Rattle sound from alternator

[mk_v]

Hi all! I'm having a odd problem with my jeep. Seems to be a internal rattle inside the alternator. It isn't constant but intermittent. I noticed it yesterday when I was warming it up. There isn't a drop off in power going to the battery, and I replaced the tensioner, about 2000 miles ago. The belt is a mopar belt replaced about 15000 miles ago. Also when I turn off the jeep there is a squeak from the belt. To me sounds like from the alternator pulley. Is this a sign the alternator is going out? Should I replace the whole unit? The jeep has 80,000 miles. Also when the rattle inside the alternator does happen I can feel it when putting my hand on the outside of the alternator. I took off the alternator and the pulley turns and spins freely.

Thanks!


Mk

 

[M38 Bob]

99% of the time that sort of issue will get progressively worse long before leaving you stranded. Unless you plan a long distance trip in the near future, I'd suggest waiting for a bit, let it get bad enough to diagnose without guessing.

Other option would be just replace it with a lifetime warranty reman and be done.

Bob

 

[Birdman330]

I'd take option number two, makes it faster easier and better piece of mind. Since I'm the person that goes crazy when a new noise is present.

 

[mk_v]

99% of the time that sort of issue will get progressively worse long before leaving you stranded. Unless you plan a long distance trip in the near future, I'd suggest waiting for a bit, let it get bad enough to diagnose without guessing.

Other option would be just replace it with a lifetime warranty reman and be done.

Bob

I may be dense but where do you get a lifetime warranty for a alternator? I called the jeep dealer they want 259 and the alternator that is installed that I think is going bad. Or they charge 100$ core charge. Should I look elsewhere? It's a renegade so I know the alternator is bigger than the sport models.
I drive it on the back roads for hunting this season so I'd rather not get stranded if you think that it may be getting bad.
Thanks for the replies!


Mk

 

[LibertyTC]

With rattles, I would prefer to use an auto stethoscope to better pinpoint noise locations.
You could remove the belt, and check for play and ensure a smooth turning pulley on the Alt.
OEM Alt's last a very long time. That is the route that I would go, if replacing it.

 

[mk_v]

With rattles, I would prefer to use an auto stethoscope to better pinpoint noise locations.
You could remove the belt, and check for play and ensure a smooth turning pulley on the Alt.
OEM Alt's last a very long time. That is the route that I would go, if replacing it.

I tried to get one today but Napa and autozone didn't have any. I did take the alternator off and the pulley is moving freely when I turn it
And I feel pretty confident thinking it's the alternator rattling because when it's running I can feel it when I put my had on the outside of the casing where the band is. Is the alternator supposed to be fairly hot? Not to hot to touch but close to it.


Thanks

Mk

 

[ltd02]

I may be dense but where do you get a lifetime warranty for a alternator?

I'd like to know this too. I've replaced two within the past year (different vehicles) and never saw a lifetime warranty from anyplace. :shrug:

 

[ltd02]

And I feel pretty confident thinking it's the alternator rattling because when it's running I can feel it when I put my had on the outside of the casing where the band is. Is the alternator supposed to be fairly hot? Not to hot to touch but close to it.

Not for my KJ, but I'm hunting for one right now too for the exact same reason. I'm hearing a sporadic knock that also sounds and feels like the alternator. I had my hand on it after running it for quite a while and unlike yours it was not hot at all. The knocking on mine seems to stop after 5-10 minutes. I'm looking to replace it and keep the current one as an emergency spare. The OEM I'm looking at is a Hitachi and can be had on Amazon.

Did you try Amazon and/or Rock Auto?

 

[mk_v]

Not for my KJ, but I'm hunting for one right now too for the exact same reason. I'm hearing a sporadic knock that also sounds and feels like the alternator. I had my hand on it after running it for quite a while and unlike yours it was not hot at all. The knocking on mine seems to stop after 5-10 minutes. I'm looking to replace it and keep the current one as an emergency spare. The OEM I'm looking at is a Hitachi and can be had on Amazon.



Did you try Amazon and/or Rock Auto?

My sound seems to go down a little after warmed up but still rattles about every 5-20 seconds. And it's squeals when I shut it off. Which I know is a new symptom from this weekend. The clicking I may not have noticed if it was there but couldn't have been more than a couple weeks. I'm thinking just replace it and see if it helps at all with the squeal and rattle. The one on my jeep is a denso, is yours a hitachi?


Mk

 

[ltd02]

My sound seems to go down a little after warmed up but still rattles about every 5-20 seconds. And it's squeals when I shut it off. Which I know is a new symptom from this weekend. The clicking I may not have noticed if it was there but couldn't have been more than a couple weeks. I'm thinking just replace it and see if it helps at all with the squeal and rattle. The one on my jeep is a denso, is yours a hitachi?

No I replaced the KJ a few years ago with a rebuilt Denso (dealer had one at a decent price). I'm having the knocking problem on my daughter's Subaru. Pretty sure its the same issue since it "rattles" sporadically like your. Just want to be prepared for when it finally does quit. My Alternator experiences have been like Bob mentioned before, slowly getting worse and not catastrophic failures.

Looks like they have your 160A version here but pricy:

Denso 210-0484 Remanufactured Alternator

 

[M38 Bob]

OReilly "Ultima" part # 13913 160amp with lifetime warranty. List is 203.37, as a walk in customer you can expect to pay around $150.

Bob

 

[M38 Bob]

Actually lists at my local store as $119.95 with core. Core price is $32.

Not in stock, but in district warehouse, so it'd be in the next day.

Bob

 

[ltd02]

OReilly "Ultima" part # 13913 160amp with lifetime warranty. List is 203.37, as a walk in customer you can expect to pay around $150.

Bob

Bummer, no O'Reilly's around me. Just noticed Rock auto has the 160A rebuilt Denso if the OP can wait for delivery.

 

[LibertyTC]

I tried to get one today but Napa and autozone didn't have any. I did take the alternator off and the pulley is moving freely when I turn it
And I feel pretty confident thinking it's the alternator rattling because when it's running I can feel it when I put my had on the outside of the casing where the band is. Is the alternator supposed to be fairly hot? Not to hot to touch but close to it.
Thanks
Mk

Did you have any in/outwards movement on the pulley at all, or was it tighter than a drum?
Rattling when running, bearing or could have some sort of internal loose part in there?
If you are only running the Alt with hood open for 10 minutes, it is not going to get super hot.
Close the hood though,and include engine head heat, and the 160 amp alt running at hwy speed= don't touch it for a while. :flamingdevil:

 

[mk_v]

Did you have any in/outwards movement on the pulley at all, or was it tighter than a drum?
Rattling when running, bearing or could have some sort of internal loose part in there?
If you are only running the Alt with hood open for 10 minutes, it is not going to get super hot.
Close the hood though,and include engine head heat, and the 160 amp alt running at hwy speed= don't touch it for a while. :flamingdevil:

When the took it off there wasn't any movement. The alternator is getting hot with the hood open. Not burning but a uncomfortable to touch hot. When I took it off and moved it there wasn't any rattle inside. I'm going to be getting the one from the dealer on Tuesday they have it coming. I also replaced the belt just to see if the squeak away when I turn it off but it didn't do anything. Thanks for the help everyone. When I get the new one I'll give a update.


Mk

 

[mk_v]

The new alternator fixed the sounds and the squeak. Thanks for all the help everyone


Mk

 

[libertybob]

Warnings...

Auto parts sometimes give early warning signs that failure is imminent. The noises in the alternator were one such warning. When we listen and replace the part before failure, it is the least expensive way out. A failed alternator with a drained battery in the middle of the road results in a tow and replacement costs. So when parts start to say I am tired and need replacement, listen up! If we don't listen, we will wish we had. Examples, alternators, batteries, water pumps, fuel pumps, starters, brakes, etc.

 

[HoosierJeeper]

I think I'm having the exact same issue. Was yours pretty intermittent?
Did it sound like this?

You must be registered for see images attach

(more towards the end)
I could get a better vid if needed. But it's like a rattling sound and I put my stethoscope on the alt and that seems to be where it's the loudest. Looked into the AC clutch too.

 

[HoosierJeeper]

I also get that squeak when I turn it off.

 

[mk_v]

I also get that squeak when I turn it off.

Sorry for the late reply, I didn't know there was a post. The video didn't load on my end atleast so I couldn't hear the sound.


Mk