Z3 2.8 Roadster alternator

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Koolflyer
Joined: Fri 05 Jul, 2013 16:51
Posts: 582

  Z3 roadster 2.8

Z3 2.8 Roadster alternator

Post by Koolflyer » Sun 17 May, 2020 18:16

Guys, my alternator bearings have been running noisily for a long time, so now the car is back on SORN now is the time to replace it along with the belt and A/C belt. I've got the old Bosch alternator off, and although difficult to read think it's a 14v 80amp (poss 90amp?) For my car there are 80/90 & 120amp units.

Question: As I'm not an electronics expert does it matter if I replace it with either an 80 or 90amp alternator as it's hard to see from the old one? :rtm:

Thanks
KF
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White

Mike Fishwick
Joined: Fri 19 Jun, 2009 11:27
Posts: 2039

  Z3 roadster 2.8
Location: Daglan, France

Re: Z3 2.8 Roadster alternator

Post by Mike Fishwick » Mon 18 May, 2020 09:09

I doubt if you would notice any difference, as the alternator - like most Z3 bits - is a standard type, used on many E36 models.

Are you sure that the noise is due to the alternator bearings? The belt tensioner bearings usually become noisey first.
A Z3 is not just for Christmas - it's for life!

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Koolflyer
Joined: Fri 05 Jul, 2013 16:51
Posts: 582

  Z3 roadster 2.8

Re: Z3 2.8 Roadster alternator

Post by Koolflyer » Mon 18 May, 2020 14:16

Thanks Mike for that. My 'indi' thought it probably is the alternator bearing, however after some reading up, I too am wondering whether the belt tensioners are showing their age. Mileage 136k so I have now ordered a new 80amp alternator (which I have now confirmed was on the car, labelled 1997 which ties up), both belts (Alt/water pump belt, and air con belt) plus both associated tensioners now I'm doing the job.

Thanks again
KF
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White

Mike Fishwick
Joined: Fri 19 Jun, 2009 11:27
Posts: 2039

  Z3 roadster 2.8
Location: Daglan, France

Re: Z3 2.8 Roadster alternator

Post by Mike Fishwick » Mon 18 May, 2020 22:13

My air con belt tensioner got quite noisey at about 130,000 miles too. Replacement of both tensioners would seem to be a good idea at this kind of mileage.
A Z3 is not just for Christmas - it's for life!

LaRy
Joined: Mon 12 Nov, 2018 17:47
Posts: 56

  Z3 roadster 2.8

Re: Z3 2.8 Roadster alternator

Post by LaRy » Tue 19 May, 2020 07:41

Hi, I've been changing the tensioner and must tell you that the quality today is very poor, even if they are looking the same. I got a couple of tensioners making noise from the bearing of the tensioner arm also making a poor tensioning job. If you buy a BMW origin tensioner, they want you to replace the complete solution to a hydraulic one. Very expensive.
In your case, with my experience, I would only replace the tensioner wheels.

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Koolflyer
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Posts: 582

  Z3 roadster 2.8

Re: Z3 2.8 Roadster alternator

Post by Koolflyer » Wed 20 May, 2020 23:16

Thanks for the input all, much appreciated. A slight update to the alternator for you. The German motor factors supplier who I have ordered the parts did confirm that some early cars were infact fitted with an 80amp version, but recommended a 90amp, which does tie up with Real OEM for my particular car. Additionally, the helpful chap at Sytner (Leicester) said BMW recommend either an 90 or 120amp now. So a 90amp is hopefully winging its way from Berlin. plus the other bits.

KF
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White

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