Strange noise

[jandyp]

OK, this is weird, but here it goes. I have a 2010 Mazda5 Touring, about 34,000 miles. For the last month or so, I've noticed a very high-pitched tone when I start up my engine in the mornings, back out, and go to work. The noise is clear, consistent, and super high-pitched...like it's a dog whistle or something. It is a grating sound, like the test of the emergency broadcast system that you hear on the radio, but higher pitched.

It gets weirder. When I accelerate the noise stops. When my foot is off the accelerator, the noise resumes. After the car "warms up" five minutes or so after driving a bit, the sound seems to disappear.

Any thoughts? Should I bother to take it in? I have very limited mechanical knowledge, but it is a very unusual sound. Maybe I'll even try to record it and post an audio file here.

 

[Davicho]

When did you buy your MZ5? You may still be under bumper to bumper warranty.

 

[phunky.buddha]

Fuel pump?

 

[jandyp]

When did you buy your MZ5? You may still be under bumper to bumper warranty.

Bought it in late Dec. 2010. That's why I'm thinking about taking it in, as I'm just under the wire for the B2B warranty. Fuel pump is a good thought...that could be.

 

[thaxman]

High-pitched whine off-throttle until warm up? I have a low-pitched grind on-throttle until warm up. Wanna bet they are related?

 

[Donewood]

Possibly Drvie Belts. Open the hood and check for burning rubber smell... When engine stopped check if belts are glassed or cracking. Definatly take advatage of your B2B and stand your ground, they may try to pin it on you. Report it then if it takes a year to sort out it's still against the warranty. I've heard of some of these issues comming up on "Flood Cars" any weird electrical problems?

 

[jandyp]

Thanks

Possibly Drvie Belts. Open the hood and check for burning rubber smell... When engine stopped check if belts are glassed or cracking. Definatly take advatage of your B2B and stand your ground, they may try to pin it on you. Report it then if it takes a year to sort out it's still against the warranty. I've heard of some of these issues comming up on "Flood Cars" any weird electrical problems?

Will check for the burning smell tomorrow and take a look at them. Haven't had time to take it in yet, but will plan on it next week.