I think I have either a valve train issue or a turbo going out. I was going to pick up pizza with a friend not getting on it or anything, he is a tech for GM and was the one to go inside and get the pizza, when he came out he stopped and was listening to the car. I asked him what he was doing he said there is noise coming from under the hood, so we limped the car back to the shop just incase it was anything major. So instead of eating he started looking at the car and it sounds like a box fan when the blades hit the plastic gaurd on the outside. It heard over the right rear of the engine. He has a stethoscope with a metal rod on it to listen and said it is noticable over the exausht cam but is really noticable over the turbo. Pull the valve cover and everything is still in tight clearance, and looked good. No issues like smoking or engine performance but looking to see if anyone has experienced with this, and before we pull the turbo to look at the wheels and things if anyone has suggestions.

 

is it a rapid clack clack clacking sound? bad wrist pin maybe? or some play in the main bering on the left side of the engine?? def sucks though! good luck figuring it out

 

What is a wrist pin? I will just get a vid. if I can

 

Why you're at it, get a video of your car with the muffler delete and catless DP. Trying to see if it's the sound I'm looking for.

 

Well I am trying to get the other vid to upload now. If it goes I will get one for you.

 

Thanks man!! I know there was someone awhile back who was supposed to make a video with his muffler delete and catless DP but never did.

 

http://www.youtube.com/watch?v=rXiTV5_7KWA

Here is the noise have to turn it up to here. it.

 

Direct Injection? sounds kinda rapid for it tho....

 

No its not the DI. You have to listen its kind of random and can here it real good at the end when the camara is pointed at the turbo.

 

That is unusual. The damn fuel pump, makes it so hard to distinguish what it is. I can hear it, it's almost a rattle type noise. Does the sound increase when you throttle it?

 

A little bit, but then the motor gets to loud to here or distinguish the differance.

The first upload of the muffler delete didnt succeed. I will try in a bit again, sometimes its my internet that gets all messed up. But I sent you a PM.

 

By increase do you mean the frequency or the loudness of the actual sound?

 

does the sound go away after you rev it a bit? can you hear it inside the cabin?

 

it gets faster, doesnt really get louder.

You can not here it in the car. Not real sure do to the exhaust if it goes away I am going to say it doesnt.

Here you go I dont want to rev it to much, do to the problem, revved to 4000-4500rpms.

http://www.youtube.com/watch?v=bFqsMa2RAsY

 

Thanks for that video and the one in the PM. I dont think it's too loud like some people do, I think it sounds just right. Not that you care, but here is what my Brothers SRT-4 sounds like with his catless DP with E-cutout.

http://www.youtube.com/watch?v=dYJPEseJIL0

http://www.youtube.com/watch?v=Ikt7qHFAQJA

 

I have wished that our cars sound like the srt exhaust since day one. I like the deep tone they have and also how you can hear there turbo so nicely

 

Yeah that's the extra displacement they have. A guy who lives on here and has posted about his 20G Cobalt, he now has a catless DP with cutout, and his isnt asloud as my Brother's SRT-4. I think with a cutout though you would be able to hear our turbo too.

 

any update on this noise?

 

It almost sounds exactly like my 5.0 Mustang did when I had a leak in my header.New gasket and tightened it up,and problem solved.Are all of your your exhaust manifold bolts tight?

 

That noise coupled with your +20 STFT sounds to me like your cam driven high pressure fuel pump is going out on you. It has what looks like a valvespring and lifter inside. The spring could be broken or the cam may be broken.

 

There thinking it is a hydrolic lash adjuster. Which sits on the other side of the valve spring under the cam. Going to change oil tomarrow to see if it will allow it to pressure up if not replacing them on the exhaust side. Today I actually put the stock airbox with the stock filter back on and the stft was at 0 and the ltft was at -1.

 

sounds like a spring/valve problem