amgrobaspach

first problem with my C32, last few days I've been noticing the car to have a high idle in park and Neutral sometimes 1500rpm and then it will lower eventually to 1000rpm.

Aslo hearing " Hisssssss" or "sssssssss" air sound coming from top of engine bay near my wipers . It's not too loud , I can only hear it if I'm outside of the vehicle though.

No Check Engine Lights on. Also Previous Maintainence from Dealer shows New transmission installed, torque converter adjusted, supercharged repairs as off 2012.

I scheduled a premium oil chsnge and transmission flush for this Friday.

kbob999

Sounds like a vacuum leak to me, probably somewhere around the throttle body at the back of the engine.
There is a 5/8" hose that comes into the back of the supercharger on the left side, which could make this noise.
Or possibly something with the purge valve vacuum line. There are a few vacuum lines around the engine which could cause this.
Also a line for Engine vapors at the bottom of the throttle body. Hard to see this last one without taking the intake off.
Wiggle the hoses around while the car is idling and see if you can find where it's coming from. Anything broken will need to be repaired.

amgrobaspach

I was thinking vacuum leak as well after doing some research on google. So say I find the leak in a Hose, do I just replace the hose or do I have to replace the intercooler and supercharger as well?

kbob999

99% it's just a hose. Find it and fix it.
You won't need a supercharger or intercooler unless they have failed. This does not sound like a failure of those parts at all.

Hey - are you in Denver area now? I'm just South in Parker. If you want to meet up, I could scan your car and help you out. Only cost you a 6 pack

amgrobaspach

Here is a pic, Noise "Ssssss" sound coming from where I am touching with my finger.

amgrobaspach

Throttle Body is what I narrows down to what is making the noise, which explains my rough idle. found a OEM 200$ rockauto

or could it be that it's just needs to be cleaned. A partner of mine said it might be stuck open.

amgrobaspach

LoL sounds great, but I'm not there yet. Just took a job offering in Denver and will be relocating this fall. Thanks for offer, I will update you when I set up camp.

kbob999

See the hose on the firewall ahead of your hand? Wiggle that and see if the his changes. Then look at other hoses in the area.
Your TB is OK, otherwise the car would not run. Get a friend who knows this stuff better, otherwise you are throwing money and parts at it.

amgrobaspach

Thanks and I totally agree with you, I have a budy who is a service tech II at Cadillac who will be taking a look at it to properly diagnose it, and hopefully we're able repair the problem as soon as possible.

I'll keep you guys updated , thanks for the reply.

Gramma_Benz

Actually I had issues with high idle, and bouncing idle and it was my TB. I still drove it daily as well. Had to get it rebuilt.

Hidden codes will point the way, a professional scan tool will pull them.

Good Luck!

Amg1988

hey guys, I'm curious in what those 2 small vacuum lines on the supercharger are for, the "U" type one is completely missing on my supercharger.