Heater Core Issue or ???

[NorthStar1]

It doesn't do it all the time but about three or four times per month I get a sucking/high pitched whine/harmonic sound coming from the area behind the passenger side dash/under the hood. This occurs immediately after I turn off the engine.

It's under warranty and I need to get a couple other warranty items resolved but thought I'd see what opinions are out there that could be causing this...or if it is an issue at all. Thanks in advance for any constructive comments.

 

[KeithP]

It doesn't do it all the time but about three or four times per month I get a sucking/high pitched whine/harmonic sound coming from the area behind the passenger side dash/under the hood. This occurs immediately after I turn off the engine.

It's under warranty and I need to get a couple other warranty items resolved but thought I'd see what opinions are out there that could be causing this...or if it is an issue at all. Thanks in advance for any constructive comments.

It’s more likely freon pressure neutralizing in your A/C system. Not your heater core. If you’re at the dealer for other services I’d mention to them. They can check for a leak and make sure your system is fully charged. I doubt there is anything wrong. I’ve heard what your describing on most vehicles I’ve owned and even my house unit.