3.6L Pentastar Screeching W/Engine OFF

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That is a common sound on many new cars these days. The Chevy Malibu, Hyundai Sonata, Dodge Challenger and Charger are all cars off the top of my head that have this documented noise. I haven't heard what actually causes it. Some theories on the R-1234YF refrigerant pressure expansion, the radiator cap, or the keyless access receiver. Doesn't seem to be an issue though.

My guess is the R-1234YF pressure expansion, these noise complaints started appearing on cars that use the new ac refrigerant it seems. Just my guess!
 
Some cars will do an EVAP test when the engine is off and a amount of time passes. The HVAC system shouldn't make funny sounds when the car is not running with a stopped compressor, some cars don't have compressor clutches but will use a solenoid to vary compressor displacement depending on HVAC load.
 
All of my cars make random noises when they are not running, sometimes as I approach with the fob. My TDI's sometimes will have the cooling fans run for up to ten minutes. Obviously in the regeneration phase when I parked. The noise the OP has is unlike anything I have heard on my Pentastar '14 model minivan.
 
My 300 makes a noise like that sometimes, usually within 5 minutes after I shut it off. It's pretty quiet though. Everything still works, maybe it's the circulation door moving?
 
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Both my Challengers made a screeching noise and so does my Charger, but none did it with the engine off. In fact they could only be heard when the engine was at WOT...

In my case the source of the screeching turned out to be my wife.

Not surprisingly, the screeching went away once I stopped taking her for test drives.
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As for this screeching, IDK...sounds like one of those surprise scenes in a horror movie.
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Is this a new noise or has it always made it? Agreed it could be a test of the evap system.
 
Originally Posted by dishdude
Is this a new noise or has it always made it? Agreed it could be a test of the evap system.


I have never heard it before. It didnt do it about 3k miles ago when I changed the oil last. I though the neighbor was running a grinder when I was filling the washer fluid. Walked to the garage door and heard it behind me. Narrowed it down to the area of the engine I held the phone at to record it.
 
What good is this forum if every time someone asks a question the only responses they get are bashing the brand?
 
Originally Posted by dishdude
What good is this forum if every time someone asks a question the only responses they get are bashing the brand?

Well I think the self evident answer is that the forum becomes a pretty bad place to ask a question about an FCA product with a quality concern.

Now, if there's all these people that are doing it, then at some point you need to ponder, even if it's only to yourself, whether or not the group is on to something...

One way around the whole topic is for FCA to produce such high quality cars across their entire lineup that the public has no other choice than to say:

Originally Posted by NearlyEveryResponsibleDadEver
Man, I gotta get me one of those FCA products! They're just so darn dependable. My teenager can just thrash the thing nearly to death and it just keeps starting every morning and I can still trust it to get the kid to school.

Until that day comes, people will post topics about their late model Chargers making screeching sounds nearly a hour after being turned off and, more importantly, I think FCA will continue to bear the yoke of the quality reputation they've earned.

Cheers!!!
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The Mopar booster club used to meet every week. The problems started almost immediately as everyone knows that Mopar owners are always bad guys and swing a large pair wherever they may roam. The Toyota club fellas tried to sneak into our get togethers almost every week. We ex-filtrated them fairly quickly what with their mama's riding shotgun and their panty lines showing above their low riding jeans. The club was eventually dissolved when one Toyota driving imposter was overcome with testosterone fumes and had to be transported by his sister to the nearest whole foods to recuperate. RIP Mopar club of Badazzes.
 
Originally Posted by Imp4
Originally Posted by dishdude
What good is this forum if every time someone asks a question the only responses they get are bashing the brand?

Well I think the self evident answer is that the forum becomes a pretty bad place to ask a question about an FCA product with a quality concern.

Now, if there's all these people that are doing it, then at some point you need to ponder, even if it's only to yourself, whether or not the group is on to something...


It's how it's received, which actually played out like clockwork in this thread.

Literally 2nd post in this thread:
Originally Posted by buddylpal
That is a common sound on many new cars these days. The Chevy Malibu, Hyundai Sonata, Dodge Challenger and Charger are all cars off the top of my head that have this documented noise. I haven't heard what actually causes it. Some theories on the R-1234YF refrigerant pressure expansion, the radiator cap, or the keyless access receiver. Doesn't seem to be an issue though.

My guess is the R-1234YF pressure expansion, these noise complaints started appearing on cars that use the new ac refrigerant it seems. Just my guess!



Which everybody completely ignored and the anti-FCA trolls showed up and then the pile-on begins. That's how it ALWAYS goes, even if its just a basic question about how somebody likes their vehicle, somebody's sister-cousin from the hills of Tennessee, her uncle-dad's first wife's father from the Hinterland once had a Dart, and it didn't have a big block, so it was a pile and nobody in that entirely branchless family tree ever bought another Chrysler product again.

Comparatively, there's a thread about a Toyota with a transmission that shifts like a tweaker on meth and "it's all fine" it's just "buggy software" Toyota will take care of you or "that's unusual my 1982 Corolla was perfect, Toyota is the best".

The direction the threads take are COMPLETELY different. It's not because the FCA topics are comparatively awful, it's because you have the same group of soiled knickers sliding in and turning it into the monkey cage at your local zoo.
 
Check the PCV valve. Some are building up pressure and released pressure goes past oil cap. Easy way to check is pull oil cap and see if excessive pressure when removed after shutdown. I know mine makes noises after it is shutdown but that is normal as ac motors reset to closed position but normally heard inside. Only other thing I think of is ac is overcharged so when shutoff it releases excess pressure.
 
Where is the noise coming from? In car, under hood, under the car? It all happened so fast. At first sounded like starter not engaging but not loud enough, and that was before reading.
 
Please don't reply if you have nothing to offer except arguing

Several posts were removed as off topic trolling.

Next time will have topic locked, and time away given.
 
Originally Posted by KrisZ
Sounds like a servo motor to me. While I never heard this type of noise from my 15 Grand Caravan, my Mazda 3 will make a similar type of noise after shortly after being shut off from the drive by wire throttle body.

Yeah, sounds like a solenoid or motor (and not unusual). I expect its the system running a purge or post shut-down task, such as opening the TB to vent post operation gases or similar. I expect there are all sorts of protocols that vehicles are scheduled to operate that we aren't aware of.
 
It's coming from the driver side of the motor. Near where there is a polly for the serpentine belt. It did it at no specific interval for about an hour after I shut the car off. It was any where from 1 to 4 times a minute for about an hour after parking in the garage
 
I've had vehicles that had fans running or some other device but nothing ever screeched or made a loud noise.

It doesn't sound normal. If it is normal then it's not right.
 
Sounds like electronic noise. Noisy relay, rectifier, servo motor like suggested above, etc.

Like said, try to pinpoint the component. Can pull fuses to see which makes it stop.
 
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