I've been getting a nasty sound from the engine when I start the car after its been sitting for a while. It doesn't do it all the time but it did it the last 3 days in a row when I left work.
It sounds like its running rough and loud for a few seconds after I start it and then it smooths out and runs like normal.
It sounds like there isn't any oil pressure or an exhaust leak or something. It sounds too rough to be belt or a pulley, almost like you can hear the engine internals growling.
Has anyone else had this kind of problem? Its a 2.4L Auto.

 

I don't have a 2.4

what I do have is the 2.2 and it makes this noise on startup too. i think it the cams not getting any oil till about 3 sec after i start the damn thing. And my oil life monitor is on 78% remaining. so it's still kinda fresh oil in it.

anyoe else know of this??

 

I'm going to take it in to the dealer pretty soon here but I'm afraid that its going to be one of those problems that they will try to claim they can't duplicate.

 

Its piston slap my 2.4 has the same noise on start up sence I had it new

 

I see the LS-1 engeneers worked on the ecotec too.

 

i have the same thing happen on start up and I have a 2.4 5spd

 

i have the same thing since new

 

it's a tapping right? alot of cars have it on start up. i believe it's the lifters. when the motor sits all the oil drains down into the oil pan as you know and then when you turn the car back on it takes a rew seconds for the lifters to pump up again. think of a car with solid lifters and the sound they make when you first start them up. they make one hell of a chatter.

 

I don't know maybe it is the lifters or piston slap but this is not just a minor ticking its pretty severe. It doesn't sound good at all. It immediately quiets back down after 1 or 2 seconds though and its normal.
By the way I do have a separate ticking noise which isn't that big of a deal while its idling.

 

My sister had this problem is because she was running 84 octane gas. Switched to 91 and it never happened again.

 

did this start only recently??? you live in Michigan right??? Has it been colder recently??? if so the oil is probably thicker on startup than in the summer so it may take an extra few seconds to get circulating.

 

i have this prob too and i dunno wat the hell it is but it only happens when the cars cold and been sitting like over night....im gonna be bringing my car downstairs to service tomm to have them check that out as well as my broken sunroof switch, pulsating brakes and cracking rocker panel molding...cars a month old.....

 

MikeyMo, Let me know what they say it is on yours,

 

If it only does it on startup and not under driving conditions or load...Im gonna say its oil related, a normal condition...if it does it driving or after the car had idled to op temp then i would be worried...

 

That makes sense to me, yes its only when you start it up and its been sitting. Otherwise it runs perfect. It hasn't generally happened after leaving it overnight for me, its more likely to happen for me after lunch or whenever it seems like I've driven it hard and then let it sit for 3 or 4 hours.

 

it's dry start alot of cobalt have that problem as well as the headlights leaking the dry starts a serious problem and if you car's under warranty chevy will most likely fix it. and also for ppl like me who are to lazy to take it if you just turn on the key to acc pump up the pedal a few time's it'll prevent it there really is a certain technique to gettin rite but it's work for me