Noise coming from timing belt system

Hey guys,

A loudy noise (WIIIIIIIIIIIIN) is coming from inside the timing belt cover. It is linked with the RPM of the engine. Anybody have an idea of what could it be?

 

My guess would be either the idler pulley or water pump.

 

Sure it's the timing belt? May be the water pump. You can remove the fan belt and spin the water pump to see. Also, see if there is play in the water pump shaft side-to-side or top-to-bottom with the belt removed. A lot easier to diagnose the water pump before you start opening the engine...

 

On a V6 engine the water pump pulley is invisible with the timing belt cover on. The timing belt drives the water pump pulley. Removing the fan belts does not affect the water pump.

If the vehicle has over 90.000 miles on it I would suspect the water pump is going out and I would replace it along with the timing belt.

 

Which engine do you have? 3.4L v6 or 2.7L 4 cylinder?

Water pumps on the v6 usually don't make a bearing noise when they fail. They just start leaking. There are a couple of bearings behind that cover tho.

 

Thank you for the reply!
Sorry it's a V6 3.4L and it have at least 200 000km on it.
I didn't notice any leaking but I'll keep you in touch!

 

Yesterday I took a look at my "old" water pump. It had 88K miles on it. The pulley showed no play, but when I turned it I could hear a slight scraping noise at one particular point in the rotation. Also, there is a deposit of crap coming out of the weep hole where the bearing is, indicating a leak has started.

 

Usually from what I hear. But seems its becoming more comon for them Not to leak. Or show signs of leaking that you cannot see. Because with mine it didn't show and was convinced it was an internal timing belt pulley. But WAS in fact the water pump.

Same thing with mine. Along with the scraping and a wobble. I turned it after removing and it was still tight. But the shaft had been bent or the bearing was out of whack, and was wobbling around scraping against the casing. It was so tight though so it mistve been bad for a while. Seeing as I let it go too long too, it just went out even faster at that point once it started and eventually locked up on me.

Op you need to get this taken care of asap. If you are tearing it down at all just to take a look, might as well go all the way and do it all. Timing and belt and water pump kit from eBay seller aircabinman.

 

here's a video. I am now suspecting the alternator bearings...

 

Edited: Rewatched your vid a few times..Can't tell what noise you're referring to. I hear a loud, and fast wherrrr type noise, but Idk if that's your clutch fan, or the noise you're concerned about. Or if it's the barely noticeable whine/bearing clatter I hear...

Here's a video I took when mine was doing that.
https://youtu.be/O4UKPnKpGXc

Did you do the belt pull method? Where you take one belt off, run it for a few seconds and listen, take the next belt off, run and listen, then the third belt and listen. If the noise disappears after one of the belt pulls you'll know what exterior component it is. Of noise still persists after all belts are removed, it'll be internal. Most likely the water pump. There is a possibility it could be one of the timing belt pulleys or tensioner. But those tend to last much longer than the water pump bearing. Also a possibility that its the clutch fan bracket. There's an internal bearing on that too. But my moneys on the water pump.

And here's what happens if you let it go too long and it locks up on you while driving. Lol. Not a pretty site. Plus it gushed out all the water in just seconds. And had to be towed.






So again, do the belt pull method right away. Its an easy task. Water pump and timing belt is overwhelming, but I got through it and took me a couple days to finish. There's a few threads around that have good info. Along with writeups, and tips from other members.

 

The more I watch it, it sounds like you're just low on power steering fluid, or its failing. But I can't tell if that's that, or just the engine noise/clutch fan amplified be your cameras mic... I do hear a faint grinding noise like possibly a bad bearing sound, but can't tell. So which is it you're referring to? The crazy loud wherrrr/whine that sounds like power steering? Or the faint rattling ( at least I think I hear that)? You may have more than one issue here..

Because in my vid, all you hear is that HORRIBLE bearing clatter. Ha.

 

Hey, I am refering to the crazy whhhhheeeeeeeeer noise. I just came back from the garage, cost me 20 bucks to know that it is the fan bracket.
So in Quebec it's about 375$ for a reconditionned fan bracket. Dealer is selling it at 1300$... haha. I'll try the graveyard ...

Thank you toendanger you were very useful! I'll try not to end up like you did hehe!

 

The dealer only sells the fan clutch/pulleys/fan bracket as an assembly for tons of money. The OEM Aisin brackets have been available separately in the aftermarket for some time now. Here in the states the "Aisin #FBT104" can be had for just over $100, Rock Auto has it for $107.79.
Stay away from anything not Aisin.

 

There's a thread on here somewhere about replacing just the bearing inside. Can't remember the details. I'll try and find it.

 

There's this too that just developed about greasing the bearing. Might look into that.
https://www.tacomaworld.com/threads/fan-bracket-free-fix-must-read.140451/#post-2793882
But at this point that bearing is running dry and may be causing wear and would only consider this a temp fix. I'd replace the whole assembly anyways. Especially when it's a major component.
Rockauto.com has the bracket for $107
Part #

$120 FBT-004 Fan Pulley Bracket - Compatible with Select Toyota 4Runner, T100, Tacoma, Tundra

FBT-004
For the v6..

Here's a couple writeups suggested to me on the water pump diy. If yiuvdecide to go that route and replace it all.
Post 17.
https://www.tacomaworld.com/threads...agnosed-water-pump-fixed.342053/#post-9176649

And I guess it wasn't a write-up on the bearing. It was just a breakdown pic of the parts and bearing inside. Here:
https://www.tacomaworld.com/threads/fan-clutch-info.412382/#post-11660519

WAS thinking the bearing Could possibly be replaced. Guess not. But yeah, from dealer it's sold as a complete assembly with clutch and everything. Rockauto I think has cheapest price in just the bracket itself. Aisin made...

And you're 100% on it being the bracket right? Used a stethoscope or screwdriver method and listened to th3 bracket? I did this as well and did not here anything on mine so I knew it was the water pump. Its not connected to the water pumo, obviously, so it won't transfer (the sound) to the bracket if it is the pump, in case you we're wondering.

 

At the garage we checked with a stethoscope and the guy was pretty sure about the problem.

So I just finished greasing the bearing of the fan brackett and put everything back together. Started the engine and the sound kept going.

I am suspecting the powersteering pulley now. I have tighten a little bit more the strap and the sound is more intense.

 

Remove that belt, fire up the engine, listen for the sound...

 

I'm in the same boat. Did my t belt and waterpump yesterday. Now I have a metallic scraping sound coming from what sounds like the fan bracket.

When I pulled it off the motor had black steaks with dirt and fuzz stuck to it like it was oil. It started at the bearing and kind of spread out. Sound like the bearing in the bracket puked it's lube out?

 

Yep shoulda done this to begin with. Easiest way to tell if its an exterior component.

 

Just a warning to anyone unsure of where the noise is coming from in this general area...

After completing my timing belt job I heard a loud metal on metal sound. Grinding. I was sure it was the bearing in the fan bracket. Ordered the $100 part and put it in. While removing the belts I noticed the back of the tensioner or idler pulley (below the ac compressor) was shiny metal. Then I remembered one of the parts I had left over was a spacer/washer with a shoulder on it. DING DING DING! Forgot to put it back on.

Moral of the story is I now have a new fan bracket, $100 less, and the feeling of stupidity. This has been my cautionary tale.