Jrg77

Greetings,

I just bought it Saturday. I would like to get a good engine check on it. What should I ask the mechanic to do? I'm thinking a compression and leakdown test. Are there any turbo-specific test that be performed?
Also is it possible to hear a turbo going bad? It seems I hearing something like unlubricated bearings when I first start it, then it gets quiet. Is the boost sound different from a bearing sound? It picks up power nicely between 2500-4000 rpm then seems to struggle. Never had a turbo car before so I am learning here.

Thanks for the help!

blueLNFftw

iTrader: (16)

Uh. Should have done this before you bought the car...

Jrg77

That's water under the bridge, isn't it?

kzak104

iTrader: (1)

Drive it till something blows up.

Maybe post a video of the bearing sound you speak of. Its probably just the vvt actuators charging up with oil.

How much boost is it making.

Jrg77

The highest I've seen is 17.x. Didn't know about the VVT actuators. It did sound like something missing oil. Do they only do that at startup?

LNFwagonSS

Any turbo car owner should have their own boost leak tester. Do some searching on here to find out how to make your own tester and how to do the boost leak test. Only thing to do with turbo is check for excessive shaft play, which would cause the blades to scrape the housing which you would obviously be able to hear. Good used turbos are a dime a dozen nowadays so replacement won't cost too much.

Mr Mall Cop

iTrader: (1)

Welcome to Cobalt land, Once you enter there's no escape.

tomj77

iTrader: (2)

Is it a bearing with no oil sound or is it a massive sucking of air sound. The car has a cat warmup mode that sucks a lot of air and dumps fuel in to warm up cat. When I got my car everyone always commented that it has a bad bearing. I had to educate them. So find out if it's that. Start it up, don't touch the gas and see if it does it for a while, then next cold start, start it up and give it a rev and see if it goes away, if it behaves like I'm explaining, ur most likely hearing ur turbo sucking air for cat warm up .

Joe09SS

iTrader: (1)

Glad I tuned out the car warmup, who needs cats anyways?

Win

Shanedude

Yeah it makes people question sometimes the cat warm up is so loud.(k&n included)

And I have to let it finish or it'll be finicky. But it's all for the environment right.

tomj77

iTrader: (2)

Mine is turned off, no cat

exninja

iTrader: (1)

Did anyone ever make a "typical Cobalt SS/TC sounds" thread? There are quite a few unique sounds to this car. Most of us went through the freakout phase a number of times when buying our cars.

Some I can think of:
evap purge "monkey" banging on things in the trunk at stoplights
gear shifts clunking
low gear trans whining
HPFP ticking

tomj77

iTrader: (2)

Hey that's a good idea, if someone do it I'll make it a sticky. Include audio

Snail_SS

iTrader: (3)

Yeah everyone always asks me about that hpfp ticking

63 Nova SS

iTrader: (3)

I have none of those. Only sound I ever get is the sunroof squeaking from body flex.

kzak104

iTrader: (1)

if you dont have hpfp tick than you dont own an lnf

blueLNFftw

iTrader: (16)

Mine is so loud I think it's broken.

63 Nova SS

iTrader: (3)

Yeah it ticks, but it's really not loud after it warms up. Wish I could get the "cam lope" sound like the roller cam in the nova. I miss that.

09CobaltSS1

It's certainly possible. The car definitely won't be very happy, but doable none the less.. lol

SSlobalt

My car is stock right now. I can try to record the warmup on Saturday.

Terminator2

Can easily be done but will idle and run like crap right off idle as well. Trust me you do not want to do it.

63 Nova SS

iTrader: (3)

Yeah I know. I have always had v8 cars that had big cams. Love that sound but not practical on a cobalt.

09CobaltSS1

Is there an echo in here?

Terminator2

Is there an echo in here?

09CobaltSS1

Just bounced off me and stuck to you.

Eat that big guns!