Start up noise?
Thread Starter
Drifting
Joined: Jan 2006
Posts: 1,554
Likes: 158
Start up noise?
2015 C7 3LT Z51 A8. Great car but one thing is bugging me. After a night in the garage and I first start the car in the AM there is easy to hear noise. Sounds like fluids circulating in the front dash area behind the gauge cluster. I have air conditioning and fan off but still hear it. Sounds a bit like my old C5 when I turned on the heater on I could hear the fluid circulating. Oddly, after the car warms up this noise goes away almost completely. Even though I think I have the heating and air condition systems off maybe they circulate fluids anyway. Any thoughts?
Burning Brakes
Joined: Jun 2014
Posts: 981
Likes: 157
Many modern cars have the coolant flowing continuously through the heater core, probably to save money and possibly to avoid the chances of leakage associated with a valve. Turning the heater on/off is done by changing the airflow with dampers in the ductwork.
Drifting
Joined: Sep 2014
Posts: 1,267
Likes: 119
From: Bellevue WA
2015 C7 3LT Z51 A8. Great car but one thing is bugging me. After a night in the garage and I first start the car in the AM there is easy to hear noise. Sounds like fluids circulating in the front dash area behind the gauge cluster. I have air conditioning and fan off but still hear it. Sounds a bit like my old C5 when I turned on the heater on I could hear the fluid circulating. Oddly, after the car warms up this noise goes away almost completely. Even though I think I have the heating and air condition systems off maybe they circulate fluids anyway. Any thoughts?
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Thread Starter
Drifting
Joined: Jan 2006
Posts: 1,554
Likes: 158
C7s, no sputtering at startup for me. Noise sure sounds like fluids circulating. Sound seems to come from driver side dash area. It is not a big deal as it goes away as the car warms. Just trying to identify it. Maybe it is the power brake vacuum as billeee mentioned.
Thread Starter
Drifting
Joined: Jan 2006
Posts: 1,554
Likes: 158
OK, talked with the Service Advisor at local Chevy dealer that services the most Corvettes in this area. He said that the evaporator core pressurizes and circulates freon at start up. Process is normal and circulating fluids are more audible at cold start. Some lines are located behind driver side dash. Does not matter if it is a remote start or push button start. Nor what the driver settings are. System is going to pressurize at start up as a normal function. Thanks to those who responded. I think mystery is solved.
Same here for my 2016