Good afternoon, first off thank you for setting this up, I just found it today and I've been watching your content going on 6 years now. I've asked this during your live before, but I wanted to include all the details, and this seems to be the place to do that.
2012 Toyota corolla S with 200,281 miles, I purchased it from a single owner at 130,951 miles (purchased October 2023) it made it across country from florida to Nevada with absolutely zero issues. IV stayed on top of my maintenance with oil changes, brake replacements,plugs, even transmission filter replacement.
I replaced the alternator and belt at 168,437 miles(July 2025). Both done as a precaution before that country long trip. This set up has the manual tensioner on the alternator, which at one point was not tight enough. At the time I was dealing with the high pitch belt squeak, especially if I turned on the AC while turning and going from a parked position.
The problem seemed to go away. But, it then did it again. And it seems to be only an issue when Im going from reversed/park to moving forward. If I'm turning when I start rolling, it will squeak. If I roll the windows down as Im starting to move, it will squeak. As soon as I turn the AC completely off, it will stop, and I can turn my AC back on.
I have checked the tensioner and it is tight, as is the belt. The belt is also still in excellent condition. I have zero codes, and I've never had any codes outside of the generic "maintenance required" light, which comes on automatically after so many miles driven. I do however have a brand new icon digital/touchscreen OBO scanner from harbor freight that does live data, and I'm itching to use it.
Anyways, I thought I would drop this question here and see what your thoughts are. Thank you again for all you've done and do. You have taught me many life long lessons through your videos, all which have helped me learn how to take care of my vehicles.
I don't know why the links don't work for you. We all use the lemon manual here. But I turned them into images for you:
(click to enlarge)
https://imgur.com/a/corolla-belt-5JcrlwA
@imperator I'm not sure if this is the proper way to respond, I'm new to this style of communication. But, thank you for the pictures, also maybe the link just didn't work because I'm using my phone? Regardless, I have to inform you that I always purchases the paper and digital Hayne manuals for my vehicles. I read it when I did my belt replacement and realized I missed the important instructions on doing the tensioner. Which your pictures also showed me the proper way. Very rookie mistake on my part, but it happens and we learn! But now the squeak is gone! So thank you thank you! I'm coming back here with any questions I have.
Glad it helped. Haynes manuals are great for basic stuff (I purchase them myself), but there is simply no replacement for factory service manuals. Luckily for everyone, they are easily available at the link I posted. And they work nicely on my smartphone too. Happy driving!
@imperator so I was able to get their sister site to work, charm. I just scanned it for brake information and your not kidding. The compete step by step guide is amazing. Thank you for showing me that, I'll definitely be making use of it.
Charm is what we used before lemon came along. It's the same idea, except it only covers up to around 2014 models.
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there are various domain names for accessing lemon. Maybe one of the other ones will work for you.
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They also have a notice posted that says:
(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)
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I use Firefox both on my phone and laptop
especially if I turned on the AC
AC compressor putting tension on the belt
If I'm turning when I start rolling, it will squeak.
power steering pump is putting tension on the belt
If I roll the windows down as Im starting to move, it will squeak.
alternator is putting tension on the belt
So it seems like you have a general belt problem. Probably slipping. Did you buy a reputable brand?
Here is Toyota's procedure for adjusting belt tension, including torque specs:
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Note that there are four bolts to check, and the tension needs to be re-checked after running the engine for 5 minutes.
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Here is the procedure to check proper belt tension, including deflection specs:
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https://lemon-manuals.la/Toyota/2012/Corolla%20S%2C%20Automatic%20Trans/Repair%20and%20Diagnosis/Engine%20Mechanical/Mechanical/Engine%20Mechanical%20%28Overhaul%29%20%28Service%20Information%29%20%282ZR-FE%29/Drive%20Belt/On-Vehicle%20Inspection/On-Vehicle%20Inspection/
@imperator thank you for such a quick response. My initial thought when I had the turning incident, was my power steering going bad, and then when the AC did it, I thought oh no. That one too. And then I realized maybe I have a bad belt? Even though it was new, the car never did any of this until I changed the belt. I realized I purchased the belt from advance auto, and the first purchase wasn't the right one. Maybe it's just a bad quality belt? I was unable to open your links, but I will look up those instructions and follow them accordingly. Thank you again, I will be doing my transmission filter and fluid tomorrow, also new pads and rotors, so I'll make sure to check my pulleys and the belt tension while I'm there working. I will update when I have completed that. Thank you again!