ULTiMaX99

iTrader: (5)

has anyone replaced their alternator before? how hard is it to replace in an is250? got any tips or diagrams?
i had a squeak around the serpentine belt area and the dealer diagnosed the sound coming from the alternator. my guess is that it's a bad bearing. they want $1,064 to replace the alternator. i really don't want to shell out that much money so i'm gonna see if i can attempt this on my own first.

Gville350

iTrader: (10)

Have you had your water pump replaced before? It is more likely the pump failing...I have yet to read about an alternator failure. The bearing in the pump typically goes and soon you will probably find your motor running hotter than normal at times. Good thing about the water pump replacement though is that it is covered under the factory powertrain warranty!

GL!

ULTiMaX99

iTrader: (5)

i haven't had the water pump replaced yet, but i've read about some people having to replace theirs. the dealer said they unplugged or disconnected the alternator and the squeal went away, so they're confidant its the alternator.

dackp143

iTrader: (3)

Should be the same as any other vehicle. Take off the belt, loosen the bolts, unplug the few wires attached to it, and then finally remove the bolts completely and put in the new one. Hardest part will be reaching the alternator but its obviously possible. If I were you, I would take photos of where everything is plugged into so when you put the new one in, you know where everything is thing is plugged into. Easy day. While you have the serpentine belt off though, you might as well replace it with a new one since they are so cheap.

F*** $1k for a new one, buy one yourself and install it. You will learn a few things as you go.
$414 on Sewell Lexus: http://is.sewellparts.com/oem-catalo...S250-2006.html

ULTiMaX99

iTrader: (5)

i've looked at some tutorials and some youtube videos and it seems easy enough, but just wanted to make sure there are no tricks or tips i should be aware of. the location of the alternator looks like it's in a pretty accessible area too. i also plan on replacing the serpentine belt since i'll have it off. i also plan on getting it from sewell... the dealer wants 617 just for the alternator. the rest is labor and diagnosis charge.

Gville350

iTrader: (10)

While in there, you might as well do the water pump too.

BTW, unless they physically removed the drive belt from the alt. pulley and everything else and started the car...how would they know if that sounded the sound? Just simply disconnecting cables to the alt. only disconnects power coming/going to it...the pulley keeps spinning regardless if the belt is still attached. Sounds like they "think" they know what it is.

LEXtegra

Hey ULTiMaX99, what type of squeaak do u have? I just got a squeak 2 days ago. I'm almost 100% sure its not the belt. It starts when the car is at an idle but it doesn't really start squeaking until I put it in drive or reverse. I'm gonna take the belt off tomorrow and see where its coming from. How many miles do you have on your IS? I'm currently at 72,000 so I guess it is time for a water pump. I hope thats where the noise is and not somewhere else.

LDNN

Get a second opinion from an independent shop first then decide if it's worth your time and hassle to DIY.

JohnLX300

iTrader: (2)

Get a mechanics stethoscope.....find out for yourself, at least you can trust yourself! I got one for my older car because I was told alternator at the dealership....and it was a timing bearing...go figure!

wcarty

I had mine done about 6 months ago and the dealer charged me 1500. Mine shorted out while driving.

calvin2376

iTrader: (2)

So your alternator is squeaking? Is that all it's doing? It's not actually failed? Because a failed alternator would cause clear symptoms. The alternator went out on my LS400 while I was driving and the whole car's power cut out on the highway, as the alternator had failed and the battery's power was depleted.

I'd just never heard of an alternator squeaking before.

ULTiMaX99

iTrader: (5)

the water pump looks pretty intimidating to replace. not sure if that's something i can diy? plus i'm still under the powertrain warranty and if it was the waterpump, i would have the dealer replace it for free. i'm not exactly sure how they diagnosed the alternator, but i did pay them $73 to diagnose it. does anyone know what recourse i have if it turns out that they misdiagnosed it and it's not the alternator?


the squeak is very high pitched, like a chirp. i get it when i first start it up and when i accelerate slowly in 1st gear (i have a manual). i also get the squeak when i'm in a higher gear than i should be (going 20 mph in 4th gear, with rpms under 1,000). i don't get it when idling in neutral, however, if i turn on my ac, i get a continuous chirp every 1.5 seconds or so. it seems as though i get the noise when there is some strain on the engine. i have almost 65,000 miles.

ULTiMaX99

iTrader: (5)

according to the dealership, the source of the squeak is the alternator. it's not failing. i've seen alternators where the bearing inside is causing the squeak.

Jay hall

Heya ULTiMax99 ... i understand exactly what you are talking about dude. my car too has that squeaky sound.. it sounds like the belt but it isn't. When i took to the dealers they too said its the alternator. But the thing that i have noticed abt the squeaking is, it only happens on cold start or when i first start it in the morning. Once my car is warm enough the sound goes away. Then again the squeals do come more often even if it isn't a cold start when my car is almost due for its service. I have my car serviced every 5000 Kms. After the service its quiet for the next 2000 or 3000 kms. i haven't replaced my alternator bcoz its really expensive but i get really annoyed when it does squeal..makes me think my car is a old Tercel ..lol..

prankster

iTrader: (3)

I have exactly the same issue (manual trans. too). I removed the belt and rotated each pulley with my hand (engine off of course). Found out that the chirp came from the alternator bearing. Better replace it ASAP before you are stranded.

Go find out before you buy parts. It takes 15 minutes total to remove and install the belt.

I just purchased an alternator from autozone. $178 after you return the core. Replacing an alternator is very easy. I can write up a DIY guide if time allows. My car is at 65000 btw.