2008 4.7 Alternator going bad?

[4OYOTER]

I only have 112k, but I suspect my alternator is toast. I just
had my transmission replaced at the dealership for the rumble strip torque convertor issue (covered under a 3rd party warranty I bought with the truck). I literally picked it up this afternoon, drove 10 miles to work with no issues other than I noticed all my radio and trip memory was reset which I assumed was because they disconnected the battery while changing the transmission.

On the 5 mile drive home from work I noticed a whining/groaning noise from the engine bay. I traced it to the alternator. I then tested the battery with a multimeter and the engine running. 12.4 volts. I then tested the alternator directly through the wheel well by removing the gray plastic cover. 12.4 volts also with the engine running.

Im guessing this is completely coincidental from the transmission work, just a bummer they didn't catch it while it was at the dealer. I'm also surpised it seems to be dying at a lower mileage.

I did notice I have what look to be a valve cover gasket leak above the alternator area, but it doesn't look to be bad enough to drip onto the alternator.



Sorry for the dark picture. Thanks for any help. Just want to get another opinion before taking it back to the dealer (alternator is also covered under warranty)

 

[sr3tlaw]

12.4V with engine running is too low. Alternators go bad. I had to replace mine also

Sent from my XT1575 using Tapatalk

 

[4OYOTER]

Just realized the 12.4V was with the headlights and radio on. With them off, I'm getting 13.2V.. Still too low right?

 

[BlackWorksInc]

Just realized the 12.4V was with the headlights and radio on. With them off, I'm getting 13.2V.. Still too low right?

I don't like the voltage under load... I would either have the dealer test it or stop by an autoparts store, they usually have a hand held battery/starter/charging system tester.

 

[SSt4r]

I typically see 13.9ish lights on or off. This too may be a little low but it's consistent.

 

[07V8]

Yep, mine did the same thing.

 

[radlynx]

Here's what i'm getting on a V6 4runner. that's definitely your alternator. I replaced my alternator at around 90000 miles, i'm now at 115000 miles. these are my measurements with my alternator now. My battery is around 4 years old now.

Car has just been turned off: 13.01v
Car voltage after 1 hour and turned off: 12.78v
Car voltage after 12 hours and turned off: 12.69v
Car voltage while turned off and headlights are on including the highbeam and rear glass heater: 11.79v
Car voltage while turned off after the lights test: 12:40v
Car voltage at idle, all lights turned on with AC on high, rear glass heater, high beam and low beam 13.57v.
Car voltage at idle, all accessories are turned off: 13.71v

Just realized the 12.4V was with the headlights and radio on. With them off, I'm getting 13.2V.. Still too low right?

 

[gomoboo]

Increase your RPM to around 2500 with a load, and see if the voltage goes up. Sometimes at idle you won't get full juice.

 

[gshadow325]

i just changed mine a few weeks ago thru the pass fender. 2 hours in and out. but you got a warranty....so off to the dealer if they can cover it.

 

[4OYOTER]

Thanks everyone for the help. I started it up this morning and the whining noise was gone. Brought it to the local auto parts store, they ran a charging / starting test through the battery and said everything was good. A few miles down the road the noise started again. I tested once again when I got home and still 13.2 with all accessories off. It seems to be intermittent so I'll probably wait until it completely dies before bringing it in for warranty service. Just don't want to waste my time if they can't replicate the problem at the dealer. I'm also surprised the battery light hasn't come in the dash, but I'm sure when it gets really bad it will.

 

[blackoutt]

Mine went out around 90k miles on my 07 V8. No indication that anything was wrong then battery light one day. Parked it right there since I was leaving town anyway, when I got back it started and drove 20 miles home no problem. New one went on pretty easy, problem solved.

 

[gshadow325]

Thanks everyone for the help. I started it up this morning and the whining noise was gone. Brought it to the local auto parts store, they ran a charging / starting test through the battery and said everything was good. A few miles down the road the noise started again. I tested once again when I got home and still 13.2 with all accessories off. It seems to be intermittent so I'll probably wait until it completely dies before bringing it in for warranty service. Just don't want to waste my time if they can't replicate the problem at the dealer. I'm also surprised the battery light hasn't come in the dash, but I'm sure when it gets really bad it will.

thats what mine did. its dying, it will leave you stranded one day.

your 4runner will love you as long as you love it back. it wants a new alternator.

fyi in my last 3 years and 40k, mine only wanted a alternator @ 203k. everything else i wanted it.

 

[riceandpho]

change it out before its too late, when you hear the noise, its time, you can get a cheap replacement for the time being if you want to get a high output in the next month or so.

 

[4OYOTER]

Just got it replaced under warranty. I noticed the little silver cover on the power lead is missing.. That should probably be there right?

 

[4OYOTER]

Talked to the shop and they basically said "sorry the new alternator must not have come with one". Anyone know where to get the little plastic cover for the alternator power wire?

 

[BlackWorksInc]

Talked to the shop and they basically said "sorry the new alternator must not have come with one". Anyone know where to get the little plastic cover for the alternator power wire?

Should have been on the alternator wire when they took off the old one... a lot of times it gets broken off or lost (even when you do your best to not lose it/break it).

Apparently this is the part number for it: 82823-22050

 

[gshadow325]

Apparently they lost it or dropped it and now is swept up into the trash, at least that's where mine went when I changed it lol. I found it a few days after I finishedd it and it back

 

[ran]

Wasn't there a thread back about using a high output Supra Alternator that was plug and play?
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2007 SE V6