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Mystery Whine in 2014 Equinox

5K views 8 replies 6 participants last post by  christopherlompoc 
#1 ·
Hi all,

I've got a mystery whine that has stumped me and mechanics for almost a year. A bit of background, I have a 2014 2.4L Equinox (Flex Fuel) with 181k miles (it was a fleet vehicle prior to our purchase). Despite the mileage it runs very well, I change the oil every 3k miles at minimum and am diligent about all other maintenance.

About 9 months ago, I started hearing a chatter/whine while idling, as soon as I go above ~1k RPM the noise stops. I initially replaced the belt tensioner since the serpentine belt was due anyway, but no change. Using a stethoscope I can hear it clearly on the engine near the coolant hose above the alternator, next to the engine mount bolts. I can't tell if it's resonating from somewhere else, or this is actually the source. The alternator doesn't seem to be the cause, and is putting out the right voltage. It isn't a consistent noise, as you can hear in the video, and isn't synced to RPM.

It's a bit louder when idling on a hill, happens in all weather conditions, and happens whether or not the AC/air is on.

Very recently the car has starting idling a bit rougher, despite an oil change, but I'm not sure if this is related. The video below is a good indicator of what I hear all the time. Any help would be much appreciated!

https://streamable.com/6i5bc
 
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#2 ·
The 2.4 has been known to need new timing chains and guides on high mileage vehicles.
Just a guess not knowing it's service history.
 
#4 ·
Just to eliminate any accessory drive concerns, AC, alternator, idlers or water pump; you could temporarily disconnect the belt and run it briefly. If the noise is still there, it's internal.

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#9 ·
Sounds like you have some really old coolant in there... Debris in the cooling system is like one of leading causes of pump failure. Depending on what pump u have there should be a weep hole positioned towards the top of the motor... Probably some coolant pooling there... If you do have the older style pump it's possible for coolant to find its way into oil. Worse case scenario it will fail at the worst possible time, take out the whole balance shaft chain overheat and seize the engine.
 
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