Slipping serpentine belt. Broken crank pulley / harmonic damper?

[Eplejus]

Went on a 30 min drive with a couple of 5th gear pulls. When I got back and parked at my garage I started to hear a mechanical clunck noise, almost sounded like heavy rod knock. But the sound was coming from front of the engine. Almost gave me a heart attack. The sound disappeared when shutting off and starting the engine again.

Popped the hood and noticed the serpentine belt was not moving.
I loosend the belt to check all of the pulleys and noticed the inner wheel on the crank pulley was spinning. I guess this is not normal?

Otherwise, the engine runs great. No problems what so ever when revving or driving. Other than getting a error when car is in idle, that the generator won't charge properly.

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[exe36m3]

My guess, and it's a cheap fix, your belt tensioner failed. ($90-ish for the kit) It's basically a spring that pushes the belt tensioner pulley.

Take a look around 2:45.
If your tensioner just swivels by hand, the spring is broken.


Without tension, your belt slips.
And if it slips the alternator won't charge. And if the alternator won't charge, your battery will be dead soon.

 

[Afterburn 549]

If it is under warranty get er done!
I will guess whatever that belt is supposed to be turnining is seized up

 

[Eplejus]

If it is under warranty get er done!
I will guess whatever that belt is supposed to be turnining is seized up

Yeah, I'm calling Toyota tomorrow. Even if the car is tuned, a part like this should just not fail after only 11k miles.
If I can't get it replaced by warranty, I guess I'll just order a ATI Super Damper.

Still is strange, it's like the pulley disintegrated from the rubber on the harmonic damper.
Could be a production fault, or it diden't handle the torque when doing a pull

 

[Eplejus]

My guess, and it's a cheap fix, your belt tensioner failed. ($90-ish for the kit) It's basically a spring that pushes the belt tensioner pulley.

Take a look around 2:45.
If your tensioner just swivels by hand, the spring is broken.


Without tension, your belt slips.
And if it slips the alternator won't charge. And if the alternator won't charge, your battery will be dead soon.

The tensioner is good. What you see on the first video is the pulley have loosened from the harmonic damper. This is what causing the slipping.

 

[Afterburn 549]

That would make more sense, if it was actually slipping there would be smoke !

 

[Twisted Tuning]

crank dampener pulley failure. like you said if under warranty, drop it at the dealer.

 

[lucky phil]

Yeah, I'm calling Toyota tomorrow. Even if the car is tuned, a part like this should just not fail after only 11k miles.
If I can't get it replaced by warranty, I guess I'll just order a ATI Super Damper.

Still is strange, it's like the pulley disintegrated from the rubber on the harmonic damper.
Could be a production fault, or it diden't handle the torque when doing a pull

Or one of the components driven off the serpentine belt has an issue creating high torque on the belt and the balancer coupling is the weakest link.

Phil

 

[i3igpete]

Or one of the components driven off the serpentine belt has an issue creating high torque on the belt and the balancer coupling is the weakest link.

doubtful. localized ring-to-hub torque on a torsional damper is INCREDIBLY violent.

 

[lucky phil]

doubtful. localized ring-to-hub torque on a torsional damper is INCREDIBLY violent.

True, but it's worth checking considering it's failed very early. These things typically last decades not a few years so unless you subscribe to a faulty unit then something else is in play.

Phil

 

[Eplejus]

Talked to my local Toyota dealer today. They could look at it next week.

Anyway, I fired up the car today. Cold engine and components, there was no sign of slipping.
Heated up the engine and it was still good. No noises or anything.
I will take it for a test run later when the weather gets better. Heavy rain outside today.

Just before this happend, I was blasting the AC on full power. That could possibly have caused the problem. Faulty AC clutch maybe? Oh well, the Toyota tech will have to search.

 

[the_wilferine]

This happened to me at around 13.5k miles, replaced it with an ATI Super Damper

 

[exe36m3]

The tensioner is good. What you see on the first video is the pulley have loosened from the harmonic damper. This is what causing the slipping.

Ah, forgive my clear lack of reading comprehension there!
Hope the dealer gets you some resolution!

I did a little research on harmonic dampeners. It's a glued rubber insert/middle piece. So looks like it either tore or the glue failed.

 

[Eplejus]

This happened to me at around 13.5k miles, replaced it with an ATI Super Damper

Interesting. And your is a 2020 as well.
Crank pulley with part number 13740-WAA02 for 2020 models have been discontinued and replaced with 13740-WAA04.

 

[Eplejus]

Update:
So I talked to my Toyota dealer again. They would have to look at the car before they could order any parts. They admitted they have no experience with the GR Supra, and they would also have to order the special tools needed to change the pulley. They expected it would take about 4 weeks.
I offered them to just order me a new crank pulley on warranty and I would fix the problem myself, but of course they wouldn't agree to that.

Soooo, I have ordered a ATI Super Damper from Titan Motorsports and all the tools needed so I can change it myself.
Might as well upgrade and prevent it from ever happening again.

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