Squealing Noise When Starting

[kap]

Mt 2001 RX300 makes a squealing noise when starting. It sounds just like slipping belts. I replaced both drive belts last year, and the noise decreased, but with cold weather returning, the noise has returned with a vengeance. The squealing only lasts about 5 seconds after starting, then abruptly goes away. It occurs most every time I start the enigne. I tried re-tightening the belts today, and adding a bit of belt dressing. With the inner fender trim off, when the engine was started, it sounded like the A/C compressor bearing may have been the cause of the squealing. Has anyone heard of the A/C compressor being the cause of a noise like this. Once again, the noise only lasts about 5 seconds and does not return under any conditions - only initial startup.

Thanks,

[lenore]

The AC belt probably needs to be tightened just a little bit more. If you can twist the belt more than 1/2 from it movement it is too loose. You should be able to twist it a little, but not a full 90 degrees.

[tjmc11]

The above reply is true. The only catch is that you do not have an adjustment bolt as in most vehicles. You actually have to pry the belt / pully back and then tighten the securing bolt once you have it pryed to the correct tension. This is a bit of a project just to access the belt area etc. I had the exact same symptoms so I can understand the frustration of starting your car and receiving the loud noise. Hope this helps. Email me @ tjmc11@hotmail.com if you need any pics or video on how to do it.

[artbuc]

The AC belt probably needs to be tightened just a little bit more. If you can twist the belt more than 1/2 from it movement it is too loose. You should be able to twist it a little, but not a full 90 degrees.

Lenore, I just posted a question re alternator belt tension then I found this thread. Could you elaborate? I'm not exactly sure what you mean. Thanks.

[lenore]

grab the belt on the half way point between the alternator and the next pulley and try to twist it 90 degrees from its normal motion. It you can turn the belt more than 90 degrees it is too loose.

[Amy Hernández]

My 2002 RX300 has been doing this for a while. I figured out that if I had everything on the dash turned off, and waited for a few seconds before turning the ignition all the way over, that it wouldn't do that. 

Well, it rained today and is chilly. And now it's making that awful noise even with me doing all of that. And it's not stopping after 5 seconds, so I've turned it off because it's LOUD. 

It sounds to me like a really squeaky belt that maybe got wet or something. 

My husband thinks it's a leak in the power steering pump. 

Any ideas?? 

[RX400h]

It could also be a bad pulley bearing or AC compressor.

[Amy Hernández]

Since it now does it when you turn the AC on (or just even the blower) "too soon" after turning the car on - or if you don't turn it OFF before turning off the car - I am thinking it MIGHT be the AC compressor. 

BUT.. how do you diagnose it to figure out FOR SURE what's causing the issue?

[daisyduke]

On 11/25/2007 at 4:43 PM, kap said:

Mt 2001 RX300 makes a squealing noise when starting. It sounds just like slipping belts. I replaced both drive belts last year, and the noise decreased, but with cold weather returning, the noise has returned with a vengeance. The squealing only lasts about 5 seconds after starting, then abruptly goes away. It occurs most every time I start the enigne. I tried re-tightening the belts today, and adding a bit of belt dressing. With the inner fender trim off, when the engine was started, it sounded like the A/C compressor bearing may have been the cause of the squealing. Has anyone heard of the A/C compressor being the cause of a noise like this. Once again, the noise only lasts about 5 seconds and does not return under any conditions - only initial startup.

Thanks,

Does it sound like its coming from the dashboard? Mine makes a weird noise from the dash usually when I turn air on. It goes away after a few seconds. 

[RX400h]

Take a look at this page:
Why is My Car AC Squealing and How To Fix It (carcarehacks.com)