Farting sound when hammering it...

[SmellSoGood]

Any ideas what this weird farting sound (as long as throttle is pressed) is when hammering in 3rd, 4th and 5th gears? Am I in the wrong gear or RPM - hard to image since I get this at when mashing it, but not at the red zone in the RPM range. For other explanations of the sound - it sounds like a tractor trailer letting go off the gas and getting that obnoxious exhaust note in a low gear (???).

 

Your insights will be valuable when the dealer tells me, "this is normal under various operating conditions and within thresholds".

 

Thanks,

[blkGT500nCA]

Sounds like detonation. Do you have any mods on the car?

[07SGT4578]

Farting sound when hammering it...

[DDT]

Farting sound when hammering it...

 

 

Too much Broccoli, Cabbage, Rice& Beans?????

 

"Smell So Good"?????

[GT500692]

" obnoxious exhaust note " Thats the jake brake my friend! Sounds good if you ask me, of course im a redneck

[Grabber]

Any ideas what this weird farting sound (as long as throttle is pressed) is when hammering in 3rd, 4th and 5th gears? Am I in the wrong gear or RPM - hard to image since I get this at when mashing it, but not at the red zone in the RPM range. For other explanations of the sound - it sounds like a tractor trailer letting go off the gas and getting that obnoxious exhaust note in a low gear (???).

 

Your insights will be valuable when the dealer tells me, "this is normal under various operating conditions and within thresholds".

 

Thanks,

 

 

What does it smell like ?

[Slabo]

You didn't happen to bring the dog with ya? Ok, Ok if it is detonation that is not good. Especially if its coming out of the dog.

[SmellSoGood]

I'm serious.

 

It's like there's a leak when pushing hard, as if air is causing something to flap. This is not easy to explain as you will find a connotation in every word I write

 

Anyway, the sound coming from the engine that I tried so hard to explain does not cause any shaking. Boost kicks in as normal.

 

No mods at all. I always use 93 octane.

 

What does detonation mean and what is the cause? Bad spark plugs already? Is this common?

[Rarecat]

Smells so goods complains of his car making a farting sound at max pressure....... is someone pulling our leg?

 

 

are ya hitting the rev limiter?

[bpmurr]

My car makes a farting sound after greasy pizza and some diet mountain dew..... never mind that's me.

[Torched10]

I'm serious.

 

It's like there's a leak when pushing hard, as if air is causing something to flap. This is not easy to explain as you will find a connotation in every word I write

 

Anyway, the sound coming from the engine that I tried so hard to explain does not cause any shaking. Boost kicks in as normal.

 

No mods at all. I always use 93 octane.

 

What does detonation mean and what is the cause? Bad spark plugs already? Is this common?

 

 

its uaully caused by bad gas, ie not really 93--are you using branded gas??But detonation sounds more like a sewing machine,and youd definitely feel a loss of power--weird haw you dont lose power--if you rev it at idle do you hear it

[2010KonaBlueGT]

Any ideas what this weird farting sound (as long as throttle is pressed) is when hammering in 3rd, 4th and 5th gears? Am I in the wrong gear or RPM - hard to image since I get this at when mashing it, but not at the red zone in the RPM range. For other explanations of the sound - it sounds like a tractor trailer letting go off the gas and getting that obnoxious exhaust note in a low gear (???).

 

 

Hmm.

 

Bypass valve stuck open?

 

Exhaust manifold leak?

 

Only at higher RPM suggests it is boost related. Possible leak between the blower and manifold? Boost bypass valve would be the first place *I* checked.

 

Can you isolate where the noise is coming from? Engine? Trans? Rear gear? Right side, left side, middle? (etc.)

 

 

Phill

[Son of GT]

I'm serious.

 

It's like there's a leak when pushing hard, as if air is causing something to flap. This is not easy to explain as you will find a connotation in every word I write

 

Anyway, the sound coming from the engine that I tried so hard to explain does not cause any shaking. Boost kicks in as normal.

 

No mods at all. I always use 93 octane.

 

What does detonation mean and what is the cause? Bad spark plugs already? Is this common?

 

 

Can you video tape the problem? That might help us help you.

[Slabo]

Can you video tape the problem? That might help us help you.

 

 

+1 if we can hear it that might help. Does it only happen is a certain rpm range? The rev limiter does kind of sound like that and is obvious to test. These things can be frustrating and hard to isolate sometimes. I was going to say pain in the ass but I figured you might be punned out by now.

[blkGT500nCA]

I would avoid wide open throttle driving until this situation is resolved.

 

+1 on video if possible. Otherwise I'd take the car to a dealer and go for a drive one of their mechanics.

 

(immature reply)

Maybe it just needs some Pepto-Bismol.

[SNKBT1]

Any ideas what this weird farting sound (as long as throttle is pressed) is when hammering in 3rd, 4th and 5th gears? Am I in the wrong gear or RPM - hard to image since I get this at when mashing it, but not at the red zone in the RPM range. For other explanations of the sound - it sounds like a tractor trailer letting go off the gas and getting that obnoxious exhaust note in a low gear (???).

 

Your insights will be valuable when the dealer tells me, "this is normal under various operating conditions and within thresholds".

 

Thanks,

 

 

Stay off the Rev Limiter.

[SmellSoGood]

its uaully caused by bad gas, ie not really 93--are you using branded gas??But detonation sounds more like a sewing machine,and youd definitely feel a loss of power--weird haw you dont lose power--if you rev it at idle do you hear it

 

 

 

Thanks for the serious reply. I could see how my inquiry could be considered a joke to some, except for a few.

 

I use branded gas - Primarily Hess and BP because they are en route to work and home. I tried Sunoco 94 and it still happened. At idle I hear nothing. Revving it sounds normal as well. As for your sewing machine example, it's much louder and raw sounding (more than the normal engine sound). Another way to explain the sound is as if the exhaust manifold was no longer in place. It gets pretty loud under the hood when this rev matching sound is emitted.

 

The only way is to video tape this.

[2010KonaBlueGT]

Thanks for the serious reply. I could see how my inquiry could be considered a joke to some, except for a few.

 

I use branded gas - Primarily Hess and BP because they are en route to work and home. I tried Sunoco 94 and it still happened. At idle I hear nothing. Revving it sounds normal as well. As for your sewing machine example, it's much louder and raw sounding (more than the normal engine sound). Another way to explain the sound is as if the exhaust manifold was no longer in place. It gets pretty loud under the hood when this rev matching sound is emitted.

 

The only way is to video tape this.

 

 

Check where the head pipe connects to the exhaust manifold.

 

I'm wondering if maybe backpressure under throttle is separating them at the seam from loose nuts on the studs, opening up a crack and you're hearing the exhaust note..

 

This is strange......

 

 

Phill

[blkGT500nCA]

You've got a 2010, take it to the dealer.

[NordicShelby]

You've got a 2010, take it to the dealer.

 

+1 this is what I thought makes the most sense.

[SmellSoGood]

Everyone! Thank you for your inputs and possible places to look. I will check it out tomorrow more closely.

 

The sound only happens at higher RPM, but not always. Never at low RPM. More obvious in 4th and 5th gear when mashing throttle past 3/4. If you ever recall (can't imagine anyone has), I have ranted how I feel this car is slow. Maybe this problem is the cause and I yet to feel why the heck I bought a 50k car with 540hp if my 2002 S4 bi-turbo is faster (butt-seat dyno talking).

 

From a sound placement, it's hard to tell because of the driver orientation compared to how close the engine is behind the firewall. To me it sounds from passenger side center of engine. I'll look more closely with light and get underneath (no suicide jack), just ramps. There are no leaks from what I can tell - no drips. No splatter, dirt, or residue on any component or wiring. I'll get the ancient Canon MiniDV camera and tape it to the inside of the engine bay and try to upload something to YouTube or similar by end of weekend.

 

Here is a thread I opened earlier today of a thought I have. Can anyone tell me what an EGR module does and why mine is rusty?

 

Detonation would sound more like a "plink", but this sounds airy and flappy with deep throat header attitude. OMG. No puns intended. Again, no mods and tunes. No smoke from exhaust or smells. Just pretzel bits and stickers in the backseat from the 3 year old and my commute each morning.

[2010KonaBlueGT]

 

Here is a thread I opened earlier today of a thought I have. Can anyone tell me what an EGR module does and why mine is rusty?

 

 

The Exhaust Gas Recirculation (EGR) circuit is a NOx control device.

 

NOx is created when combustion temps exceed 2500d F. The EGR valve only opens on light cruise (NOT at idle or WOT) on a fully warmed up engine and allows inert exhaust gasses (primarily Nitrogen with traces of argon/xeon/neon/etc) to be recirculated into the combustion chamber thereby "diluting" the combustion chamber gasses. Inert gas does not burn like Oxygen does so in essense, it is taking the place of air/fuel and having the effect of cooling the combustion chamber temps to get them down below 2500d F again.

 

The symptoms of a inoperable EGR system are light pinging at mid-throttle, light cruise conditions because of the increased combustion temps. At WOT the combustion temps are reduced by a richer/cooler AFR.

 

You can check and see if your EGR tube from the exhaust to the valve is rotted out. I have seen that but the noise just acts the same as a exhaust leak (as that is really what it is). You valve is rusty because the heat from exhaust gas is hot and over time burns off the paint leaving bare metal to oxidize (rust).

 

Caution: If your EGR circuit is working correctly the EGR valve will be EXTREAMLY hot to the touch. It will burn the skin off of your finger before you even realize you were burned. Don't ask me how I know.....

 

 

HTH,

Phill

[SGT/SC#0471]

" obnoxious exhaust note " Thats the jake brake my friend! Sounds good if you ask me, of course im a redneck

 

 

 

 

I like it too, and the decell sound from a uncorked Shovelhead is like a symphony to me bbbbbrrrrrraaaaaaaappppppppppppppppppppppppppppppppppppp.

[2010KonaBlueGT]

Here is a thread I opened earlier today of a thought I have. Can anyone tell me what an EGR module does and why mine is rusty?

 

 

I had a thought. Pull the vacuum control hose off of the EGR valve and see if you noise is still there.

 

Report back to me here when you try that. I may have a clue as to what it is.

 

Also note your power level with the hose removed. Get the engine hot and allow it to make the noise before disconnecting the hose. Don't turn the engine off, just unhook the hose and stick a golf tee into the open vacuum line then go try to get the noise to happen.

 

 

Let me know what happens,

Phill

[9599svt]

I had a thought. Pull the vacuum control hose off of the EGR valve and see if you noise is still there.

 

Report back to me here when you try that. I may have a clue as to what it is.

 

Also note your power level with the hose removed. Get the engine hot and allow it to make the noise before disconnecting the hose. Don't turn the engine off, just unhook the hose and stick a golf tee into the open vacuum line then go try to get the noise to happen.

 

 

Let me know what happens,

Phill

 

 

This will throw your check engine light on just so you know but after you connect it back up and go through three full warm up, cool down cycles it should go back off again.

[interceptor]

Sounds like the supercharger is dumping pressure like in an overboost condition. This would also explain power loss.

[2010KonaBlueGT]

This will throw your check engine light on just so you know....

 

 

 

Yep, it should. That's not what I'm trying to deduce though.

 

 

Phill

[SmellSoGood]

SOLVED!!!

 

The farting sound (prolonged) during 3/4 throttle in 3rd, 4th and 5th gears at RPM range 2000 - 3500 (varying speeds obviously) was due to a shitty stock resonator. Something was causing this fluttering sound; either a leak or the baffles inside were creating the annoying sound. Not knowing what it was I already had my eyes on the JLT air filter and FRPP resonator elimator. Just replacing the stock air filter with the JLT did nothing, so I awaited delivery of the FRPP resonator. Swapping that out totally eliminated the fluttering/farting sound.

 

I'm a happy camper knowing it was not knock/detonation, plugs, or faulty fuel injectors. Now I feel the power that I was lacking (hence the complaining I had in several posts saying this car was slow and my bi-turbo Audi had more butt-dyno). I was wrong! Too bad I only figured out this fix 8,500 miles into owning this car. Can't wait for the next 75k!

 

Tom

[mullens]

I don't know why Ford put those dumb resonators on in the first place. Oh, you don't want people to know it's supercharged??

[Torched10]

I don't know why Ford put those dumb resonators on in the first place. Oh, you don't want people to know it's supercharged??

 

when they announced the car one thing they talked about was sound deadening,both the exhaust and the SC---sounded pretty dumb to me then,and still deos now