Loud popping in the intake
 

So another FRS owner we met this weekend had a scary issue this weekend. He is not on the forum and was going to bring his car in for service this week but I though I would ask you guys first.

Under acceleration he was getting a few very loud pops under his hood. It sounded like a backfire in the intake. He is stock and the issues did not happen until he went into Toyota for what he thought he needed at 5k. Turns out they told him to come back at 7k.

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He is all stock by the way.

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mine does the same thing when it's cold. only once or twice though. sounds like a backfire into the intake.
i can't reproduce it, so i have not taken it in.

Scary part is, he can do it just by revving the engine even after warm up.

I'd take it back to the dealer. He's stock and under warranty.

I get a little popping action but it's definitely in my exhaust. Motiv 2.5" test-pipe into T1R 70R 70mm cat-back

I also get a loud popping noise... atleast once a week. and it happens when I apply a lil too much gas off the pedal

Backfire in the intake? Perhaps intake valves are stuck or improperly timed? Sounds weird though.

I would definitely just take to dealer though. They should sort it out if its and audible pop.

That definitely sounds like something is wrong there. You shouldn't be getting any popping noise from an intake. Only thing you should hear is the swoosh of the induction system. Can't say with such little info, but it doesn't sound like a good thing IMO.

I say install the stock system back and take her into the dealership.

Get it too now for the first time,....approaching 3k miles,....only on cold start up tho,...the weather here has changed (gotten colder) and I contributed it to that,...it is coming from intake as well.....only happens once in awhile,...not worrying about it unless it gets worse.

To day when I was driving, I was in 3rd gear and let off the gas since there was a red light approaching. When the light turned green just a couple seconds later I gave it gas, and a pop sound came from the exhaust. I've heard this sound before, but I can't never replicate it.

Out of curiosity what intakes are you guys with the popping noise running?

All stock for me.And its most definately under the hood.

The guy I posted this about was all stock also.

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Coldest its been since owning the car this morning. About 10*F. Car started fine, immediately into cold idle and after a few seconds of running it backfired through the intake several times, or at least thats what it sounded like. Never touching the throttle. Ran fine after that and on the trip to work.

I've experienced this also. High load, low rpm pop. It can sometimes be replicated by coasting then stabbing the throttle when in 2nd or 3rd at 2,000rpm and below.

I've had the same problem happen to me only once at ~3,000 miles, during cold start. I'm now close to 5,000. Completely stock too.

I went to the dealership for an oil change and a routine inspection. While I was there they pointed out that I had this firecracker noise coming from my intake when the throttle was lifted off of idle. I had never heard this sound before but I had cleared a P0315 CEL a couple times.
To me it seemed that the CEL and the misfires were related so I upgraded all four coils and haven't had a problem since.

Only time any of my 20 odd cars backfired through the intake was caused by improper timing.... seems quite odd on a new car.

Injector malfunction? These Direct Injectors having seal issues?

I don't think it's a seal issue. Seems it's a no close issue. Probably not the direct injectors though, most likely (from experiance) it's the port injectors not fully closing.

yup, most of the intake backfires i have seen were a result of a leaking port injector. My M3 used to do it on warm starts.... if it sat turned off long enough the fuel system would loose pressure and the leak would stop and the gas that was sitting behind the closed valve would evaporate so it would only do it on warm starts.

Exhaust popping is due to over run fuel lighting off in the exhaust and is nothing to be concerned about. If you want to hear it more, get a high flow 2ndary cat and an axle back or catback exhaust.

The Teflon Seals on the Direct Injectors are leaking. Take it to the Dealership and have the tech call Technical Assistance / FTS. Toyota IS aware of the issue.

Which parts should I replace?

Take it to your dealer.

A friend's engine was recently inspected and the dealer found an injector o ring leaking fuel. He said heat could have caused it to melt or it may have been defective.

Mine also has the same issue. O-ring of 1st cylinder is completly gone. The picture is 1st and 3rd direct injectors. I just replaced all o-rings and insulators. I did not have chance to drive yet, but popping when cold start has gone.

Guys,
Are your popping sounds similar to mine?

[ame="http://www.youtube.com/watch?v=Ky_vDK4ePHI"]FR-S cold start - YouTube[/ame]

[ame="http://youtu.be/5iorzUi6Ris"]http://youtu.be/5iorzUi6Ris[/ame]

This is where popping sound came from
[ame="http://youtu.be/jkFmDh_2gks"]http://youtu.be/jkFmDh_2gks[/ame]

A pop, sounds like a back fire. Might be the cat. It can also be engine internals (more like clunking noise upon start-up)

Get it to the dealer. No need in asking us here. It's a mechanical issue at this point.

Does this usually happen within a minute of turning the car on?


Yes! This! I get the popping noise exactly two times though and the car needs to have sat for at least 6 hours.

I thought it was related to my tune but maybe you guys can tell me otherwise? Going back to stock tomorrow for inspection. Time to investigate and stop ignoring it after several months.

Edit: just bothered to read the whole thread. I'm gonna have my tech pull that injector.

That video, what o ring is leaking? An injector?

Teflon seal on the direct injector for cyl #1. Apparently toyota/scion has acknowledged this. Maybe Subaru can figure it out too

Sounds safe! :eyebulge:

I've only had a pop or two on cold-start in the winter a few times, but it sounded like exhaust afterfire.

A little bit of fuel leaking, what's the worst that could happen;)

Strange that you rarely had it when I experience it every morning and until recent temps, the afternoon after work too. The warm weather seems to be preventing it but who knows.

It's pretty vivid that the sound comes from the intake area so your sound may just be irrelevant to this

I'll have to have a buddy start the car while I look under the hood. I had enough leaky fuel bullshit with my Impreza, thanks. :thumbdown:

Not sure. On the EJ motors it was the front one on the passenger side. I wonder if that means its the rear of the drivers side bank for our cars :popcorn:

Hey man, keep us posted. I, too, would love to have this shit fixed already.

My symptoms are exactly like yours. During the winter, my car used to pop after work or first thing in the morning. Even if there was no popping sound, I could still feel the "micro-explosions" through the chassis.

Does Toyota have any written info on this issue?
Subaru is playing dumb...