Alternator question

[john2k]

Hells bells
For sure I can’t see any significant damage that you have done from your photo.
I would, however double check the suitability of the replacement for your car.
Tell us more about what you are doing, please? Are you replacing the alternator because of a dynamo conversion, has there been a change in polarity or direction of rotation?
John

It is marketed as 100% match for my vehicle with the OEM reference numbers etc all matching up. I don't think it's genuine Lucas brand either because it's marketed as aftermarket but seems to have a label on it that refers to the Lucas alternator model number. everything lines up perfectly and the connectors all connect fine. The seller seems to have sold a hell of a lot of the units on eBay. Their eBay feedback seems to be 100% but google reviews arn't so great with most people complaining of failures after a very short time.

In regards to what i'm doing, my orginal alternator has cover 180k+ miles and I just wanted to be safe and change it as preventative maintenance as i've heard a lot of the alternators on my model tend to fail. So I had an option between a Denso OEM aftermarket for £230 or this aftermarket for £130 so I bought this aftermarket. I disconnected the negative terminal on the battery, then removed the positive connection on the alternator followed by the connector. Then I removed the bolts holding the alternator in and jiggled the old one out. Then transfer some mounting brackets over from old to new and jiggled the new one back in. When I put it all back up, I noticed my idler pulley bearing was a bit noisy so ordered a new idler pulley and ordered a new OEM belt too since old one is old. So I changed the idler pulley and installed the new belt. Connected up the battery again, went to start the car and the noise was extremely loud. At first like a very loud screaching sound followed by a whine then all the smoke.

The only other thing I can think of is if it could be the new idler pulley but I spun that pulley by hand and it spins freely and isn't stuck or anything.

 

[JohnD]

the noise was extremely loud. At first like a very loud screaching sound followed by a whine then all the smoke.

The only other thing I can think of is if it could be the new idler pulley but I spun that pulley by hand and it spins freely and isn't stuck or anything.

makes me think of a seized bearing turning in its housing.

you should find it easily because it will get very hot very quickly.

 

[john2k]

makes me think of a seized bearing turning in its housing.

you should find it easily because it will get very hot very quickly.

I turned it off and disconnected battery straight after I noticed the smoke. When I looked in the engine bay it appeared the smoke was coming from the alternator. At first I thought could it be the new idler pulley or the new belt but idler pulley spins freely. The belt looks fine and it's under tension from the tensioner. If belt was smoking will smoke be coming from alternator?

 

[JohnD]

you sure it wasn't the squeal of a slipping belt under load?

a turning bearing will smoke as it burns off the grease. but not for long.

 

[john2k]

you sure it wasn't the squeal of a slipping belt under load?

How will I be able to tell if it's a slipping belt? It didn't sound like a slipping belt it was extremely loud. The belt is on nice and firmly and all the grooves are slotted in.

a turning bearing will smoke as it burns off the grease. but not for long.

Smoke looked like it was getting worse and denser and I didn't want to risk anything else damaging so I just turned it off. Should I try running it again and see if the smoke disappears?

 

[Burnerman]

Take the belt off and try to spin the alternator in the appropriate direction of rotation.
Feel for any resistance.
If all is ok, you’ve nothing to lose with another start up, looking very carefully for the smoke trace.
John

 

[Mottie]

With the belt off, can you turn the alternator? If it had shorted out it would surely keep burning when off as it’s directly connected to the battery live. Are you sure you’ve routed the belt properly? It’s not that smoking, is it?

 

[john2k]

Take the belt off and try to spin the alternator in the appropriate direction of rotation.
Feel for any resistance.
If all is ok, you’ve nothing to lose with another start up, looking very carefully for the smoke trace.
John

OK, I will try this tomorrow while I wait for a return label from the seller. If it spins freely by hand then when I start it up even if it's smoking a lot should I shut it off or just wait? So even if it's smoking just let it run?

With the belt off, can you turn the alternator? If it had shorted out it would surely keep burning when off as it’s directly connected to the battery live. Are you sure you’ve routed the belt properly? It’s not that smoking, is it?

Before I installed the belt I did try and spin the alternator pulley by hand and it was spinning fine. The belt is definately routed correctly, i drew a diagram before hand and made sure it's exactly the same route. How can I tell if it's the belt thats smoking or the alternator?

I read in some places that apparently new alternators may smoke a little in the beginning but the seller claims these are bench tested under load before dispatch, so if it was going to produce smoke it would have happened at the bench test wouldn't it?

 

[Burnerman]

Never in my life have I seen a smoking alternator! Shut the thing down promptly if it does it again.
I don't suppose you had the time to see if the charge light had gone off?
John

 

[Mottie]

Before I installed the belt I did try and spin the alternator pulley by hand and it was spinning fine. The belt is definately routed correctly, i drew a diagram before hand and made sure it's exactly the same route. How can I tell if it's the belt thats smoking or the alternator?

I only say that because I once had fitted a belt properly according to how it was routed but I had looped the belt over a stud as well so it was running on that. It didn’t half make a noise and produce some smoke! I'd be tempted to run it again but be ready to switch off and disconnect the battery.

 

[john2k]

Never in my life have I seen a smoking alternator! Shut the thing down promptly if it does it again.
I don't suppose you had the time to see if the charge light had gone off?
John

No I didn't get round to checking that as I panicked with the smoke and noise. If it's not the alternator and is the belt should smoke have been coming from the alternator itself? I'm almost 100% sure the smoke looked like it was coming from the alternator area.

Is there a easy way to tell if it's belt slip that's causing smoke and noise?

I may just return it and order myself a genuine Denso one then if it does that again then I know something I did

 

[john2k]

I only say that because I once had fitted a belt properly according to how it was routed but I had looped the belt over a stud as well so it was running on that. It didn’t half make a noise and produce some smoke! I'd be tempted to run it again but be ready to switch off and disconnect the battery.

I will double check belt route tomorrow in the day time.

If it is the alternator then what exactly could be happening to create smoke and noise ?

 

[Mottie]

Something jammed inside? I wouldn’t think it would turn and make noise though. I still suspect the belt. Start it and watch - you have nothing to lose.

 

[john2k]

Something jammed inside? I wouldn’t think it would turn and make noise though. I still suspect the belt. Start it and watch - you have nothing to lose.

I will check tomorrow and report back

 

[john2k]

If lets say the smoke and noise was from a belt issue, the fact that this much smoke was generated could it have damaged anything?