Front Squealing/Whining/Whistling when hot
 

Hey everyone,

Had this problem intermittently last year before it got cold over winter but it's come back with the hotter weather this spring (Atlanta, Ga). Really only notice it when I'm going on longer drives or sitting in traffic and it gets hot. I did the Georgia Dragon back in March and didn't notice it at all and it definitely got put through its paces.

It's definitely coming from the front and not near the engine bay. I've manually jumped the relays for both fans on low and high and confirmed they both run with no excess noise so that eliminated them as a potential problem unless they could be caused by actual heat and not just them running (coolant flowing through the system).

I've thought it may be the EVAP system somewhere, potentially caused by the heat causing pressure changes but the squealing seems louder than any videos I've seen of bad valves or canister and doesn't seem to change volume on either side of the car.

That leaves the fuel pump, I know this is something discussed often in topics on the forum but I've yet to find a good video/thread confirming that was the case. I'm also unaware if it can be caused intermittently based on temp so starting this thread in case y'all can confirm based on my video or it helps someone else later.

AC/Heater: off - Independent of fuel level - Independent of RPM's, speed, clutch engaged or disengaged.

https://youtu.be/CmuHsk32StE

PS - Already ordered new tires as well

Logically it sounds like a fan or fans. Could be the fan motor starts wailing only when it is hot. Perhaps jumper the fans and let them run with the car stationary and see if you get a noise after a certain time.

I would suspect the fuel pump. There's not much up in the front that can make noise besides it and the evap stuff you mentioned.

What I would do to try and diagnose pump...

Get the noise to happen like in your video (if you can). While its whining, turn car off. Then put key back in and turn to pos 2, but dont start the car. The fuel pump should run to prime the system. Do you hear the noise when the pump starts? You could also jump the fuel pump relay with the car not running (directions can be found on forum), and listen for noise when pump starts.

I have read of boxster fuel pumps making noise intermittently, and you mentioned it does it when warmed up which is why I recommend trying the test while you have the noise occuring.

Also, whats your gas level like when the noise happens? Most fuel pumps use the fuel for cooling, if low on gas and the pump is struggling/weak it can overheat when gas gets low.

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That definitely sounds mechanical. I doubt it would be the EVAP canister. Hmm. Doesn't really sound like the fans to me. I think GLImages has some good advice here, I'd do what he suggests. Definitely keep us in the loop as to what you discover.

Can you unplug the fans..when that noise starts jus to try and eliminate them,.??

I'm with elgyqc. It could be the fans. But to me it sounds like they're rubbing against something.
When's the last time the rads were cleaned? It could very well be some debris that the fan blades are rubbing against. Try cleaning them out. It's cheap, fairly easy, and it's something that should be done now and then anyway.

While it could be the fuel pump, usually a noisy pump makes noise all the time, it's not temp related. The fans, on the other hand, only kick on at higher temps. Try cleaning the rads first.

What does it sound like with the fuel door open and cap off?

Hello, what was the fault? I have the same problem

Help please