When Will My Alternator Die?

[Ravenwoods]

Our 1998 Forester has 191,000 miles on it and we got it when it has 103,000. It seems that it is due for an alternator failure any time. My GMC truck, with 143,000 miles, had its alternator die yesterday with -30 F. weather. But fortunately I've got a heated garage, so got it changed easily. Just getting it home was the struggle.

 

I had a Nissan Stanza once and it seemed its alternator gave up sometime after 170,000 miles.

 

Just wondering what alternator experiences other's have had. I'm just trying to guess the most likely problems to turn up next. My guess is the starter motor and the alternator are the most likely things. I've already replaced plugs, wires, injectors, timing belt, timing belt tensioner, clutch, lots of pulleys.

[coolskaterkid]

on my 92 legacy it died around 180k, im sure others get a lot more then that though just depends.

[porcupine73]

My '00obw alternator died, well actually got super excited and was putting out 16 volts, at around 110,000 miles.

 

My '96 I have no idea because it already had a napa starter in it when I got it, but those years had problems with the brushes and a recall.

 

My '94 I haven't looked to see if it has the original in it or not.

 

Since we're taking odds, I'd give yours another 3 years / 30,000 miles. Just kidding, I mean it is of course impossible to know, and even a brand new genuine one could have a defect leading to failure in a short period of time.

 

Don't forget sensors / electrical parts. Engine coolant temp sensor (although that can be considered low priority because the engine will still run without it), cam angle sensor, sometimes crank angle sensor, knock sensor (not mission critical though). I also notice you didn't list water pump; those usually last a good long time though. How about your radiator and heater hoses?

[Ravenwoods]

My '00obw alternator died, well actually got super excited and was putting out 16 volts, at around 110,000 miles.

 

My '96 I have no idea because it already had a napa starter in it when I got it, but those years had problems with the brushes and a recall.

 

My '94 I haven't looked to see if it has the original in it or not.

 

Since we're taking odds, I'd give yours another 3 years / 30,000 miles. Just kidding, I mean it is of course impossible to know, and even a brand new genuine one could have a defect leading to failure in a short period of time.

 

Don't forget sensors / electrical parts. Engine coolant temp sensor (although that can be considered low priority because the engine will still run without it), cam angle sensor, sometimes crank angle sensor, knock sensor (not mission critical though). I also notice you didn't list water pump; those usually last a good long time though. How about your radiator and heater hoses?

 

I forgot to mention I just replaced the upwind oxygen sensor. Also the cat was replaced maybe 40,000 miles ago.

 

I did replace the knock sensor also--maybe 40,000 miles ago. I forgot about the water pump. Hope it holds out for much longer.

 

Radiator and hoses look good to me. Up here in Fairbanks, Alaska they don't use much salt on the roads as it is not effective in our extremely cold temperatures. So as far as external corrosion to the radiator, there isn't any. We have short summers so hot weather doesn't have much effect on the rubber parts. In the winter our car is in a heated garage--but that has only been for the past few winters. That cuts down on wear and tear on the car a lot. We've replaced the radiator fluid a few years ago.

[jp98]

Do you have a quarter to toss into the air and take a guess? It may last another 50,000 miles and then again it may crap out on you tonight. Then how is your luck on the one that you get from a parts store? Most all alternators that you buy are going to be rebuilt and they are only as good as the rebuilder.

 

When I had to replace my alternator on my Outback I picked up one from NAPA with a lifetime waranty. It lasted over night. The next one that I got from them was the same as the first. Now I am still running the third one after 50,000 miles.

 

At times you just never know.

[Fairtax4me]

Yeah there's no telling when it might fail. What you do is go to the Subaru dealer and order one for a 95 Legacy. $75 and it drops right in. $50 core but you'll get that back.

[J A Blazer]

2000 OBW, currently with 155K. Alternator went out at about 135K. Starter more recently.

[idosubaru]

like they said, you never know. i've been thinking the same thing on our 182,000 mile 2002 OBW with the original alt. i have a brand new Subaru unit waiting for it. since i have two identical H6's i'll probably install the new one in one and resort to #1 suggestion below with the original for the other vehicle.

 

if you're anal about reliability (i try hard to avoid break downs) i have two suggestions:

 

1. get a known good used one and put it in the spare tire compartment with the 2 or 3 wrenches needed to change it. they are so easy to change on a subaru that it's not that big of a deal to replace. literally 15 minutes. i used to do that in college and while i never actually had to do it - it was cheap piece of mind.

 

the first brand new alternator i bought i kept it in the trunk until the original died - i forget how many miles it made it too. my wife was with me rolled her eyes when i said "15 minutes" and was laughing when it only took me 10!

 

2. if you plan on owning the car a long time, then buy a new one now or have yours professionally rebuilt. if you're going to own the car to 250,000 miles, then why wait until 220,000 for it to fail and buy another you'll only get 30,000 miles out of? just get one now...now if you're plannning on 400,000 miles then maybe maxing this out is more justified.

 

i wouldn't think that over the long term an aftermarket unit is all that reliable - compared to new Subaru units anyway. who knows, but i've seen tons of aftermarket alt's fail. i'd feel better with a $35 used one in the trunk than an aftermarket any day of the week - SPF's (Single Points of Failures) are bad news to engineers - and you are correct in the thinking the alt is likely to be the main culprit at letting you sit....though they often do give "signs" first. noise, heat, voltage fluctuations, or glowing dash lights.

[987687]

pretty close to where I lived in Maine there was a guy who'd rebuild starters for $40 + expensive parts.

My 96 lost its brushes at 115k miles or something. For $45 I had him put in new bearings, brushes, clean it all up and stress test the diodes and regulator.

I kept that when I sold the car... So look for the old timers who do this stuff, they do good work, talk your ear off, and keep your car on the road.

 

About your starter, the most common reason they fail is bad contacts. Take it apart and replace the contacts. Even tear the whole thing down, inspect it for wear and re-grease it. It's really easy!

[bratman18]

pretty close to where I lived in Maine there was a guy who'd rebuild starters for $40 + expensive parts.

My 96 lost its brushes at 115k miles or something. For $45 I had him put in new bearings, brushes, clean it all up and stress test the diodes and regulator.

I kept that when I sold the car... So look for the old timers who do this stuff, they do good work, talk your ear off, and keep your car on the road.

 

About your starter, the most common reason they fail is bad contacts. Take it apart and replace the contacts. Even tear the whole thing down, inspect it for wear and re-grease it. It's really easy!

 

Same guy did mine. It was an even 40 bucks for him to completely rebuild it. That price includes the parts. A lot better than the 300 I was quoted for a remanufactured one

[987687]

Maybe it was an even $40 for mine too. I can't remember, but it was a damn good deal. He's a cool old timer to talk to, hah a lot of good stories.

[john40iowa]

My 'Forester is on its original Alternator, fuel pump and starter. I am pretty happy about that! I do change my battery religiously about every 5 years regardless of performance. It probably doesn't make a lot of difference but I turn everything (accessories) off before I start the car, I plug it's block heater in both at home and work; keep the entire enigine itself very clean. It is approaching 200K, mostly in town miles.

[The Dude]

My 99 Forester had the orignal altenator, starter, ac, ps pump, fuel pump, fuel injectors, engine (no repairs), AT (no repairs) and steering rack when I sold it at 200,000 miles. Man, I loved that car. I probably sold it 1000,000 miles too soon.

[Ravenwoods]

Our -30 F. weather has moderated a bit to -15 or -20. But this morning when I started up the Forester, I immediately heard a new noise. Later as I stood in front of the car and listened, I thought, "That is probably the alternator bearings starting to go in this cold."

[LoveTheeSubie]

I used to have a 92 Legacy L. My alt. craped out on me at 199,050 K on Christmas Eve a few years ago in the dead of winter. I started it up a few days later and drove it to the parts store and bought a new one! Then I sold it when the Tranny started to slip at 250K. Best Investment ever!!!!

[lewisd]

At 256,000 miles my 99 brighton wagon still has it's original alternator and most other major compponents. watch it all crap out on my now....

[idosubaru]

this morning when I started up the Forester, I immediately heard a new noise. Later as I stood in front of the car and listened, I thought, "That is probably the alternator bearings starting to go in this cold."

the accessory belt idler pulley bearing is a more common failure item, check that first to be sure.

 

Same guy did mine. It was an even 40 bucks for him to completely rebuild it. That price includes the parts. A lot better than the 300 I was quoted for a remanufactured one

i did the same thing but that alternator eventually failed - for that price they are probably not replacing the voltage regulator which is typically an expensive part and probably has failure modes to it as well.

[john40iowa]

the accessory belt idler pulley bearing is a more common failure item, check that first to be sure.

 

Where exactly is that that pulley and how hard is it to replace?

[bheinen74]

i did the same thing but that alternator eventually failed - for that price they are probably not replacing the voltage regulator which is typically an expensive part and probably has failure modes to it as well.

 

typically, a "rebuilt" alternator has only:

1. new bearings

2. New Brushes

3. new windings.

 

 

 

That is it.

 

I have seen alot of rebuilt alternators fail shortly after purchase from autostore, sometimes fail instantly. I believe it is because they do not replace the voltage regulators.

 

The VR are delicate, and a newly winded alternator is going to put out some high current when it is new, and the already old delicate VR dies instantly.

 

Then you have a whole mess of problems, of overcharging, cooking the battery, etc.

 

I do know I would rather get a oem junkyard alternator and take the chance on it, then going to the parts store and getting one with a nice new "rebuilt" sticker on it.

 

Someone who is close to a autostore please ask them what the rebuilt alternator means. Ask them if the VR is new too.

 

You know what the answer will be? Well, it is warrantied, so if you have a problem we will exchange it. So then ask them how many alternators they have to take back on warranty. You will be shocked of the answer.

 

Warranty on a alternator is a big hassle to me. I don't live close to the autostores, etc. I can go buy 2,3, or 4 at the junkyards and take my chance on them working and it costs less. But if i see the "rebuilt" sticker on them I have purchased a few and learned not to do that anymore, they are the junkones. The oem are good, but anything i have got with the rebuilt sticker is bad.

Edited November 20, 2011 by bheinen74

[hohieu]

Where exactly is that that pulley and how hard is it to replace?

 

It's part of the tensioner assembly for the AC belt on the left (driver's) side of the engine and is very easy to replace.

 

I just opened my alternator up at 170K miles and all the wear items still looked fine. Brushes still had plenty of life left on them and the bearings were still smooth and tight. Don't over tighten the accessory belts, and the bearings (and belts) will last a long time.

Edited November 20, 2011 by hohieu
clarity

[987687]

The reason people say to replace that is because the bearings like to fail, they start getting a little sideways, eat a hole in the timing cover, and in worst case ruin the belt.

 

I had one start chewing a hole in my timing cover, but fortunately I came to a stop light and wondered WTF is that terrible noise... It had taken a pretty good chunk out... I took out my knife in traffic and cut the belt..

[john40iowa]

It's part of the tensioner assembly for the AC belt on the left (driver's) side of the engine and is very easy to replace.

 

I just opened my alternator up at 170K miles and all the wear items still looked fine. Brushes still had plenty of life left on them and the bearings were still smooth and tight. Don't over tighten the accessory belts, and the bearings (and belts) will last a long time.

 

Thanks. Sorry to ask a dumb question, but what is procedure for changing the belts on the 2.5 SOHC. I have done belts but never on Subie.

[nipper]

Our 1998 Forester has 191,000 miles on it and we got it when it has 103,000. It seems that it is due for an alternator failure any time. My GMC truck, with 143,000 miles, had its alternator die yesterday with -30 F. weather. But fortunately I've got a heated garage, so got it changed easily. Just getting it home was the struggle.

 

I had a Nissan Stanza once and it seemed its alternator gave up sometime after 170,000 miles.

 

Just wondering what alternator experiences other's have had. I'm just trying to guess the most likely problems to turn up next. My guess is the starter motor and the alternator are the most likely things. I've already replaced plugs, wires, injectors, timing belt, timing belt tensioner, clutch, lots of pulleys.

 

 

The starter motors on these things don't usually go bad, it is the solenoid contacts which are easy to replace.

 

An Alt is NOT a cheap thing to replace the parts on and rebuild. After having bought rebuilds (one from subaru no less) I have started going the used route.

 

When will it go? When you have a women in labor in the middle of a showstorm while the dog is getting car sick 50 miles from anywhere.

 

If you are worried about it get a voltage gauge. They will usually start to drop voltage (that you can't see normally) as they start to go. Of course some of them just go poof. If you really are worried about it get a replacement and either store it or go ahead and replace yours.