
I've got a question about our cars.
I think I've read it some where, but I've been searching for something along these lines, but I can't come up with anything.
Car starts perfect everytime....
While idling at a light or what have you, it just pops out the exhaust once about every 30 seconds or so.
Is this natural for our cars?

Mods:
NGK Wires
BPR6ES gapped to .030"
Complete front of engine overhaul
New T-Belt w/BSE
All boost leaks so far have been fixed.
Just did my injector seals last night, and fixed the studder I had coming into heavy boost.
It only pops while idling never while driving.
Could it be a small vacuum leak.
I haven't done the TB Shaft seals yet, they're next.
Any thoughts?

 

[98RedGs]

Tried gapping the plugs at about .028 ?


OH!, moved to problem diagnosis.

 

[Strm Trpr]

Cool thanks for moving the thread.... I wasn't sure where it went so I figured General Noobie was a good place to start.
I will gap the plugs to .028" tonight when I get home and see if all is well.

I'll let you know....

 

[cfisher]

i get popping also but mine occurs whenever i downshift when slowing down. especially around 2K. i've been told no cat will cause this.

 

[UndergroundR32]

Same here, but I have a ghetto exhaust. No muffler and it exits just behind my seat.

 

[Strm Trpr]

Well, last night I gapped the plugs to .028".
I found 2 of them gapped at .030 and the others were .028 & .029.
I was like hell ya, that should fix it.
So I changed the oil fired it up and it sounded great, no more pops.
This morning when I get to work I leave it idling just to confirm it's dialed,
well when I walked back there it was popping worse than before.
I'll check it later and see what the Fook.
I'm thinking my Intake Manifold Gasket is leaking.
I just replaced the injector seals and everything.
The only thing that I have left to do is zip tie all vacuum lines, replace TB shaft seals, & both TB gaskets.
I need to do a compression test, and I would assume a leak down test would
show signs of a leaking gasket right?

 

[Coldandafraid]

is it popping like its lean?

 

[Strm Trpr]

Well, while it's idling, it kinda pooofffsss every now and then....
When I regapped the plugs, they all looked the same, nice and tan....
I can't figure it out....
When I get home I'm gonna do a boost leak test to see if I can zero in on the problem.....

 

[pinknuggit]

most every car will do that.
It's just unburnt fuel that ignites in your exhaust tract.

What kind of exhaust do you have ?

in my truck, i run straight pipes dumped under the back bumper with no mufflers or cats. Whenever i'm on the hiway and i'm slowing down, I can throw it into 2nd gear and it sounds like someone is in my bed firing off a machine gun!! Anytime the engine is decelerating, it does that.

My buddy had a ford truck where one of his injectors was stuck open and every few seconds at idle his exhaust would pop. What kind of shape are your injectors in?
If one of your injectors has a drip when it's closed, it can do what you're describing.

 

[Strm Trpr]

Cool man, thanks for the info.
My exhaust is stock with an aftermarket muffler, (bought the car that way).
Injectors, well I just replaced all of the seals and when I pulled the fuel rail up and out, non of the injectors were drippin.
I didn't remove the plug from the fuel pump and let the car die, so I still had pressure in the rail.
My injectors looked fine to me, plus they only have 73.5k on them.
I don't know anything about fuel injectors, and you could be very right.
Funny thing is, when I decelerate, my car doesn't pop at all, it simply revs down with the gear, no popping.....
The performance of the car is fine for a stk system with the T-25, I just don't want to be sitting at some light with a full 3" system with an N1 tip and it
pops likes that, then people would hear it and think my car is running like poop.
I didn't get a chance to work on the car last night, but while I'm waiting for my softball game to start, I'll try gapping the plugs to .029" and see what that does.
At .030 it only popped once about every 30 secs.
At .028 it pops more often.
So hopefully at .029, I'll find the happy place and roll with that.

Thanks again......

 

[pinknuggit]

hehe. who cares if people think your car sounds like it's running like poop. That means they are going to be even more surprised when you beat them.

yeah, not all drip from an injector can be visible. You might want to call around and see if there is any fuel injector clinic/shop in your area. When i took my 450's off of my car, they looked fine and I thought they were good. I took them down to the fuel injection shop and the guy flow tested them for me for free (he flows them for free for people, but he charges you if he has to clean them or balance them) and two of my 450's were below 380cc/min on flow, and another one had a hairline crack in the pintle cap which lead to a small drip whenever the injector would open. ! ! talk about major disapointment. hehe
You might be lucky and find an injectoion shop near you that will flow test yours for free.

I don't think a tenth of an inch will have as much of an affect on your engine as what you're describing.
Before you yank your plugs out again, i'd reccomend either Seafoaming or MCCC'ing your engine. This will clean out any buildup you have.
After that, I would change your oil and run a tiny bottle of Two Sroke oil in a full tank of gas. Then, on your next full tank, dump a bottle of ATF in there. That will clean your injectors and make sure your fuel system is working at its optimum.

I didn't really think about it but you might want to find out if your problem is unburnt fuel or if it's a misfire. Can you feel the engine buck whenever it pops? Can you feel anything?
If you can just hear it, then it is probably just fuel, but if you can in Any way feel it through any part of the car in the form of a vibration, you're probably misfiring.

like i said, i'd try either seafoam or mopar combustion chamber cleaner before you do anything else.

 

[Strm Trpr]

Cool man thanks for all of your info.
1qt of ATF in the gas tank
Damn I don't think that stuff belongs in there, or can it go in your fuel.
I know that sh!t can ignite, but I've never heard about that.
What about Marvel Mystery Oil.
My dad used to run that stuff all the time.
I'll check on Seafoam, i've seen it on the forum, but still can't figure out if you guys are f'ing with people, or you're serious.

Peace

 

[Strm Trpr]

Hey, I found that Sea Foam sh!t online, cool, I knew you weren't f***ing with me.
Man, I just changed my oil too....
Oh well, I'll live with it til my order of Sea Foam comes in.

Thanks Again

 

[pinknuggit]

Hey, I found that Sea Foam sh!t online, cool, I knew you weren't f***ing with me.
Man, I just changed my oil too....
Oh well, I'll live with it til my order of Sea Foam comes in.

Thanks Again

hehe no prob. I love helping people out when they will listen to what i have to say.

Yeah, ATF is an old grease monkey trick to clean out your injectors. It also will help your rings seal against the wall to an extent. Two stroke oil does the same thing and also raises your octane level.

 

[my95tsi]

Mine pops too. Nothing really to worry about i think it sounds mean.

 

[Strm Trpr]

Lately I've been hearing what sounds like an exhaust leak.
I haven't had a chance to jack the car up and listen to wear it's coming from, but it only happens now that it's colder, and only in the morning, when the car is not up to operating temp.
Once I'm up to temp all is well, except for the intermittent popping.
Could the exhaust leak be the source of the popping sound?
I plan on doing a new exhaust system with all new gaskets and studded exhaust manifold as soon as I find out my fate for a speeding ticket this Thursday.
So I'll end up running a SBR Cast Manifold, ported turbine housing w/34mm flapper mod, ported O2 housing, 2.5" Turbo back exhaust with a 2.5" high flow cat. Then I'm going to clean and port match my Intake Manifold and install new gaskets....