I remember there being a forum for troubleshooting, but can't find it. Mods, feel free to move this.

I have an 07 S2k and I am having some interesting problems with it.

I get this strange hissing noise, when driving my car sometimes. Nothing I do seems to have any effect on it, I turn the wheel, brake, clutch change gear, throttle position, nothing changes it, except it seems like it sputters a little when i got over short bumps in the road. It almost sounds like steam escaping from a small tube.

The temp gauge never moves, the car feels normal and drives normal. It usually happens on the highway but sometimes on streets too.

Then there is another issue. when I turn left at slow speeds I hear what almost sounds like a light metal on metal machining sound. It could be the same noise and it sounds different at slower speeds. Today I was turning left and the VSA light and the VSA off triangle came on.

What the heck? I took the car to get the diff oil changed at the dealer a few weeks back but this just started happening on Monday so I am not sure it's related. What do you guys think?

 

The hissing noise is most likely a vacuum leak. Or you're talking about the air pump kicking on and off. The air pump won't make the car sputter over short bumps, though.

The temp gauge never moving might be an issue with either the CTS, the or the wiring between it and the ECU or between the ECU and the gauge cluster....or you have a bad thermostat and the car will never heat up. Or someone removed the thermostat and the car will never heat up.

Or maybe there's a problem with the cooling system along with a bad sensor...which would explain the hissing noise (over heating coolant noises) and sputtering (over heating makes it run rich).

Any of those could be correct...or it could be something totally different. You might want to have the car inspected.

Not sure what's going on with your VSA. Maybe they damaged a wheel speed sensor? Maybe the brake shield is contacting the rotor causing the scraping sound.

Your car has some issues. Was it modded when you got it? Did it seem well taken care of?

You really should have it inspected somewhere competent if you don't know how to diagnose it yourself.

 

Sorry, let me explain that better. The car down't sputter over bumps. The hissing noise sputters.

And when I said the temp gauge didn't move I meant that it wasn't overheating. Not that it was always displaying in the same spot cold or hot. It warms up like normal and stays there regardless of the hissing noise.

The wheel speed sensor sounds like an interesting thought. I'd like to get it up on some blocks and take a look at it myself but I don't have a garage anymore.

Can you tell me more about the air pump?

 

The air pump is a device that blows air into the intake stream to add oxygen content to the cat at idle when the car is running rich. It usually happens on cold start up or just at random times when the car runs rich. It does it only at idle as far as I know. It's an electronic pump inside the bumper.

 

That doesn't sound like this then, this noise seems to happen more often when the car is warm and on the freeway. Vacuum leak sounds possible. I guess I should take it back in to the dealer where I got my work done and see if they can spot the problem.

 

Vacuum leaks are easy to find. You can use some throttle body cleaner and spray it along vacuum lines and ports while the car is idling normally. If the idle goes up, you just found a leak. Plug the hose back in when you find it. Maybe the car had an intake on it before you bought it and the previous owner didn't button things up good enough.

 

Is the hissing sound present when you're idling? If not, could it be a lightly dragging brake pad? Just a thought...

 

@ b serious The car does have a K&N intake on it. It was on the car when I bought it about 30,000 miles ago.

@ Greg W It's so sporadic, it would be tough to get it to recreate it at idle. But if it were a brake pad, the problem would change if I stabbed the brakes while I was driving. I've tried that and there is no change in the sound.

 

Stock exhaust? Maybe there's a leak there.

 

I thought they deleted the air pump on 06+.