Alright guys question. My cobalt started making a popping noise today under acceleration. Wasn't enough to spin tires but mild acceleration. Coming from front driver side. Put it up on stand and spun tires back and for and it makes a small pop I don't know how much noise is normal for it. It does have the LSD in it. Any ideas of what could be causing the noise? Please help

 

Like machine gun popping noise under boost?

 

Ehh i guess if I accelerate hard it will sound that fast but it comes from trans area

 

Oh I didn't read that right. That sounds like ur wheel bearing is shot, I had same issue, more like a clicking card in bike spokes sound on mine though

 

mine is like hard pop under mild to heavy acceleration

 

Any way u can make a video with the sound? Could be a few things

 

How do I post a video on here??

 

https://www.youtube.com/watch?v=x0Hw...ature=youtu.be

 

I did it for u, same way u post it in message

 

That sounds pretty bad, i'd investigate the mounting points of the engine and subframe, also control arms. Has any recent work been done on the car? That sounds like something big is loose and moving under torque to me.

 

No recent work done. Check all suspension parts and all of them are solid. But yes something is moving/ popping when the turbo starts to spool. Only gear it wont do it in is first gear

 

I'm going with wheel bearing. sheering wheel shake, traction control going out, noise, all fixed when I changed mine. but do some more checking just in case, those bearings arnt cheap.

 

Here's an update just launch the car like I would at the track in first gear at 2K turn had traction control off. Launch the car spun tires and all no popping noise until second and third gear when turbo started to spool

 

Sounds like a boost control/knock issue to me. In 1st gear it goes by quicker and the load is lower so you don't hit it, but once it has a chance to load up fully and build boost it's either overboosting and knocking (possible poor quality gas? Recent fillup?) or the wastegate is fluttering or something like that. It's hard to say via just the video as the sound never translates the same. Can you duplicate it when parked?

 

I just got it to do it in first gear with traction control on. I tried to brake boost test still did it while braking. And it only makes the sound when driving i couldnt get it to make the noise when it was in the air.

 

Ok if it does it while brake boosting, you may have to lift the car and run it in the air and brake boost, while someone listens for the location of the noise.

Is it a light/metallic popping, like a handful of coins in a metal bucket, or more clear like a pack of firecrackers going off?

 

More like firecracker from DS

 

Had a thought about this issue at work the other day. I've seen this happen when an axle starts to strip splines, it only pops when there's enough torque to move it but it sounds like what the vid shows.

If you can support the front end of the car and run it in gear, brake boost until it does the noise a little bit and see if it sounds like it's coming from the trans or the intermediate shaft bearing area, then remove the axle or shaft and look at the splines.

 

Figured it out its the injector seals. They have a tendency to go bad, and cause the machine gun like popping noise! It is the lost of compression. Which is why it does it only when turbo spools enough to creat small amounts of boost

 

Makes sense. I'm trying to think back, I remember a local kid having his seals failing on him one sunday when we were out racing, I don't recall the specifics but I know you could hear it from outside the car. My memory is not what it used to be

 

I was in the middle of a race when mine went as well

 

Oh my! sounds translike to me...

 

glad you figured it out. That would freak me out. I get a wierd little chirp noise randomly from the Front driverside wheel well?? cant really tell if its under the hood on in the wheel well. Its while rolling at low speeds or shifting. Im thinking the u-joint making a wierd click noise that sounds like a chirp.

I also now have clunking in the suspension over bumps at low speed. Everything feels solid when I lift the car up. Not sure what that is either. people suggest its the steering rack being loose. Everything on the internets wants to point towards sway bar end links, bushing, CABs.

 

Yea i have the weird clunk noise at low speeds as well and cant figure it out at all either! No play in the wheels or tie rod ends. Sway bar links don't make a sound when I hit them.

 

Cabs most likely