Replace voltage regulator, or whole alternator?

[StickMon]

When mine frazzed I took it out and shlepped it over to a local rebuilder.
4 hours and 150 bucks later it was done and I popped it back in.
He claimed to have put in a 160 A voltage regulator, but I really don't know what the heck is in there.
Ever since I've had slight rev drop when coming to a stop.
Voltage drops, too, but it's a chicken and egg thing.

Good idea to stick with Valeo.

Thanks for reminding me. Just bought the Valeo regulator to keep as a spare in case mine gets weird(er).

[pokeybritches]

Update: I went for a 30 min test drive last night. I had been having minor hesitation at low rpm since I can remember (well before the supercharger), but it's gone now. The engine is buttery smooth, like my M54 car. That tells me the alternator has been an issue for a long time. The rev dips at idle are gone too. All this adds up to a feeling of more power in the lower rpm. Before the repair the engine felt a little uncertain between 2k-3k rpm, like it was sorting itself out. Now it just goes. I'm happy it's fixed, but a little upset I unknowingly subjected the car to electrical torture for such a long time.

[pokeybritches]

Originally Posted by StickMon

Thanks for reminding me. Just bought the Valeo regulator to keep as a spare in case mine gets weird(er).

I definitely recommend it! You know a good bit about electricity, so you can imagine what it's doing to the car when it has a small scale brown out.

[StickMon]

Thanks for the update.
I suspect my new mystery voltage regulator has a slower "transient response" than the stock Valeo. That's one of the parameters that separates good voltage regulators from just good enough.
When the revs suddenly drop, the input voltage to the regulator drops, and it's too slow to be able to keep up.
Similarly, when you come off idle, the load suddenly increases, and again it can't keep up.
Not to throw gas on the flame war over auto parts store rebuilt alternators, but there are more variables than simply does it work or will it fail early.

[jdoublehcubed]

Jesus, 6 hours of labor? Is it really that bad, or is that just the shop raping pokeybritches?

I've done alternators before in around an hour (not on the Z4), 6 hours is what I would expect to take for the water pump.

Not questioning your shop decision, just curious, and I know how much it sucks to not have a lot of options for service. I once paid $800 installed for a set of OEM replacement springs, because one broke while I was away from home with no where for me to do it myself.

[Shipkiller]

Originally Posted by StickMon

Not to throw gas on the flame war over auto parts store rebuilt alternators, but there are more variables than simply does it work or will it fail early.

[Schlesien]

Originally Posted by jdoublehcubed

Jesus, 6 hours of labor? Is it really that bad, or is that just the shop raping pokeybritches?

I've done alternators before in around an hour (not on the Z4), 6 hours is what I would expect to take for the water pump.

Not questioning your shop decision, just curious, and I know how much it sucks to not have a lot of options for service. I once paid $800 installed for a set of OEM replacement springs, because one broke while I was away from home with no where for me to do it myself.

Frustration is the Mother of Invention😠

[RossBMWZseries]

Pokey I was aware you had this issue going on but I didn't know it was recent. So I spoke to a local Shop that rebuilds alternators. He quoted me $245 based on another BMW he had there. He stated that he would only use BRAND NEW OEM parts to repair my regulator. $245 doesn't sound bad for an OEM BMW alternator. What are your thoughts? He wants me to take him my alternator and battery so he can charge it. He said both have to be on par with each other. Guy had an accent and whatever he wouldn't say in English would say it in Spanish. I'm not too familiar with Spanish in the mechanic vocabulary

[Shipkiller]

Originally Posted by RossBMWZseries

He wants me to take him my alternator and battery so he can charge it. He said both have to be on par with each other.

Just remember, 'battery registration' is not required on the E85/E86, if that is what he is talking about.

[RossBMWZseries]

Originally Posted by Shipkiller

Just remember, 'battery registration' is not required on the E85/E86, if that is what he is talking about.

Right but no He didn't mention anything about the registration. I've been doing a lot of reading and based on the symptoms my car's been having I'm thinking it could be the voltage regulator. How can I possibly check and confirm what the issue really is?

[StickMon]

Try and cross him up. Ask him what brand of voltage regulator.
(The correct answer is Valeo)
If he passes the test, it sounds like a good deal.
I can't remember exactly, but I paid about $200 to get mine rebuilt with a mystery regulator.

[RossBMWZseries]

Originally Posted by StickMon

Try and cross him up. Ask him what brand of voltage regulator.
(The correct answer is Valeo)
If he passes the test, it sounds like a good deal.
I can't remember exactly, but I paid about $200 to get mine rebuilt with a mystery regulator.

Great idea StickMon, I'll do that. Pokey did state you were "smart on electronics" on another forum and from what I've read so far I can see why he made such comment. I took out my air filter box to have easier access to get to the alternator so I can take it to this shop BUT I'm not sure where the bolts/screws are. Any guidance on first step on how to proceed to remove the alternator would be greatly appreciated.

[StickMon]

I'm an Electrical Engineer for NASA/JPL.
Not exactly a Rocket Scientist, but I eat lunch with them.

This might help.

You got the air filter box off. That's half the battle.
Took me a while to figure out those rubber mounts.

The biggest challenge I had is once you "Release screw (1)"' which is actually a honkin' bolt, the alternator is still stuck.

"Screw (1)" goes through a tab on the block, then the alternator, then another tab on the block.
After you take the bolt out, the tabs are still squeezing the alternator, so it just rocks back and forth.
I had to go up from underneath with a big screwdriver and pry it out.

[Finnegan]

Originally Posted by StickMon

I'm an Electrical Engineer for NASA/JPL.
Not exactly a Rocket Scientist, but I eat lunch with them.

This might help.

You got the air filter box off. That's half the battle.
Took me a while to figure out those rubber mounts.

The biggest challenge I had is once you "Release screw (1)"' which is actually a honkin' bolt, the alternator is still stuck.

"Screw (1)" goes through a tab on the block, then the alternator, then another tab on the block.
After you take the bolt out, the tabs are still squeezing the alternator, so it just rocks back and forth.
I had to go up from underneath with a big screwdriver and pry it out.

Between you and Ship we have electronics covered in space, air, and sea (well, under the sea). Just need a land guy now!

FWIW, and unrelated to electronics, I think Pokey paid that much in labor due to the S/C which makes this a bear of a job. Best to install a new alternator before installing the S/C if the car isn't a really low miles I'd think.

[Schlesien]

When everything else fails take a dog for a walk

[RossBMWZseries]

Originally Posted by StickMon

I'm an Electrical Engineer for NASA/JPL.
Not exactly a Rocket Scientist, but I eat lunch with them.

This might help.

You got the air filter box off. That's half the battle.
Took me a while to figure out those rubber mounts.

The biggest challenge I had is once you "Release screw (1)"' which is actually a honkin' bolt, the alternator is still stuck.

"Screw (1)" goes through a tab on the block, then the alternator, then another tab on the block.
After you take the bolt out, the tabs are still squeezing the alternator, so it just rocks back and forth.
I had to go up from underneath with a big screwdriver and pry it out.

Yea no problem with the air filter box here, common, it's not rocket science
On a serious note, for the life of me, I cannot remove the damn belt!! After maybe using the f word 50 times, I decided to remove the tensioner but still no luck. I put the tensioner pulley back on. "Screw 1 has been completely removed. My only issue is removing the actually belt. Everything else sounds like a smooth process.

[StickMon]

Really? So, we're even. I had no problem getting the belt off.
See the last picture in post #1 here.
I have to use that because I can never remember how to put it back on.

But if you removed the tensioner and couldn't get the belt off, I must be missing something.
Can you elaborate?

[RossBMWZseries]

Lol you got me! Ok so I got the belt off, but I'm now stuck with the bolts behind the alternator. It says I'm supposed to unscrew nut 1 and the battery positive lead from the alternator. I can't seem to access that, and I have normal sized hands

I got it!!! I think I'm gonna go apply with NASA now I truly appreciate the help StickMon and Pokey. Just so we're clear, I didn't mean to thread jack here. I just thought It'll help others find it all on the same thread. Again thanks a bunch!

[RossBMWZseries]

Originally Posted by RossBMWZseries

Lol you got me! Ok so I got the belt off, but I'm now stuck with the bolts behind the alternator. It says I'm supposed to unscrew nut 1 and the battery positive lead from the alternator. I can't seem to access that, and I have normal sized hands

I got it!!! I think I'm gonna go apply with NASA now I truly appreciate the help StickMon and Pokey. Just so we're clear, I didn't mean to thread jack here. I just thought It'll help others find it all on the same thread. Again thanks a bunch!

My alternator seems to have a lot of "dust" going in. I found a lot of old engine oil dripping from the engine onto the big cover I removed to access the pulleys. I suspect this "dried up oil/grease-like residue" created this black dust and collected itself inside the alternator. Could this possibly be the issue causing my alternator to read low voltage?

[StickMon]

Probably not. The regulator is sealed in epoxy.
Everything else is low impedance and 14 V, so even if the goo is conductive you wouldn't notice any impact.
At least not until it catches on fire.
And don't worry about thread jacking. You're on topic.

[RossBMWZseries]

Understood. I dropped off the alternator and battery today at the shop I mentioned on one of the previous posts. I asked him about the parts brand he would use but he didn't know. He went on to mention all the OEM parts for other vehicle makes but he guaranteed me he would use OEM. If that's the case, $245-300 doesn't sound too bad. I'll pick it up Monday afternoon, reinstall everything and I'll post the updates on here.

[RossBMWZseries]

So the man from the shop calls me today to let me know that he "forgot" to call me on Friday to tell me that BMW doesn't make those parts for a 2006 Z4 anymore. BULLSHIT. I'm picking up my $100 deposit and taking my stuff elsewhere. I might even just buy an alternator from autozone for $300 and take a risk