Timing Belt Whine

[zachary.mikel]

Hey guys, I'm hoping that someone can shed some light on something going on with my 4Runner. The truck is a 1997 SR5 with 221k miles on the clock. I figured I would do some preventative maintenance and get in to do the timing belt, water pump, tensioner, pulleys, and crank seal (there was a significant amount of oil coming out around that area.)

I ended up doing the job twice - I cheaped out the first time and got a timing belt kit from RockAuto with a non-OEM water pump. Big mistake, the pump came with metal burrs on the mounting surface and didn't mate to the block properly. A coolant leak appeared within a couple of days, so I pulled it back apart and did all oem stuff - another new gates belt, Toyota tensioner, water pump, pulleys.

When the truck is idling, I can hear a whining/droning noise that wasn't there before. I took the truck apart again last night to make sure that I didn't put the crankshaft washer/timing belt guide on backwards, and sure enough the rounded edge is against the timing belt.

TL;DR, I have done the timing belt job twice now and both times I've heard a whining/droning noise that didn't seem to be there before I replaced the belt. The noise can be heard in the video below, about the same frequency range you'd expect to hear a supercharger. The picture shows where the noise is coming from with a stethoscope.

It's also very possible that this is a normal sound and I just haven't noticed it before. Thanks for the input!

 

[thegipper]

Did you maybe forget to put the washer behind the tensioner pulley bracket? It looks like the tensioner pulley is sitting too far reward towards the engine as if the washer is not there. Part of the belt is hanging off that pulley.

I just did a timing belt job on my 97 last week so this is all fresh in my memory.

 

[zachary.mikel]

Did you maybe forget to put the washer behind the tensioner pulley bracket? It looks like the tensioner pulley is sitting too far reward towards the engine as if the washer is not there. Part of the belt is hanging off that pulley.

I just did a timing belt job on my 97 last week so this is all fresh in my memory.

It's very possible, I thought it was odd how far forward the belt looks like it's sitting. Remember how thick the washer was by any chance? It seems like it would need to be fairly substantial since the belt is sitting a good 1/8" off the pulley.

 

[thegipper]

I don't have an exact measurement but its definitely a thick washer.

I actually lost mine when I was tearing it apart. My dealership couldn't get me a new washer for a few days so I found a different thick washer and used that instead. Seems to have worked fine.

If I had to guess, I'd say 2.5 - 3mm thick.

Check and see if that washer is there or not. My belt was not hanging off the tensioner pulley like that.

 

[zachary.mikel]

I don't have an exact measurement but its definitely a thick washer.

I actually lost mine when I was tearing it apart. My dealership couldn't get me a new washer for a few days so I found a different thick washer and used that instead. Seems to have worked fine.

If I had to guess, I'd say 2.5 - 3mm thick.

Check and see if that washer is there or not. My belt was not hanging off the tensioner pulley like that.

Will do. I'll report back here when I get some time to tear into it again. I bet your timing belt doesn't sound like that either ! :lmao:

 

[thegipper]

Correct, I do not have that whine.

You should be able to see if that washer is there or not by just removing the top plastic timing belt cover and using a mirror/flashlight to see if that washer is there or not.

let us know what you find.

 

[TheDurk]

TOYOTA P/N 90201-10098

 

[zachary.mikel]

TOYOTA P/N 90201-10098

You're a life saver. Thank you sir. I'm going to order one now and tear back into it this weekend.

 

[zachary.mikel]

let us know what you find.

Life got away from me a bit, so I wasn't able to get back to the timing belt troubleshooting until this weekend. I'm about at the end of my rope with this whining noise.

I went in and pulled the tensioner off, and sure enough the washer was not on the back! I ordered a new one from the dealer and reinstalled. I followed a couple of online guides in reassembly, torque specs and all. I'm getting pretty quick at this...

The noise is still there! I'm not sure what else to check at this point. It is 100% timing belt related, I made sure to fire it up with the accessory belts totally off and the noise is still present. Any other ideas?

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[thegipper]

How is your fan bracket? Is it smooth and quiet?

Maybe you got a bad tensioner pulley or something?

 

[mtbtim]

I think Mike is on the right track. Pull the timing belt off and manually inspect both idler pulleys, the water pump pulley and the fan bracket bearing. The noise is most likely coming from one of those.

 

[zachary.mikel]

How is your fan bracket? Is it smooth and quiet?

Maybe you got a bad tensioner pulley or something?

I have replaced the tensioner pulley and the idler pulley... (the tensioner pulley twice.) I haven't paid much attention to the fan bracket. Once I get more time I'll pull everything off and inspect with my stethoscope. I was so sure that the washer was the problem that I put everything on yesterday, not stopping to listen to just the t-belt.

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[zachary.mikel]

I think Mike is on the right track. Pull the timing belt off and manually inspect both idler pulleys, the water pump pulley and the fan bracket bearing. The noise is most likely coming from one of those.

The water pump is a brand new Aisin pump, so I'm thinking fan bracket.

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[thegipper]

Yeah its probably the fan bracket then.

Keep us posted

 

[spartacus]

Check the the timing belt guideplate on the crankshaft under the lower Timing belt cover. This guideplate is dish shaped and goes on one way. If it is put on backwards it will dig into the belt and cause a whine. good luck

 

[thegipper]

Check the the timing belt guideplate on the crankshaft under the lower Timing belt cover. This guideplate is dish shaped and goes on one way. If it is put on backwards it will dig into the belt and cause a whine. good luck

That's a great suggestion. The convex'd end goes towards the belt and the concave'd end goes towards the crank pulley. Make sure it is on correctly.

 

[zachary.mikel]

Check the the timing belt guideplate on the crankshaft under the lower Timing belt cover. This guideplate is dish shaped and goes on one way. If it is put on backwards it will dig into the belt and cause a whine. good luck

That's a great suggestion. The convex'd end goes towards the belt and the concave'd end goes towards the crank pulley. Make sure it is on correctly.

That is a really good point. When I took it apart the first time, I made sure that it was installed facing the correct way. I read in an older thread about this, and that was my first thought.

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[zachary.mikel]

Update: it was a bad idler pulley. I installed a new KOYO pulley when I first did the timing belt. Just swapped it out for an OEM replacement and the noise has vanished. Thank you guys for your help! Onto suspension work!

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