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Andy G

Alternators, I take it they shouldn't smoke?

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My Dads e39 528 is now running nicely however the battery light is fully on, new battery so thats one item discounted, however today we noticed that after a few minutes ticking over we had heat and smoke, looked like electrical burning/smoke so engine off and the alternator is quite hot, battery disconnected and car tucked away. Smoke was coming from the alternator so something in their has failed or seized. It is the original so maybe it was time for a change.

 

Looks fairly easy to do, but is it?

 

Any makes to avoid, I see from Eurocar parts there's RTX, Napa etc as well as Lucas and Bosch. I'm thinking Lucas at the moment.

 

 

Edited by Andy G

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45 minutes ago, Andy G said:

My Dads e39 528 is now running nicely however the battery light is fully on, new battery so thats one item discounted, however today we noticed that after a few minutes ticking over we had heat and smoke, looked like electrical burning/smoke so engine off and the alternator is quite hot, battery disconnected and car tucked away. Smoke was coming from the alternator so something in their has failed or seized. It is the original so maybe it was time for a change.

 

Looks fairly easy to do, but is it?

 

Any makes to avoid, I see from Eurocar parts there's RTX, Napa etc as well as Lucas and Bosch. I'm thinking Lucas at the moment.

 

 

 

Get OEM but refurbished and warranted

 

I used this guys as they're local to me but they ship out also

 

https://www.westlancsautoelectrics.co.uk/

 

Bosch is OEM IIRC

 

Whilst you're doing that; look to do the oil filter housing gasket (unless done recently) and change the belts too; it's all off/easy accessible when the alternators removed, so IMO, makes sense

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1 hour ago, Andy G said:

My Dads e39 528 is now running nicely however the battery light is fully on, new battery so thats one item discounted, however today we noticed that after a few minutes ticking over we had heat and smoke, looked like electrical burning/smoke so engine off and the alternator is quite hot, battery disconnected and car tucked away. Smoke was coming from the alternator so something in their has failed or seized. It is the original so maybe it was time for a change.

 

Looks fairly easy to do, but is it?

 

Any makes to avoid, I see from Eurocar parts there's RTX, Napa etc as well as Lucas and Bosch. I'm thinking Lucas at the moment.

 

 

If it smoke it's gone. My ended exactly same way, barely charged anything and started to smoke.

Mine is diesel and originally having Valeo alternator, I replaced my with Valeo reconditioned unit on exchange basis. Found seller on eBay. It had warranty with it, prepaid postage label to get old alternator returned. So far all good, replaced on beginning of April, since that did close to 10k miles. 

 

Have a look what make is your alternator, and you will know which brand is OEM, or most likely as Dan said Bosch will be OEM, but Lucas is well known name as well and they do a lot of OEM parts as well for wariery car manufacturers. 

Plus check what amperage is your current alternator, most likely you don't want to degrade for smaller unit, going for bigger is ok, until it still match fixing points.

Edited by Ray112

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41 minutes ago, AdamB said:

Just a thought, could it be the dust/leaves etc from the cooling duct getting scorched?

What ever it is, it's too late anyway. Alternator is toast now if it's getting hot really fast and smoking.  But I doubt it's much to do with cooling duct, mine started to get hot in couple minute and smoke, while diesels don't have air duct at all, it's just open back air cooling. Most likely it's just age that kills them, copper windings possibly having short circuit somewhere, which is cause for heat and smoke. On my alternator those copper windings were turned totally bluish from heat.

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cheers guys, yes it was worrying, battery light went out briefly, made some 'odd' noises then came back on, then started to smoke! 

 

80amp and I'll order one today

Edited by Andy G

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Could well be leaves blocking the air duct causing windings to overheat.  There's a recent post on a grille retrofit to avoid this.  Actually oem is either bosch or valeo.  There are many posts on this and the output current ratings vary as well from 80 or 90 to 130 or more amps from recollection.  I've been researching for when my alternator needs doing.  Mine is only 90a I think not sure if changing for a more powerfil one is worthwhile .

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24 minutes ago, Dbcrd said:

Could well be leaves blocking the air duct causing windings to overheat.  There's a recent post on a grille retrofit to avoid this.  Actually oem is either bosch or valeo.  There are many posts on this and the output current ratings vary as well from 80 or 90 to 130 or more amps from recollection.  I've been researching for when my alternator needs doing.  Mine is only 90a I think not sure if changing for a more powerfil one is worthwhile .

If alternator start smoking couple minutes after starting engine, it won't be cooling issue. There's internal damage to it. Normally they don't turn up so hot in so short time. And once it's overheated, it's defective. Installing mesh infront of air duct could be good protection for next alternator, to keep cooling duct clean and unblocked, but hoping that cleaning duct will bring this one back to life is hopeless.

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7 hours ago, Dbcrd said:

i agree.  Any views on amp rating and bosch vs valeo

If you can upgrade amps, why not. And when I was looking for alternator, for my diesel it was only Valeo available or some unknown makes. Bosch might be used for petrol engines I believe. Not sure if diesels have different fixing points or wiring connector to petrol, but diesels (M57 engines) definitely don't have air duct for cooling attached to it, so back of alternator is different. 

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I did toy with an amp change but this one is a Bosch unit, the original and is an 80 amp item so I'll replace like for like. Not sure if there's any point in fitting a higher output one though.

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2 hours ago, Andy G said:

I did toy with an amp change but this one is a Bosch unit, the original and is an 80 amp item so I'll replace like for like. Not sure if there's any point in fitting a higher output one though.

 

Shouldn't really matter; but more amps is better power; but like for like will be fine :) 

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If you haven't added any equipment which needs fair bit of power, you can definitely replace like for like. Higher amperage output usually was used on cars with heated seats etc.

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well that alternator is done, fairly straightforward but, the hose between the MAF and the TB is perished, and as I've disturbed it all, it idles low now and stalls when cold, so new intake bellows ordered.

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9 minutes ago, Andy G said:

well that alternator is done, fairly straightforward but, the hose between the MAF and the TB is perished, and as I've disturbed it all, it idles low now and stalls when cold, so new intake bellows ordered.

 

Common issue; not expensive to replace thankfully :) 

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