Loud "farting" sound when accelerating

[Soules75]

Recently my truck started making what I can only describe as a startlin, loud farting sound while accelerating. It doesn't do it all the time, but once or twice a day..and it is LOUD! Here is a video I captured today on my way home from work. Any idea what the hell this is?

 

 

[Jsdirt]

Gotta change your Youtube settings - none of us can see it. It's private.

[SouthernSilveradoGuy85]

If it's only under acceleration I want to say maybe a motor mount.

[Soules75]

That is odd, just checked and the video is set to public already. Anyone else not able to watch it?

[DaveH71]

Sounds like the ABS actuating, can you feel the brake pedal pulsing during this?

 

Lightly rest your foot on the brake the next time this happens to feel if its pulsing or not.

[Rick H]

If you have a belt driven fan and a broken mount it could be the fan rubbing on the shroud

[Soules75]

Sounds like the ABS actuating, can you feel the brake pedal pulsing during this?

 

Lightly rest your foot on the brake the next time this happens to feel if its pulsing or not.

I don't think that's it actually. If I let off the gas it immediately stops. Sometimes it sounds slightly different than how it sounds in the video. I'll upload another shortly here.

[Soules75]

If you have a belt driven fan and a broken mount it could be the fan rubbing on the shroud

I have been running the AC since it has been hot lately. Today when it happened I turned the AC/fan off in the middle of the noise and it stopped. Not sure if it was coincidence or if it is related to the AC or fan. What exactly should I look for? Sorry, I am not good with this stuff.

[Jsdirt]

Vid is working now. Sounds like the fan hitting the shroud to me. Just look for evidence of that under the shroud, and on the edges of the fan blades. Get a good light so you can see.

 

Then, if you confirm that, you'll have to figure out why that's happening.

[Soules75]

I looked and don't really see any signs of scraping on the fan blades or shroud. It only happens once in a while when accelerating though...if it was the fan rubbing wouldn't it happen more regularly or frequently? I tried to wiggle the fan but it seems solid. I can't see anything that would potentially rub, but it did seem like a rubbing noise to be too and my first thought was maybe the fan was rubbing something. Hmm

[kstruckcountry]

I'd check motor mounts first

[Soules75]

I also found this sitting in my driveway right next to the driver side door the other day. Guessing t fell off the truck but can't figure out what it is or where it fell from. Probably not related to the weird noise, but thought I would post it...any ideas?

 

[Rick H]

Looks like the wire protector that goes into the door

[pickmeup]

It has been said a farting horse will never tire....A farting man is the one to hire. Now about a farting truck?

[Jsdirt]

I also found this sitting in my driveway right next to the driver side door the other day. Guessing t fell off the truck but can't figure out what it is or where it fell from. Probably not related to the weird noise, but thought I would post it...any ideas?

 

 

That's the rear bump-stop - it mounts to the frame directly above the pad on top of the rear axle.

 

Like everyone has been saying, if your motor mount is bad, the engine will lift under load, causing the fan to hit the shroud. That's usually the first sign that a mount broke. Sometimes you'll feel a "thud" when releasing the gas pedal - that's the engine slamming back down on the mount.