[Louis Chevrolet]

I drove my car 30 miles home from the dealership with a new replacement battery yesterday. All ok.

Today, after 2 trips totaling 30 miles, a steady hissing, white noise is heard from the dash area. When I parked, the noise continued. Didn't matter if car was on or off. After a few more minutes parked, the noise went away. Ambient temperature was about 70 to 75 degrees. Battery was about 70% charged. Noise started back up when I started driving again. Air conditioning and heat and automatic climate control were all off.

My search on this forum tells me this noise is from coolant pump and coolant circulating. All 3 coolant reservoirs are slightly over full level.

Any suggestions on what to try or check? At a minimum I feel like I need to take another drive to see if the noise comes back?

 

[jreddington]

I drove my car 30 miles home from the dealership with a new replacement battery yesterday. All ok.

Today, after 2 trips totaling 30 miles, a steady hissing, white noise is heard from the dash area. When I parked, the noise continued. Didn't matter if car was on or off. After a few more minutes parked, the noise went away. Ambient temperature was about 70 to 75 degrees. Battery was about 70% charged. Noise started back up when I started driving again. Air conditioning and heat and automatic climate control were all off.

My search on this forum tells me this noise is from coolant pump and coolant circulating. All 3 coolant reservoirs are slightly over full level.

Any suggestions on what to try or check? At a minimum I feel like I need to take another drive to see if the noise comes back?

Sounds like a vacuum leak. Oh, yeah, no ICE .

Seriously, might be some residual air bubbles if the vac and fill wasn’t done thoroughly. They may make their way to the coolant reservoir so keep an eye out for the level.