Serpentine Belt Replacement Interval? (1 Viewer)

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Can anyone reccomend a resonable mileage interval for serpentine belt replacement?

I've got an unpleasant squealing noise that's coming from the front of the engine. The noise manifests on cold starts (below 50ºF), the colder and more humid, the worse the noise. I'm not yet sure what the cause of the noise is.

I've owned my LC for about 18 months. Current mileage around 148k. I looked through my service records and I don't have confirmation that the serp belt was changed, but the timing belt and water pump was done at 93.5k miles in 2014. It seems to me that the belt -should- have been changed at that time.

I have a mechanic's stephoscope but I'm a bit reluctant to lower that long rod down near the spinning fan and running belts. Is there any other way to diagnose and determine the source of the noise?
 

GTV

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With the engine idling spray a little lube around the center of each of the pulleys. If/when the sound goes away, you've found your problem.
 
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First you take the belt off and do a cold start to confirm that the noise is indeed originating from the serpentine belt. Then spin all the pulleys to see what you see and hear. The answer might be obvious and you might find more than one pulley in distress. It's easy to remove the belt and to reinstall it.
 

flintknapper

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First you take the belt off and do a cold start to confirm that the noise is indeed originating from the serpentine belt. Then spin all the pulleys to see what you see and hear. The answer might be obvious and you might find more than one pulley in distress. It's easy to remove the belt and to reinstall it.

^^^^

This. Should always be standard procedure before anything else.
 

Mkstinatx

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Can anyone reccomend a resonable mileage interval for serpentine belt replacement?

I've got an unpleasant squealing noise that's coming from the front of the engine. The noise manifests on cold starts (below 50ºF), the colder and more humid, the worse the noise. I'm not yet sure what the cause of the noise is.

I've owned my LC for about 18 months. Current mileage around 148k. I looked through my service records and I don't have confirmation that the serp belt was changed, but the timing belt and water pump was done at 93.5k miles in 2014. It seems to me that the belt -should- have been changed at that time.

I have a mechanic's stephoscope but I'm a bit reluctant to lower that long rod down near the spinning fan and running belts. Is there any other way to diagnose and determine the source of the noise?
It’s possible when they changed the timing belt they did not change the pulleys or the tensioner. On mine the dealer did not change the water pump. I bought all the parts on Amazon and changed out everything. Mine was quiet after everything was replaced. But now my alternator pulley or power steering pump is making noise. My 2006 LX470 has 270,400 miles.
 

Mkstinatx

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Can anyone reccomend a resonable mileage interval for serpentine belt replacement?

I've got an unpleasant squealing noise that's coming from the front of the engine. The noise manifests on cold starts (below 50ºF), the colder and more humid, the worse the noise. I'm not yet sure what the cause of the noise is.

I've owned my LC for about 18 months. Current mileage around 148k. I looked through my service records and I don't have confirmation that the serp belt was changed, but the timing belt and water pump was done at 93.5k miles in 2014. It seems to me that the belt -should- have been changed at that time.

I have a mechanic's stephoscope but I'm a bit reluctant to lower that long rod down near the spinning fan and running belts. Is there any other way to diagnose and determine the source of the noise?
The belt and heater Ts should be replaced at the 90k service or if you see any cracking or wear on the belt.
 
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First you take the belt off and do a cold start to confirm that the noise is indeed originating from the serpentine belt. Then spin all the pulleys to see what you see and hear. The answer might be obvious and you might find more than one pulley in distress. It's easy to remove the belt and to reinstall it.

Thanks for all the replies! I'm assuming the water pump is directly driven so by removing the belt I'd only be loosing alternator, power steering and A/C. Is that correct?
 
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Thanks for all the replies! I'm assuming the water pump is directly driven so by removing the belt I'd only be loosing alternator, power steering and A/C. Is that correct?

Yes, water pump is on the timing belt. Good idea to find a belt diagram or make one before you start.
 

flintknapper

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Timing Belt Route:

Timing belt 2UZ FE.jpg



Serpentine Belt Route:

Serp Belt Route.jpg
 
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Portland, ME
I made one, see below.

Yesterday the damn thing made noise on a cold start. After driving about 50 minutes on the highway it was completely quiet. Once it gets cold it starts making noise again. Anyone have any suggestions?

Going to try the stethoscope this morning and see what I can determine.

I tried searching for threads on the pulleys, but now all I get is this thread. Anyone have links to threads about pulley replacement?

Serpentine-Belt.gif
 
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A great test of drive (serpentine) belt, is getting it wet. New OEM belts don't squeal when wet. You'll find a sticker on underside of hood with belt routing. Remove belt, with a 14mm socket and long 1/2 ratchet works very well. Turn the tensioner's 14mm nut CCW (this is only left hand thread bolt on a 100 series) to release tension on belt.

Testing idler or tensioner pulley bearings, is supper easy. Stethoscope is very helpful. Acid test is once belt removed.

Parts:
Serpentine Belt, I use only OEM. Perfect and great quality.

Idler pulleys I just replace with OEM. They are pricey but last the longest.

Tensioner pulley bearing R&R
 
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I did the stethoscope test and it was inconclusive. The vibration of the noise was picked up by the entire engine, which mean that you heard it to some degree through the stethoscope when touching the hub of each pulley.

However - I did get the impression that the noise was stronger on the passenger side of the engine. The pulley beneath the power steering (alternator) seemed to be a source of noise. But looking from above I could not see a non-moving part on the pulley to test. It seemed that the center nut was turning with the pulley.

Still wondering why the noise is so inversely correlated with temperature. Even after many hours of cool-down, the pulley/belt is not as noisy on a 2nd start-up as it is on the morning cold start. Current morning temps here are just above freezing.
 
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I did the stethoscope test and it was inconclusive. The vibration of the noise was picked up by the entire engine, which mean that you heard it to some degree through the stethoscope when touching the hub of each pulley.

However - I did get the impression that the noise was stronger on the passenger side of the engine. The pulley beneath the power steering (alternator) seemed to be a source of noise. But looking from above I could not see a non-moving part on the pulley to test. It seemed that the center nut was turning with the pulley.

Still wondering why the noise is so inversely correlated with temperature. Even after many hours of cool-down, the pulley/belt is not as noisy on a 2nd start-up as it is on the morning cold start. Current morning temps here are just above freezing.


Go back to the advice given earlier. Generally speaking the belt should be removed so you can spin and test all the pulleys, if they free spin or sound scratchy they may be to blame. If all pulleys check out you should check for proper belt tensioner operation. If that all checks out the belt should be replaced.
>> If you think the issue lies within the timing belt and components pop off the serpentine belt and see if the noise goes away.
 

flintknapper

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OP is hung up on 'temperature' and not listening to sage advice to REMOVE the darn serpentine belt and spin each and every pulley. This would confirm or eliminate several possibilities. But I guess we are going to go the long way around?
 
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OP is hung up on 'temperature' and not listening to sage advice to REMOVE the darn serpentine belt and spin each and every pulley. This would confirm or eliminate several possibilities. But I guess we are going to go the long way around?

It's possible they are not comfortable removing the belt ? Maybe pop down to Toyota and see if you can get them to diagnose
 
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OP is hung up on 'temperature' and not listening to sage advice to REMOVE the darn serpentine belt and spin each and every pulley. This would confirm or eliminate several possibilities. But I guess we are going to go the long way around?

Not ignoring your advice... it's cold, dark and raining and I don't have a garage. So removing the belt will have to wait.
 
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Not ignoring your advice... it's cold, dark and raining and I don't have a garage. So removing the belt will have to wait.

Oh, that's too bad. You know, Mainers have a reputation, perhaps undeserved, of being very stout hearty folks - maybe because it's cold, dark and raining 8 months out of the year. But let us know how it goes next summer.
 

flintknapper

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Not ignoring your advice... it's cold, dark and raining and I don't have a garage. So removing the belt will have to wait.

'When' you do it is up to you of course. But take the belt off. Actually....you don't have to completely remove it. Just take the belt off of the tensioner then lift the belt by hand off of each pulley as you spin that component. That way you don't have to reroute the belt.

Easy to do. Takes a 14mm socket or wrench. Just press down on the tensioner bolt (its a left hand thread).

Wait for better weather conditions if that is best for you.......OR:

1. Cold (remedy... warm clothing)
2. Dark (remedy... Flashlight)
3. Raining (remedy...umbrella, pull under parking garage/other) ;)

Hope it turns out to be an easy fix for you and not something like a Fan Bracket.

Let us know what you find.
 

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