2003 Z4 e85 2.2 alternator the same as 2005 2.0?

Jet

Member
Hi there everyone.

My sister has a 2005 bmw z4 2.0. Recently her alternator died. So found a new one on euro car parts for £166.

My alternator (bmw z4 2003 2.2) has also decided to kick the bucket. However according to euro car parts and gsf auto. The same one won’t fit my car. The price difference is astronomical one for mine costs around £400.

So my question is can I seriously not just use the same alternator as what I got for her car?

Please and thank you!
 
Jet said:
Hi there everyone.

My sister has a 2005 bmw z4 2.0. Recently her alternator died. So found a new one on euro car parts for £166.

My alternator (bmw z4 2003 2.2) has also decided to kick the bucket. However according to euro car parts and gsf auto. The same one won’t fit my car. The price difference is astronomical one for mine costs around £400.

So my question is can I seriously not just use the same alternator as what I got for her car?

Please and thank you!
Welcome aboard.
The alternators are different.
However, rather than buy a complete new one, have you considered just changing the diode/regulator pack on the back of it?

Like this:
https://www.ebay.co.uk/itm/275669379487
 
Hello there! Thanks for replying so quickly.

So if I bought the same one as my sisters I wouldn’t be able to install it?

I didn’t even think about that (or even know you could do it). Is it more likely for that to have died rather than the entire alternator?

To explain my car has been having a constant battery drain for a little while, I left her sitting for about 4 weeks while I went on holiday, when I got back I replaced the battery and kept driving, only to realise it wasn’t charging. (Volt meter is registering 11.6v when the car is running, measurements coming directly from the positive of the alternator)

Do you think changing the diode will fix it?
 
Jet said:
Hello there! Thanks for replying so quickly.

So if I bought the same one as my sisters I wouldn’t be able to install it?

I didn’t even think about that (or even know you could do it). Is it more likely for that to have died rather than the entire alternator?

To explain my car has been having a constant battery drain for a little while, I left her sitting for about 4 weeks while I went on holiday, when I got back I replaced the battery and kept driving, only to realise it wasn’t charging. (Volt meter is registering 11.6v when the car is running, measurements coming directly from the positive of the alternator)

Do you think changing the diode will fix it?
It worked for me, but I suppose there could be other reasons? That pack holds the brushes, regulator, diodes etc, so is most likely to be the issue. Possibly brushes worn.
it is fairly easy to remove the one on your alternator just to see if the brushes are knackered.
Of course, if you still have a battery drain it's not going to cure that. Have you found it?
Check the light in the centre storage isn't staying on.
 
Thanks for the advice. It’s much appreciated!

Might be a stupid question, but can I remove the back without removing the entire alternator? I’ve not ever done that part before.

Unfortunately I haven’t found the battery drain yet. Not entirely sure how to find it, however I haven’t thought of that centre console, I’ll give that a first try.
 
Jet said:
Thanks for the advice. It’s much appreciated!

Might be a stupid question, but can I remove the back without removing the entire alternator? I’ve not ever done that part before.

Unfortunately I haven’t found the battery drain yet. Not entirely sure how to find it, however I haven’t thought of that centre console, I’ll give that a first try.
Disconnect the battery first or you'll get a lump on the back of your head when it hits the bonnet. :roll:
If you remove the intake pipe you can quite easily get at the rear of the alternator. It's a bit fiddly to see where all the bolts are, but pretty logical.

When you open the storage compartment door there should be a lug sticking out of the bottom of it. This operates a microswitch to turn the light off. If anything gets dropped down there, then the door forced closed, it can snap the lug so the light stays on all the time.
 
The other option is to take up [ref]Umfaan[/ref]'s offer of a secondhand alternator. You could then perhaps fit a new pack to that and bolt the whole thing in.
 
You are all legends.

I will take the back off and see what it looks like on the inside. Hopefully good news and I can just replace the diode as you’ve said. I’ve just seen online that a faulty diode causes a constant battery drain too! So perhaps it’s two birds with one stone.

Otherwise I absolutely will check Umfaans offer!
 
Jet said:
You are all legends.

I will take the back off and see what it looks like on the inside. Hopefully good news and I can just replace the diode as you’ve said. I’ve just seen online that a faulty diode causes a constant battery drain too! So perhaps it’s two birds with one stone.

Otherwise I absolutely will check Umfaans offer!
Good luck.
Hope it works out.
 
Hello good people. Happy Sunday.

I've been trying to release this belt tensioner, but there just isn't enough space to do that! The T50 plus the ratchet wrench means I just don't have the ability to squeeze it in there.

Does anyone have advice on how I can get it to release? or get something to fit?

I'm using these heads https://www.amazon.co.uk/dp/B07M9ZF35W?psc=1&ref=ppx_yo2ov_dt_b_product_details
 
Jet said:
Hello good people. Happy Sunday.

I've been trying to release this belt tensioner, but there just isn't enough space to do that! The T50 plus the ratchet wrench means I just don't have the ability to squeeze it in there.

Does anyone have advice on how I can get it to release? or get something to fit?

I'm using these heads https://www.amazon.co.uk/dp/B07M9ZF35W?psc=1&ref=ppx_yo2ov_dt_b_product_details
Whip the radiator fan out.
As you look from the front there is a big fat plug and a torx screw on your left. On the right is a plastic rivet (prise the centre out first) and another smaller electrical plug.
Make sure the plugs are stowed out of the way then gently lift the fan up and out.
When you refit it, make sure the bottom of the fan shroud locates properly so it can't back back and forth.
 
enuff_zed said:
Whip the radiator fan out.
As you look from the front there is a big fat plug and a torx screw on your left. On the right is a plastic rivet (prise the centre out first) and another smaller electrical plug.
Make sure the plugs are stowed out of the way then gently lift the fan up and out.
When you refit it, make sure the bottom of the fan shroud locates properly so it can't back back and forth.

As always a scholar and a saint, Thank you very much I'll give this a try!
 
enuff_zed said:
As you look from the front there is a big fat plug and a torx screw on your left. On the right is a plastic rivet (prise the centre out first) and another smaller electrical plug.

Just a quick question, do I need to remove the front bumper? Or are you meaning as the bonnet is open, looking directly at the large black cover, I can remove it from there?

Apologies for the questions I'm a bit of a newbie!
 
Jet said:
enuff_zed said:
As you look from the front there is a big fat plug and a torx screw on your left. On the right is a plastic rivet (prise the centre out first) and another smaller electrical plug.

Just a quick question, do I need to remove the front bumper? Or are you meaning as the bonnet is open, looking directly at the large black cover, I can remove it from there?

Apologies for the questions I'm a bit of a newbie!
No, you have in fact caught me out. :D
Black cover has to come off first. Sorry..................... on my second pint in celebration of finally finishing a rainswept three day marathon vanos refurbishment. Never have I run so fast with so many tools. :roll:
 
enuff_zed said:
No, you have in fact caught me out. :D
Black cover has to come off first. Sorry..................... on my second pint in celebration of finally finishing a rainswept three day marathon vanos refurbishment. Never have I run so fast with so many tools. :roll:

That does sound like a pretty good reason to celebrate :lol: Thank you for the advice.
For anyone else having the same issue as me, I've found a nice guide showing a step by step!
https://www.pelicanparts.com/techarticles/BMW_Z4M/41-WATER-Engine_Cooling_Fan_Replacement/41-WATER-Engine_Cooling_Fan_Replacement.htm
 
Jet said:
enuff_zed said:
No, you have in fact caught me out. :D
Black cover has to come off first. Sorry..................... on my second pint in celebration of finally finishing a rainswept three day marathon vanos refurbishment. Never have I run so fast with so many tools. :roll:

That does sound like a pretty good reason to celebrate :lol: Thank you for the advice.
For anyone else having the same issue as me, I've found a nice guide showing a step by step!
https://www.pelicanparts.com/techarticles/BMW_Z4M/41-WATER-Engine_Cooling_Fan_Replacement/41-WATER-Engine_Cooling_Fan_Replacement.htm
That's a pretty good guide but there are no fasteners at the bottom, and if you simply unplug the sensor box on the side nearest to the expansion tank you can leave it attached.
 
No one has mentioned the option of having your failed unit rebuilt by a local starter and alternator service firm. Would mean taking it off the car if you can find a rebuild shop. I am lucky to have a guy fairly local to me who has rebuilt units for my Z3 and Z4 for circa £60 each.
 
Hello again everyone!

Right so after purchasing more tools, I was able to get a ratchet wrench and T50 low profile enough to release the belt tensioner and remove the alternator. Now that I know what I’m doing with the right tools, easily a 30 min/ hour long job.

I’ve replaced the Diode/regulator pack on the back. The previous one was quite worn and oxidised.

I then started up the car and the battery remained at a solid 12v, and while revving it would go up to around 14/15v. So seemed like the issue was fixed!

Until I wanted to drive the car later. I hopped into the car again, ready to go for a nice trip, only to be met with the Red battery warning sign on the dash. At that point I was too tired to diagnose again, but assuming the alternator is again not functioning.

Any thoughts? @colb what do they do when they recon the alternator other than replacing the Regulator?
 

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