Slight squeal and burning smell with high rpm

[Inoahguy]

I'm having an issue with my 2002 sr5 automatic that is starting to worry me. When I'm very conservative with my acceleration and speed, everything is fine, but the minute I get about 30% into the gas pedal, I hear a slight squealing noise. Then about 60% into the gas pedal it suddenly switches to a higher pitch of squeal and slightly noticeable burning smell with the windows down.
And in cases where I'm passing on the freeway and really need to get into the accelerator and my transmission down shifts into 4k or more RPM, the sound gets even higher, almost inaudible and the small is strong even with the windows up.
I checked the belts and they seem fine, although this has been happening since before I changed them last but has gotten worse recently.
I know that the catalytic converter can cause a sulfur smell under heavy load which I doubt this is. If anyone has any experience or ideas of how to tackle this, please shoot as I'm about out of ideas.

 

[thecole1098]

I'm having an issue with my 2002 sr5 automatic that is starting to worry me. When I'm very conservative with my acceleration and speed, everything is fine, but the minute I get about 30% into the gas pedal, I hear a slight squealing noise. Then about 60% into the gas pedal it suddenly switches to a higher pitch of squeal and slightly noticeable burning smell with the windows down.
And in cases where I'm passing on the freeway and really need to get into the accelerator and my transmission down shifts into 4k or more RPM, the sound gets even higher, almost inaudible and the small is strong even with the windows up.
I checked the belts and they seem fine, although this has been happening since before I changed them last but has gotten worse recently.
I know that the catalytic converter can cause a sulfur smell under heavy load which I doubt this is. If anyone has any experience or ideas of how to tackle this, please shoot as I'm about out of ideas.

Could be the idler pulley for the AC compressor belt. Try taking the pulley off and see if you notice any roughness when spinning it by hand. Both the squeal and burning rubber is a sure sign that a belt is slipping and since you just replaced them, I'm gonna bet on that idler.

 

[mtbtim]

I'd recheck the belt tensions on all 3 belts and then start listening with a mechanic stethoscope. Have somebody help you by revving the engine while you listen in different areas trying to narrow down the origin of the sound. If you can't locate the noise at any of the pulleys (alternator, power steering, AC and AC idler pulley or the fan bracket, listen to different areas behind the timing cover because one of your idler pulley might be the culprit.

Here's a link to a stethoscope I've bought and used with success to locate a noise on an engine.

https://www.amazon.com/gp/product/B0015DLMOO/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

 

[Inoahguy]

Could be the idler pulley for the AC compressor belt. Try taking the pulley off and see if you notice any roughness when spinning it by hand. Both the squeal and burning rubber is a sure sign that a belt is slipping and since you just replaced them, I'm gonna bet on that idler.

I'll try that, thank you!

 

[Inoahguy]

I'd recheck the belt tensions on all 3 belts and then start listening with a mechanic stethoscope. Have somebody help you by revving the engine while you listen in different areas trying to narrow down the origin of the sound. If you can't locate the noise at any of the pulleys (alternator, power steering, AC and AC idler pulley or the fan bracket, listen to different areas behind the timing cover because one of your idler pulley might be the culprit.

Here's a link to a stethoscope I've bought and used with success to locate a noise on an engine.

https://www.amazon.com/gp/product/B0015DLMOO/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Thanks for the link! I think my father in law might have one I can borrow in the mean time. I appreciate your help!