What are the odds?

Post by **oragex** » 01 Sep 2018, 05:22

This V70 owner had quite a surprise. He mentioned the alternator clutch pulley was chirping now for a while, he was actually driving to the garage to have it replaced, when, 500m away from the garage, this happened. The pulley broke loose, jumped from there, while the serpentine belt wrapped around the now exposed alternator shaft. I mean, what are the odds the belt would stay there like this?

Worth mentioning that this is a D5 diesel engine (sold elsewhere in the world) which is notorious for bending valves when the serpentine belt fails in one way or another.

Post by **Rattnalle** » 01 Sep 2018, 05:27

I would say that owner had better not take any chances whatsoever ever again. No luck left to spend.

Post by **abscate** » 01 Sep 2018, 08:25

I would play the lottery after that.

Georgeandkira · Post by **Georgeandkira** » 01 Sep 2018, 08:42

Don't play any gambling game of any kind.

As Rattnalle said, his luck reservoir is empty.

Post by **SuperHerman** » 01 Sep 2018, 10:30

Odds are very good. It happens all the times to all sorts of cars. Not unheard of with Volvos, a number of posts can be found where it took out the top end. A friend is working on a 2008 BMW which had a similar issue, the belt literally got sucked into the engine by the rotation. Motor is shot.

Post by **Rattnalle** » 01 Sep 2018, 11:00

SuperHerman wrote: 01 Sep 2018, 10:30 Odds are very good. It happens all the times to all sorts of cars. Not unheard of with Volvos, a number of posts can be found where it took out the top end. A friend is working on a 2008 BMW which had a similar issue, the belt literally got sucked into the engine by the rotation. Motor is shot.

The chance of the engine getting shot is about 99%. But that..

Post by **chrism** » 02 Sep 2018, 10:39

That alt would be spinning about 50,000 RPM!

Post by **jimmy57** » 02 Sep 2018, 11:10

When I pass a car or truck with driveshaft hanging down on ground I always know there are two stories being told. The one where driver says, "all of a sudden the driveshaft fell out" and the one the U joint tells, "I've been squeaking for thousands of miles every time this vehicle takes off from a stop".

BMW 6 cylinders and others with timing chains have serpentine belts get into timing case. I've seen it on BMW more than others and there doesn't seem to be any difference in crank pulley or belt drive to make them look more vulnerable.

The bad part is EPDM rubber lasts so long that it outlives the fiber in belt and makes any visual inspection impossible. It is very much like a tire that gets belt separation and gets squirmy tread or a bubble in tread when the tread has lots of life left.

Post by **cn90** » 02 Sep 2018, 14:29

I wonder the lifespan of a Clutch Pulley (not the solid pulley but pulley with a clutch built in it).
Does anyone know?
I understand that I can buy an INA Clutch Pulley for about $30...but...

Should I replace the whole alternator at ____ miles?

2005 XC90 2.5T 115K

Post by **oragex** » 03 Sep 2018, 01:48

Just my approach, I get a used alt from the junkyard and keep it on the side as long as it still has decent length brushes. It is not easy to give a general lifespan but it is easy to test by hand with the belt off, the clutch should "back spin" without forcing, some friction is still fine imo. I would give it a check at 130k miles. I would expect the brushes to last 150-200k miles.