Z3 2.8 Roadster alternator

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Koolflyer
Joined: Fri 05 Jul, 2013 16:51
Posts: 583

  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: 583

  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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  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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Koolflyer
Joined: Fri 05 Jul, 2013 16:51
Posts: 583

  Z3 roadster 2.8

Re: Z3 2.8 Roadster alternator

Post by Koolflyer » Wed 03 Jun, 2020 20:30

FYI, new 90amp alternator fitted, both drive belts replaced (power steering and air conditioning) plus both associated tensioners replaced after 137k. Awful bearing noise now totally gone! Car now back on the road.....and of course it's raining! :head:
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White

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