2G Belt squeal coming from timing belt

[born2race]

Hey all,

2G, 6 bolt block, 7 bolt head. So I recently did my timing belt maybe 200 miles ago. Changed out belt, both pulleys, tensioner & water pump. Tension was set correctly using the loose tensioner pin method & verified proper tensioner arm gap. Recently my timing belt started squeeling on startup. I thought it was an accessory belt, but I took all my accessory belts off and started the car and the squeal was still there. It goes away maybe after 1 min of idling. It’s not a constant noise, almost sounds like a pulley? All replacement parts were OEM Mitsu.

I just installed brand new tensioner, idler pulley and tensioner pulley. Belt is tensioned properly within spec. Started the car after install and did not make noise. After sitting a few days, started the car and it once again started squeeling on startup again.. went away after a few minutes.

Has anybody else experienced this? What could be causing a belt squeal noise from the timing belt system other than the pulleys?

Thanks

 

[Avengethis99]

its too tight

 

[born2race]

its too tight

But how can it be too tight if it’s within the plunger spec on the tensioner?

 

[Dreams Realized]

Is it cold and humid where you live? Sometimes condensation can build up under the belt and cause it to squeak for a short time. If you're within spec like you say I can think of no other cause for this.

And in fact it's not too tight that usually means it needs to be tightened more or cleaned.

 

[born2race]

Is it cold and humid where you live? Sometimes condensation can build up under the belt and cause it to squeak for a short time. If you're within spec like you say I can think of no other cause for this.

And in fact it's not too tight that usually means it needs to be tightened more or cleaned.

It is not, it’s typical humidity and temperature on the east coast. The car is also kept in the garage. I did notice this started happening as it got colder outside. But I’m talking like 30-40 degrees, nothing crazy.

The belt is fairly new and still relatively clean looking. I just would be uncomfortable tightening or loosening the belt if it is within spec as it sits now.

 

[DSMPT]

I took all my accessory belts off and started the car and the squeal was still there.

Are the tensioner/idler pulleys OEM or aftermarket? I have an experience with a cheap aftermarket pulley from a local parts store that scattered all grease at the first startup and started to make a dry bearing noise immediately.
I am not so sure what kind of noise exactly you are talking and around where the noise come from but as you mentioned that the noise is still there without all belts, and assuming the noise come from the timing belt side, most likely tensioner/idler pulleys, oil pump and maybe cam journals. If the cause is a pulley, just replace it.
If the pulleys and the timing belt are not the cause, I would start to be worried about oil pump and cam journals for just in case. if I were you, I would check oil to see if it contain some silver-ish metallic color in oil. and if it does, I would check oil pump and cam journals.

 

[born2race]

Are the tensioner/idler pulleys OEM or aftermarket? I have an experience with a cheap aftermarket pulley from a local parts store that scattered all grease at the first startup and started to make a dry bearing noise immediately.
I am not so sure what kind of noise exactly you are talking and around where the noise come from but as you mentioned that the noise is still there without all belts, and assuming the noise come from the timing belt side, most likely tensioner/idler pulleys, oil pump and maybe cam journals. If the cause is a pulley, just replace it.
If the pulleys and the timing belt are not the cause, I would start to be worried about oil pump and cam journals for just in case. if I were you, I would check oil to see if it contain some silver-ish metallic color in oil. and if it does, I would check oil pump and cam journals.

All pulleys and tensioner were OEM Mitsu both times. Just did an oil change, no metallic/silver flake in the oil.
Yes, the squeal is definitely from the timing belt side. It is the same squel as if your power steering/alternator belt is loose. I have already replaced both pulleys and tensioner with OEM again. So, that leads me to believe that it may be the other items you mentioned. I would just think if those had issues, the symptoms would be much more severe than a belt slipping noise. But I’ll probably start by looking at the cam journals and oil pump since there really isn’t any other culprits. Appreciate the insight!

 

[pauleyman]

Did you check the harmonic balancer? Not sure if it can squeak with the belts not attached . Wouldnt surprise me if its damaged.

 

[Mech Addict]

Now I’m nervous, since I’m having a somewhat similar thing. Did entire timing belt (both), all Mits parts, checked and rechacked/ torqued to speck, and also have had squealing for ~1 minute on start. I was fairly convinced it was p/s,a.c.,alt belts, and tightening those has helped, but not gotten it all to silence. I hadn’t considered that it may be the t-belt or balance belt, but now....
When it’s really cold (0 or below) the motor can also make an altogether different faint ghostly whine, which I kind of guess is an aged rubber seal somewhere (cam?, crank?, other). Not to make this post all about me, but curious about the t-belt noise also now. I didn’t know it was even a thing.

 

[born2race]

Did you check the harmonic balancer? Not sure if it can squeak with the belts not attached . Wouldnt surprise me if its damaged.

I figured it wouldn’t squeak without the load from the belts but yes I checked. It doesn’t have any signs of separation.

 

[born2race]

Now I’m nervous, since I’m having a somewhat similar thing. Did entire timing belt (both), all Mits parts, checked and rechacked/ torqued to speck, and also have had squealing for ~1 minute on start. I was fairly convinced it was p/s,a.c.,alt belts, and tightening those has helped, but not gotten it all to silence. I hadn’t considered that it may be the t-belt or balance belt, but now....
When it’s really cold (0 or below) the motor can also make an altogether different faint ghostly whine, which I kind of guess is an aged rubber seal somewhere (cam?, crank?, other). Not to make this post all about me, but curious about the t-belt noise also now. I didn’t know it was even a thing.

That’s exactly how I thought initially. I thought I just had an accessory belt on too loose as that was the sound it was making. So i just let it be for a bit before trying to diagnose and realized it was coming from inside the timing cover .

 

[DSMPT]

Did you check the back timing covers? Nothing contacts with the timing belt or pulley? Oil pump or cam journals are the worst case scenario, hope it's not

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[born2race]

Did you check the back timing covers? Nothing contacts with the timing belt or pulley? Oil pump or cam journals are the worst case scenario, hope it's not

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That’s an idea I haven’t thought of. I spun the pulleys after I installed to make sure they didn’t bind. And there are no marks on the timing belt or on the inside of the timing cover. But I will def look at the back side when I inevitably have to pull this apart. I feel like if something was making contact though the noise wouldn’t go away after a minute and occur only when it’s cold. Thanks for the ideas! Really hoping it’s not the oil pump or can journals, that’s a scary thought

 

[AWD-Tony]

There’s another bracket for the timing cover on the exhaust side. Can you upload a video? If and when you take it apart again, leave everything off except for timing belt and leave the harmonic balancer and timing cover off, then start the engine and see if noise is still there. Keep in mind you don’t have the water pump belt on when doing this so keep it short.

Also, see if you can slide the grenade pin in without using the tool.

 

[born2race]

There’s another bracket for the timing cover on the exhaust side. Can you upload a video? If and when you take it apart again, leave everything off except for timing belt and leave the harmonic balancer and timing cover off, then start the engine and see if noise is still there. Keep in mind you don’t have the water pump belt on when doing this so keep it short.

Also, see if you can slide the grenade pin in without using the tool.

I will definitely be uploading a video hopefully tomorrow to give everyone a better idea. Grenade pin definitely slides in and out as it should, I just re tensioned the belt and the grenade pin was moving freely and I verified the arm gap distance to spec. Unfortunately it seems like I’ll have to tear everything apart again and run it as you suggested. As a reminder, since this is a 6 bolt block 7 bolt head in a 2g, the tool which compressed the arm manually doesn’t work so the only way to set tension is torquing the tensioner pulley and checking the tensioner arm gap/grenade pin.

 

[AWD-Tony]

The timing cover(s) were pieced together to make it fit? Inspect the inside of the covers as well

 

[born2race]

The timing cover(s) were pieced together to make it fit? Inspect the inside of the covers as well

I actually bought a brand new 1 piece OEM 6 bolt timing cover and trimmed it to fit the 7 bolt motor mount. When I retensioned the timing belt I had to remove the cover and there were no wear/contact marks on the inside of the timing cover. I appreciate all the suggestions though!

Like I said this is more of a loose/wet alternator or power steering belt sound. The sound is only when the motor is cold/car has been sitting for a long period of time & it lasts for a few minutes on initial startup. Once the car is warmed up the sound is gone.

 

[motomattx]

Might be a bearing somewhere making that sound.

 

[Mech Addict]

Would cam bearings or oil pump or other bearings make noise for only ~1 min then go quiet? This would seem to indicate slightly excessive clearance that goes away after some thermal expansion? I’m just trying to think through this scenario. How would this arise after swapping a timing set, if it wasn’t present before?

 

[NorthEasternGSX]

If I were to guess... I would think likely one of those new pulleys is defective. I would take off the timing cover and run it. Maybe that way you can pinpoint exactly where the sound is coming from

 

[born2race]

Hey all, here’s a video of what I am experiencing. This is right after startup.

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[born2race]

Would cam bearings or oil pump or other bearings make noise for only ~1 min then go quiet? This would seem to indicate slightly excessive clearance that goes away after some thermal expansion? I’m just trying to think through this scenario. How would this arise after swapping a timing set, if it wasn’t present before?

These reasons are why I’m thinking it has to be belt/tension related, but I pretty much replaced all those factors other than the belt which is still fairly new.

 

[born2race]

If I were to guess... I would think likely one of those new pulleys is defective. I would take off the timing cover and run it. Maybe that way you can pinpoint exactly where the sound is coming from

Yeah, if I cannot figure it out I think that is what I’m going to have to do. I replaced both new pulleys already, so defective new parts are out of the question.

 

[AWD-Tony]

Almost certain that’s not a belt noise. Belt noise has a higher pitch as you raise the rpms. This sounds like a bearing noise to me.

 

[born2race]

Almost certain that’s not a belt noise. Belt noise has a higher pitch as you raise the rpms. This sounds like a bearing noise to me.

Understood. The only bearings in play other than the pulleys themselves would be the oil pump, correct? Could a bearing stop making noise once the car is warmed up? Even if the car sits for a few hours, it won’t make the noise. It’s only after the car sits for long periods of time. Haven’t confirmed if this time around it is temperature related, but prior it would only also happen during cold weather.