When it is cold outside (below freezing), I get a noise like a bearing squelling from the front of the motor on my 04 LC. It is definitely coming from something being driven by the serpentine belt. About 6 months ago, I did my timing belt with a new water pump and timimg belt idlers. In the last month, I did the serpentine idler and the tensioner pulley assembly, but the noise is still there. The colder it is outside, the longer the squel lasts-about two or three minutes at idle when it is around 20 degrees.I'm thinking it might be the fan bracket bearing or the alternator. Any ideas appreciated. John
Bearing Noise at front of motor, 04 LC
- Thread starter jward
- Start date
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belt tensioned correctly??Hit it with belt dressing[bar of soap will do] to see itf it is ths belt itself
FYI, I've driven or ridden in a number of 100 series and they all made that sound on sub-freezing days. Not sure what causes it.
mine has done this the last few days.. never when above 28*F but its been under 20*F this week and it has squealed for the first few minutes every time I started..
scottm
SILVER Star
I fought with that, records from the previous owner indicate they also did. I just did my timing belt, haven't heard the squeal yet since then with temps in the teens. I didn't replace my serpentine belt pulleys or the fan bearing, but they all seemed solid.
jward - I'm assuming you have a new serp belt from when you did the other work. Sounds like the belt is just a little tight when cold. Have you inspected tension while cold before starting ?
I would not put belt dressing on a relatively new belt. It might stop the squeal but create slipping at the pulleys.
I would not put belt dressing on a relatively new belt. It might stop the squeal but create slipping at the pulleys.
scottm
SILVER Star
Belt dressing is supposed to increase belt grip, I've used it in automotive and industrial applications for 30 years and never seen it cause slipping at the pulleys. Or is this something new, like maybe serpentine belts are different with belt dressing?
In the old days mechanics would dribble soapy water on the belts while the engine was running to remove oil, so they could determine if a noise was the belt slipping. Just a diagnostic. Very messy though, don't stand in line with the belt.
In the old days mechanics would dribble soapy water on the belts while the engine was running to remove oil, so they could determine if a noise was the belt slipping. Just a diagnostic. Very messy though, don't stand in line with the belt.
a lot of time the noise from belts can also be crud built up in the grooves of the serpentine pulley... so when people spray stuff on it helps clean that out...
belt spray etc is a temp solution (one that can last a while though) to fixing the real issue... check your tension, and also the pulleys for play etc...
belt spray etc is a temp solution (one that can last a while though) to fixing the real issue... check your tension, and also the pulleys for play etc...
Guys, I think I was referring to a different sound. Its not a belt squeal. Its more of a bearing whine. Sounds more like the whine of a supercharger.
If definitely bearing type whine and not belt squeal then it needs to be found...
There is a tensioner pulley on front of engine of my 2000....and it has an adjustment for spring tension and sometimes when cold it will make a little noise. You might try to put a tad more on the spring and then start back up to see if that gets it.
also, i would not discount the waterpump again unless you are positive they used toyota parts and have full faith in the mechanic. I would get one of the engine stethascopes or a wooden dowel and being careful not to get it into moving parts see if you can isolate the sound.
I had an idler pulley on my FJ60 go bad and do this....simple fix but drove me nuts and was very thankful it was not something else.
There is a tensioner pulley on front of engine of my 2000....and it has an adjustment for spring tension and sometimes when cold it will make a little noise. You might try to put a tad more on the spring and then start back up to see if that gets it.
also, i would not discount the waterpump again unless you are positive they used toyota parts and have full faith in the mechanic. I would get one of the engine stethascopes or a wooden dowel and being careful not to get it into moving parts see if you can isolate the sound.
I had an idler pulley on my FJ60 go bad and do this....simple fix but drove me nuts and was very thankful it was not something else.
- Thread starter
- #11
update
thanks for all the input. When I did the timing belt this last summer, I replaced the timing belt idlers, serpentine belt and water pump, all with Toyota parts. When this noise started this winter, I replaced the idler pulley and tensioner pulley, neither of which had any effect on the noise. I have tried several things to isolate the noise. With a stethoscope, I have ruled out the alternator, power steering pump and a/c. The stethoscope indicates the noise is from the area of the idler pulley or fan bracket. This morning, I removed the serpentine belt to make sure that the noise was not a timing belt issue. With the serpentine belt removed, there was no noise whatsoever. When the belt was off, I soaked it in hot soapy water, rinsed it and put it back on while it was still warm. My thought was if the belt was slipping because it was hard from the cold, putting it back on while warm would identify that as the source of the noise. Again, the noise was unchanged. Which brings me back to where the stethoscope tells me the noise is coming from-the idler and the fan bracket. It can't be the idler since the noise is identical after replacing the original idler a month ago and since both the original and the new idlers are butter smooth. As to the fan bracket, I am reluctant to put in a new one since that bearing also feels super-smooth with no play whatsoever. I am now wondering if it might be the fan clutch since the noise definitely has a thermo-quality and only exists for the first few minutes when the engine starts in the morning. Today, when the noise stopped, I shut off the engine and felt the fan clutch and it had certainly warmed up. Tomorrow morning, before startiing the engine, I am going to warm up the fan clutch with a heat gun to see if that takes care of the cold start-up noise. If the noise is still there, I think the only thing left is the fan bracket. Again, thanks for the help.
thanks for all the input. When I did the timing belt this last summer, I replaced the timing belt idlers, serpentine belt and water pump, all with Toyota parts. When this noise started this winter, I replaced the idler pulley and tensioner pulley, neither of which had any effect on the noise. I have tried several things to isolate the noise. With a stethoscope, I have ruled out the alternator, power steering pump and a/c. The stethoscope indicates the noise is from the area of the idler pulley or fan bracket. This morning, I removed the serpentine belt to make sure that the noise was not a timing belt issue. With the serpentine belt removed, there was no noise whatsoever. When the belt was off, I soaked it in hot soapy water, rinsed it and put it back on while it was still warm. My thought was if the belt was slipping because it was hard from the cold, putting it back on while warm would identify that as the source of the noise. Again, the noise was unchanged. Which brings me back to where the stethoscope tells me the noise is coming from-the idler and the fan bracket. It can't be the idler since the noise is identical after replacing the original idler a month ago and since both the original and the new idlers are butter smooth. As to the fan bracket, I am reluctant to put in a new one since that bearing also feels super-smooth with no play whatsoever. I am now wondering if it might be the fan clutch since the noise definitely has a thermo-quality and only exists for the first few minutes when the engine starts in the morning. Today, when the noise stopped, I shut off the engine and felt the fan clutch and it had certainly warmed up. Tomorrow morning, before startiing the engine, I am going to warm up the fan clutch with a heat gun to see if that takes care of the cold start-up noise. If the noise is still there, I think the only thing left is the fan bracket. Again, thanks for the help.
scottm
SILVER Star
Could you try running it without the fan to see if it's the fan clutch? I didn't replace my serpentine bearings, would like to hear that it wasn't them, otherwise I'll be worrying 'till my next belt job. It didn't look easy to replace the fan bearing in the fan bracket, not sure if I'd have to order a new fan bracket. Looks pricey.
FWIW my alternator bearing made a sound like a mini-turbo spooling up...unfortunately I wasn't getting any intake boost from it 
. It was always louder when cold and less so when warm although the whine never went away until I swapped in a new alt. And once in hand the bearing was obviously worn.
Our alternators sit rather low and accumulate trail crud...all the worse if you've been swimming with your rig
.
May not be your culprit but something to check if all else fails.
. It was always louder when cold and less so when warm although the whine never went away until I swapped in a new alt. And once in hand the bearing was obviously worn.Our alternators sit rather low and accumulate trail crud...all the worse if you've been swimming with your rig
.May not be your culprit but something to check if all else fails.
- Thread starter
- #14
The alternator is dead quiet on the stethoscope. This morning I pre-heated teh fan clutch before starting the motor by pouring some warm/hot water on the clutch housing. I then started the motor and instead of two or three minutes of squealing I got about 15 seconds.
My conclusions for my cruiser are: 1) From the large number of posting on various sites describing the same start-up squeal, there is a wide-spread issue with toyotas in cold weather. 2) as others have described the problem, you could calibrate a thermometer based on the morning when you get the squeal, compared to when you don't. Mine kicks in at temperatures below 30 degrees (and probably down to about 20 degrees during the night). 3)the predictability of when you'll get the squeal to me suggests the fan clutch since by design the fan clutch is temperature sensitive, whereas bearings are not precisely termperature-sensitive. When the clutch is cold, it allows the fan blade to freely spin around the shaft. With this free spinning and high degree of slipping, the squeal is generated. As the clutch warms up, there is less slipping and the squeal goes away. The fan clutch theory is also supported by the fact that the squeal goes away alot quicker if you immediately drive after starting, as opposed to letting the cruiser idle until warm. The higher engine rpm's more quickly warm up the fan clutch and the squeal goes away quicker. 4) a stethoscope is invaluable at ruling out sources of the squeal. It might not be able to pinpoint the exact source of the squeal where two possible sources are close to one another or where you can't directly touch the area because it is a moving, rotating part (like the fan clutch), a stethoscope is a whole lot more accurate than your unaided ears at identifying the source of noise.
Again, thanks for all the help. John
My conclusions for my cruiser are: 1) From the large number of posting on various sites describing the same start-up squeal, there is a wide-spread issue with toyotas in cold weather. 2) as others have described the problem, you could calibrate a thermometer based on the morning when you get the squeal, compared to when you don't. Mine kicks in at temperatures below 30 degrees (and probably down to about 20 degrees during the night). 3)the predictability of when you'll get the squeal to me suggests the fan clutch since by design the fan clutch is temperature sensitive, whereas bearings are not precisely termperature-sensitive. When the clutch is cold, it allows the fan blade to freely spin around the shaft. With this free spinning and high degree of slipping, the squeal is generated. As the clutch warms up, there is less slipping and the squeal goes away. The fan clutch theory is also supported by the fact that the squeal goes away alot quicker if you immediately drive after starting, as opposed to letting the cruiser idle until warm. The higher engine rpm's more quickly warm up the fan clutch and the squeal goes away quicker. 4) a stethoscope is invaluable at ruling out sources of the squeal. It might not be able to pinpoint the exact source of the squeal where two possible sources are close to one another or where you can't directly touch the area because it is a moving, rotating part (like the fan clutch), a stethoscope is a whole lot more accurate than your unaided ears at identifying the source of noise.
Again, thanks for all the help. John
FYI,
I was just reminded that my gs430 produces the same noise when super cold.
I was just reminded that my gs430 produces the same noise when super cold.
Is it identified?
Have you done anything further, like removing the fan bracket to check its bearing, or tested the fan clutch ?
Have you done anything further, like removing the fan bracket to check its bearing, or tested the fan clutch ?
I've noticed the same whine on my recently purchased 100. Temps have just recently gone around 30 degrees the past week.
My whine goes away whenever the front passenger seat is empty. Weird. 
Figured I would keep relevant noisy belt / pulley issues in this thread.
Trying to diagnose a slight chirp in my engine bay.
Problem
- Slight chirp develops after engine runs for 20-30 seconds on cold mornings. This is a new symptom that developed after some recent repairs done by me and listed below. Sprayed some water on belt ribs with no change in noise.
Troubleshooting
- All pulleys check out, they spin smooth with no noise
- Fan clutch has no wobble or leaks and spins pretty smooth for half a revolution, then seems to free up slightly, then smooth again. Spins maybe 1/4-1/2 turn.
- Serpentine belt is OEM with not many miles
- Tensioner pulley and tensioner assemble recently replace, new OEM. The new pulley was much smaller than original and I didn't like that, Toyota and other threads here seem to agree it's not an issue.
- Idler pulley replace with new OEM
- New PS Pump
Possible solutions
- Maybe belt got a little greasy, thinking of just replacing it.
- I need to remove serp belt to ensure this isn't an issue within the timing belt system
Any other ideas?
Trying to diagnose a slight chirp in my engine bay.
Problem
- Slight chirp develops after engine runs for 20-30 seconds on cold mornings. This is a new symptom that developed after some recent repairs done by me and listed below. Sprayed some water on belt ribs with no change in noise.
Troubleshooting
- All pulleys check out, they spin smooth with no noise
- Fan clutch has no wobble or leaks and spins pretty smooth for half a revolution, then seems to free up slightly, then smooth again. Spins maybe 1/4-1/2 turn.
- Serpentine belt is OEM with not many miles
- Tensioner pulley and tensioner assemble recently replace, new OEM. The new pulley was much smaller than original and I didn't like that, Toyota and other threads here seem to agree it's not an issue.
- Idler pulley replace with new OEM
- New PS Pump
Possible solutions
- Maybe belt got a little greasy, thinking of just replacing it.
- I need to remove serp belt to ensure this isn't an issue within the timing belt system
Any other ideas?
