Accessory Belt Tensioner - Pulley or Assembly?

Post by **vtl** » 25 Jan 2023, 06:59

I broke like 3 INA tensioners in recent years. The casting is very weak. I made sure torx bit is long and engages at all the depth, but it still broke off. The one for B5254T12 engine was especially weak. Resorted to moving new pulleys to old tensioners.

Post by **cn90** » 25 Jan 2023, 10:50

How is the new INA (unless counterfeit) broken?
Is it broken at the bolt?
What is exactly broken, during installation or weeks later?

Post by **vtl** » 25 Jan 2023, 11:00

cn90 wrote: ↑25 Jan 2023, 10:50 How is the new INA (unless counterfeit) broken?
Is it broken at the bolt?
What is exactly broken, during installation or weeks later?

Thin casting wall broke off where the torx hole is.

Post by **erikv11** » 26 Jan 2023, 12:24

cn90 wrote: ↑25 Jan 2023, 05:58 Mileage is a very useful indicator in car repair.

Of course everyone drives differently...city, city-hwy mix, vs mostly highway. But to me, mileage is a very useful indicator.

In a perfect world, you measure number of revolutions (# cycles) and figure out how many millions revolutions before changing belt.

In the absence of that data, most owners manual use odometer reading, which is more practical.

Mileage is useful agreed, but as a guide for checking not for reflexive replacement. Hours of usage would be a far better indicator if we could get it!

My point regarding using mileage as a basis is to be wary of posts in the fora saying "this part fails at xxx k." There are very few parts that fail on a narrow mileage window. So most posts like that will, for example, mislead people who are new to the game or trying to figure out where to spend their maintenance budget.

Post by **jonesg** » 26 Jan 2023, 13:50

vtl wrote: ↑25 Jan 2023, 11:00
cn90 wrote: ↑25 Jan 2023, 10:50 How is the new INA (unless counterfeit) broken?
Is it broken at the bolt?
What is exactly broken, during installation or weeks later?
Thin casting wall broke off where the torx hole is.

that might be due to it being injection molded with sintered metal, I see it on many kitchen machine parts "not safe for dishwasher."
The high temps form cracks. Had it happen on a big commercial mixer paddle, the break revealed tiny bubbles in the metal.
I wasn't able to weld it, $400 down the drain.

a3inverter · Post by **a3inverter** » 26 Jan 2023, 16:00

My PS pulley is 5 1/8", so I'll get the shorter belt. Thanks all!

Post by **cn90** » 27 Jan 2023, 07:39

Over the yrs, I have installed many INA tensioners w/o issues in BMWs and Volvos. Last time I installed the INA was 1 yr ago.

Does anyone know when this INA issue came up, is it recently?

Post by **vtl** » 27 Jan 2023, 08:25

cn90 wrote: ↑27 Jan 2023, 07:39 Over the yrs, I have installed many INA tensioners w/o issues in BMWs and Volvos. Last time I installed the INA was 1 yr ago.

Does anyone know when this INA issue came up, is it recently?

Installed one in 2013, it was good, like the factory one.

In 2017 it was already a new flimsy design.

P3 INA tensioner I got in 2019 was bad, too. Factory one in MY2016 car was ok. Well, besides made in India bearing that failed in 3 years.

Post by **erikv11** » 27 Jan 2023, 12:20

P2 INA tensioners installed due to pulley bearings getting dry:

S60 in July of 2020, 168k
XC70 in January of 2021, 172k

Source was FCP for both. Can't comment on flimsy or not, I did not notice anything. They are still working so far.

Post by **cn90** » 27 Jan 2023, 20:02

@vtl,

Did yours break at the Torx hole (for tensioning the belt during installation) as shown in
this thread below on 2015 S60 5cyl:

https://www.swedespeed.com/threads/2015 ... es.656912/

Accessory Belt Tensioner - Pulley or Assembly?

Re: Accessory Belt Tensioner - Pulley or Assembly?