Alternator problem
 

Hi have 05 x5 4.4. When i first start driving in the morning in about 10 minutes
I get 4x4 light and flat tire lite. I had codes read and they point to voltage being low.
So i started to monitor voltage by a voltmeter.
When i start the engine in the morning a voltmeter shows 12.55. After about 10 minutes i hear some noise from the alternator and voltage jumps to 14.5. At this point engine rpms drop momentarily. Feels like the alternator was not engaged and suddenly it got engaged. If is start driving now i never get 4x4 light. Any idea why is it engaging so late? Could it be that the belt is loose or is there
A built in mechanizm in the alternator to activate/deactivate it? Or is it just alternator gone bad?

Once it "activates" and voltage reaches 14.5 it is good for rest of the day. I can shut down the engine and then start it and voltage is good. It only happens after the car has sat overnight.

Really looking forward to hearing from you
Thanks

I think your voltage is too high for an X5. The usual voltage is in the 13.85V range for the highest point with these alternators. I would suspect the regulator pack but would change the whole alternator if I were doing it. In your case with the 4.4 engine that is not a cheap repair.
GL

I just want to be sure its the alternator. Anybody else with same
Symptoms? Whu would it be expensive? I s aw some rebuilt alts.
For less then 200 and my mechanic says he can swap it in an hour.

Does he know it is water cooled?
$200 seems a little low but maybe you're getting a deal somewhere. I would be looking at a specialist supplier such as Bavauto or the like to be sure I was getting the proper part and it was not some thrown together reman such as those your get from Autozone etc. I have heard nothing but tales of woe from people who have fitted these parts and had to go through the fit - remove- replace - fit remove-... dance several times before they gave up and bought from specialist. While the companies involved did honor their warranty each time there was still the labor cost or waste of time involved performing "field quality control" testing.

I looked and i did not see any water hose going in the alternator.
Are you sure 05 4.4 has watercooled alt. ?

You're correct! It seems to be a standard alternator so it is no big deal. (I checked on realoem.com) Puts a whole different light on things.

I guess this is what threw me??

http://www.xoutpost.com/bmw-sav-foru...lternator.html

What do you think about Bosch rebuilt ones from reputable part dealers?

Depends on who did the rebuilding and where. Every reman I have read about that had problems seemed to have been rebuilt in Mexico. There may actually be some quality rebuilds from there but.....
Ask who did the rebuilding and then check them out as much as possible online. It is so hard to make a buck in today's market that retailers are being forced into using suspect suppliers just to compete.
I have read about big name electronic component supply houses getting caught out with batches of look-alike Chinese made junk. (Pun intended.) It cost them mega $$$$ to put right and their good name was ruined.

i would say to get a lifetime warranty one if it breaks again at least you can get another one free, (only pay for the labor), mine was with water cooler for my 01, paid 345$ at riebes auto parts with lifetime warranty.

goodluck,

my mechanic is getting eom one from dealer fro 600 something dollars
he is saying he has to remove radiators upper hose to get to it.
which means new coolant and coolant bleeding. Wonder if its possible to
get to the alternator without messing with coolant hoses.