PabloBontt

Good afternoon,
I'm enjoying my first lexus! Also my dream car, silver lexus 460.
I put it to the test stepping on the gas, and the serpentine belt slipped out of the wheel. (no alternator, no AC, no water pump working).
I'm putting a new serpentine now. But just curious why? The car has 143,000 miles. My guess is that it was never replaced. Maybe it stretched some? Maybe the tensioner is not tensioning enough?
Thanks!

CleanSC

If it does it again, you have either a bad tensioner, or another component in the serpentine drive line is loose/wobbly and working the belt off.

Inspect all pulleys, make sure they spin freely and true. If they all check out, and the belt is new, suspect the tensioner.

PabloBontt

Thanks for yout tips!

The alternator is making quite a lot of noise also, I'm wondering if somehow the wheel from the alternator was going a bit heavier than what it should and when I stepped on the gas it contributed to the jump. (The noise from the alternator honestly is quite annoying, I'm thinking about going ahead and replacing it also.

CleanSC

Your alternator may have a one-way pulley on it. These are known to go bad and may toss your belt. Verify it's the pulley (likely) and not the alternator that's bad. If so, you can just change the pulley.

PabloBontt

I found why the serpentine jumped
yep. there you go.

CleanSC

Nice carnage. That'll do it. That idler must have been making quite the racket!

Should run nice and smooth after getting the new one in.

Oliver Enterprises

Pablo - Where in GA are you?

CRowe14

What exactly am I looking at in this photo?

CleanSC

A very chewed up tensioner pulley due to bearing failure. Available separate from the tensioner (provided the tensioner is still good) so it's a cheap fix if you go aftermarket. $10.

If you want OEM, complete tensioner only, about $200.

CRowe14

Thanks so much for that information, greatly appreciate it!

roadfrog

Great post! Thanks.

Tec80

Considering that little bearing lasted 143,000 miles, it did its job. I did a rough calculation and found that it has turned at least 300 million revolutions, all with the same grease from 2007.

CleanSC

Yea, not too shabby. These guys usually warn you so failures like this are pretty rare. They get changed out before they get to this point. OP just bought the car so looks like the PO just ignored it knowing he was going to sell.

CRowe14

A notch for Lexus quality for sure...

Things like this are too bad...but glad the new owner is taking the reigns on fixing the small things to get the car running right again. Take care of a car, it'll take care of you.

Doublebase

I was at a seminar last summer and Gates belt representatives were there and they stressed that belts should be changed every 50,000 miles with the tensioner, which can I found to be ridiculous (and an obvious bias/conflict of interest). But hey, it couldn't hurt. They claim that mysterious check engine lights and loss of power occurs from worn out tensioners and belts...that you can't really visually inspect a belt anymore because they are made from material that doesn't crack like the older belts, instead the rubber just wears away. And the logic behind the tensioner replacement was, because they lose tension they cause the alternator to underpower your electrical accessories...effecting fuel pressure and spark...causing phantom driveability issues. Don't know if I believe that, but that's what I was told.