I had that noise lol. Mine OEM tensioherner fell apart after removing it, which I replaced with the updated LNF tensioner. This is a noise which as best I can describe is....

1. From the backside of the engine on the passengers side front

2. Does not appear to be coming from the s/c?

3. The noise is constant.....is their at startup and revving the engine.

4. The noise gets more noticeable as rpms increase.....it is related to rpm.

5. Noise still there if the clutch is pressed in......it only lessens as rpms fall.

Supporting details.

Oil is the correct level.....with synthetic (not mobil however....called g-oil) and has some restore thrown in. Have had this for several hundred miles and no problems. Again has the updated tensioner from GM....OEM part. Car is not throwing any codes, nor am I noticing any driveability problems....no loss of power or anything.

Please help point me in the right direction!

Thanks!

 

Loose flywheel? Do you have an aftermarket.one? I always had Fidanza flywheels come apart and cause this.


That's my guess.

 

What kind of noise is it? Ticking? Whirring? Ect....

Have you ruled out all of your belt driven pulleys?

If it is a ticking it could be a small exhaust leak (likely from the flex pipe).

 

Thanks all. So far I have considered an exhaust leak. I should mention.

1. I am stock flywheel afaik. Im the second owner so I assume with only 56K its stock.....no slippage.

2. I am running a ZZP midlength......no flex pipe. Also on BWoody solid mounts....I considered something rattling...???? Im fairly used to all the rattles from the vehicle b/c of the mounts....this is definitely new

Thanks and keep the input coming please!

 

pull the valve cover and check the cams for wiped lobes or a failed follower and inspect the chain check for tightness and it could be the new tensioner has failed

 

remove the belt and if the noise stops then it is one of the pulleys

 

good suggestions i will see if i can pull the vc tommorow....check the chain for tightness. I will check the noise with the belt off at the shop (on lift) to see if its still present....also will check my coupler too.

only concern about a bad tensioner is this. it doesnt sound like a tensioner....and the noise came after its replacement by a hundred miles or so...related?

 

my guess is the serpintine belt tensioner.... fixed my problem

 

Cobalt SS/SC 07 Engine Problems - YouTube

Update.....sounds like that. Could it be I have a bad tensioner?

 

That sure sounds Ike the timing tensioner is bad.
How's the belt tensioner look when the car is running,bouncing up and down at all?

 

I will call monday to the dealership and see about getting another one. this one might be bad. easy to try. i will drive to my rents house and bum the truck until i get it have fixed.....dont wanna drive it unless i have to.

the tensioner (belt)....it moves a lil bit.....ii scoped it (long screwdriver on various things) and its hard to pinpoint. sounds like its from the front of the engine itself...which lends the chain tensioner theory credit. the actual belt tensioner itself isnt noisey.

thanks all.

 

There was at least 3 or 4 revisions on the tensioner (cam chain) so make sure they order you the latest and greatest!

 

i got the one from ced. rather the p/n and got it at a local dealership. it looked nothing like the og oem unit......which actually fell apart on me.

this time i will have the v/c off and will make sure its installed to torque spec (not me just ham fisting it) and chain tensioned properly.

thanks

that video i linked to, sound like a tensioner to you? to be honest im a bit chuffed. i thought for sure i had that licked!

 

Is the tensioner hydraulic itself? Or is it pumped up by outside pressure? I saw a hole in my new one of the bottom and wondered...lol. Just a random thought.

 

Sounded like a bad tensioner.

 

UPDATE: Got the the new tensioner in from the local GM place. This one does not move at all! The other one had play in it where the actual tensioner would move up and down. Me never seeing one figured oh well its supposed to be like that......this one wont budge so....bingo! Thanks all for the help and will install tonight with confirmation of repair!

 

Probably an exhaust leak at the header/dp connection, i had the same problem. And the ony fix i found was to get a remflex gasket. definitely worth it

 

Ok. Replaced tensioner with new one (OEM GM). Tightened all connections on exhaust. Retorqued solid mounts (settled and retorqued...hella better ride now), inspected bolts for tightness on belt tensioner and tigntened.

Noise still there!

Could it be the S/C coupler? I havent found a real good video showing how it sounds. Help please!

 

Think it might be the header flange bolts? Read a couple people with similar noises have that as the cause.....i have a zzp mid lenght which had some bolts hard as hell to get to....?