Help! Bad Alternator, I think (DT? Anyone?)

[Eric S.]

After the recent Summertime fiascos (see my recent threads) with (a) the Sears battery vent not being hooked up (and leaking) and the attendant body shop visit, (b) the $1375 A/C compressor replacement, and (c) most recently the multiple Midas visits regarding balance of Kumho ASX'S (and resolving it just last Thursday via installing Dunlops), a NEW problem presented itself tonight: alternator going bad!!

An embarrassing jump start in front of the local NAPA got me home (10-minute drive). Just before I got home, various warning lights began to illuminate (DSC, brake, dim display, etc, but not an alternator light). The car would not re-start once I shut it off. It just clicks, along with all cabin lights and other lights working OK.

Symptoms:
- I measured the voltage at the batt with the car off and I got 11.3V to 11.4V.
- I jump-started the car with my Schumacher battery charger/starter, but the voltage read no higher than the 11.4 once I disconnected the charger, and began to slowly decrease from there as the car ran.
- The battery is less than one month old, purchased from the dealer.

Seems to me I need a new (expensive & water-cooled M62TU) alternator (the original was replaced under warranty @ 58K miles, I'm now @ 130K). Agreement? Anyone? But if the alternator's bad, then why doesn't the alternator warning light illuminate when the engine is running? It lights when first turning the key (along with all of the other lights). Before I sink major $$$$ (and knuckle skin) into a new alternator, can someone help me confirm that's the most likely culprit?

Also - Bentley indicates I'll need to remove the fan & shroud to get access to the alternator. Anyone else know any tips/tricks to the job?

AAAAAARRRRRRRRRRRRRRRRRRRRGGGGGGGGGGGHHHHHHHHH!!!! !! :

I am 'THIS' close to being "over" this car (and driving it off the bridge), so I can imagine how fed up my wife must feel, but God bless her, she's kept her comments to herself....

[Dirty_Tool]

ya eric.. sounds like failed alternator. Just make sure cable connections are OK. Especially if you had body work back there.. make sure they didnt remove the ground cable then paint the body where it attaches then reattach over paint. Ive seen that a few times now. Other than that if you jump start a car and it wont stay running then it isnt charging. As long as the alternator is getting excited by the D+ exciter circuit and has of course power and ground, then you prob just have a bad alternator.

Sorry Dude.

[wcleafs]

Yikes!!!:

Check a couple of things before you replace the alternator.

1. Take the battery out and put it on a tester see if you have any shorted plates. I dont know the age of your battery but older batteries can have an accumulation of crud pile up at the bottom and this can eventually short a plate to another.

2. If possible can the voltage reg circuit in the alternator be replaced by itself?
if it can be it is a cheaper fix then replacing the whole core.

Ideally with the car running the voltage should be around 13.5 to 14 VDC, sounds like a dead alternator but I have seen the battery issue before and when they rebuild an alternator all they usually do is clean up the windings and replace the diode pack (voltage reg circuit) and then charge you big bucks.

Good Luck! own a Bimmer and have a big wallet.

[Eric S.]

Originally Posted by wcleafs

Yikes!!!:

Check a couple of things before you replace the alternator.

1. Take the battery out and put it on a tester see if you have any shorted plates. I dont know the age of your battery but older batteries can have an accumulation of crud pile up at the bottom and this can eventually short a plate to another.
.

As mentioned, the battery is just under one month old. Even if the battery were bad, I don't see how it could keep me from seeing 13.5 to 14.0V with the car running if the alternator was any good.

As far as the ground attachment, I checked that and there was no re-paint done in that area, just the bottom of the trunk and underneath the battery.

I'll be checking around today to see what my options are. I'm sure they'll be few and expensive. I think I'll try to find a good used Honda Civic Si or Acura RSX Type S. I am so OVER this money hole....

[rej487]

Originally Posted by Eric S.

As mentioned, the battery is just under one month old. Even if the battery were bad, I don't see how it could keep me from seeing 13.5 to 14.0V with the car running if the alternator was any good.

As far as the ground attachment, I checked that and there was no re-paint done in that area, just the bottom of the trunk and underneath the battery.

I'll be checking around today to see what my options are. I'm sure they'll be few and expensive. I think I'll try to find a good used Honda Civic Si or Acura RSX Type S. I am so OVER this money hole....

You're almost there man! There most likely will not be more expensive repairs beyond the alternator.. don't fix everything then sell it to someone else so they can enjoy all your hard worked money!

[Eric S.]

Originally Posted by rej487

You're almost there man! There most likely will not be more expensive repairs beyond the alternator.. don't fix everything then sell it to someone else so they can enjoy all your hard worked money!

You know, I'd be tempted to go along with you, but instead I am petrified by the major-$$ things that haven't YET broken that usually do:
- Pixels out in dash display
- Catalytic convertors (I'm still on my originals)
- DSC module (often fails on '99 540's)
- Water pump, etc. (I've got the new-design post 2001 hose set-up, but my water pump looks old).
- Heater hoses throughout
- Rear wheel bearings
- Timing belt housing/cover gasket
- Rear main seal
- Clutch

No problems yet on any of the above, so I see many $$thousands$$ in the above items waiting to break down....

[LOS]

I'll be checking around today to see what my options are. I'm sure they'll be few and expensive. I think I'll try to find a good used Honda Civic Si or Acura RSX Type S. I am so OVER this money hole....[/QUOTE]


I'm beginning to think these cars are not meant to be daily cars once you hit 100k on them unless you can afford the maintenance. I do think you should keep your car Eric and as you mentioned buy a Honda as a daily car if you can afford it. As you probably know, I have 3 cars and my 88 Pontiac Fiero GT is my daily car now. That sucker is still going strong and looking almost new. My other two cars are for pleasure. You appreciate the cars even more.

I'm glad you have taken the time to list all the problems you have encountered along the way. I remember you when you first bought the car. Your threads will help others deciding wether to buy a car with 100k miles or more on them. Chin up and keep that car. You'll fall in love again once you drive it once a in while!

LOS

[saltshaker185]

sounds like your alternator... i wouldnt spend the money for a brand new one... just hit up the salvage yard yo!

[Eric S.]

Originally Posted by saltshaker185

sounds like your alternator... i wouldnt spend the money for a brand new one... just hit up the salvage yard yo!

Good idea - I'll check that out. meanwhile, I've found a local place that will rebuild my alternator for about $250 and offer a lifetime warranty on it.

Los, man, I really appreciate your insights, and yes, there are cars that i've owned that I wish I could have back, but I need to have a reliable daily driver, and I don't really want to have a depreciating car in the garage that is not being used regularly. I once had a 1972 Corvette that saw occasional use, but that was OK as the car was appreciating with each year.

Stuff breaks a lot less when the car isn't driven in searing heat nor freezing cold.

I think I'll go check out a Honda Fit...

[a1artem]

guys i think you are right when a car hits more than 100 k it would be a disaster. i got 2001 740i sport package bought it about 1 year ago with 92k on it. now im 109k ,spent about 5 grands to fix the whole cooling system ,suspension parts were changed ,intake manifold gaskets (1400$). after all that i thought finally i can fully enjoy that black beauty but i was wrong i have problem with battery charging got a brand new battery 1 months old ,probably the alternator went bad so i dont know what to do with that crap again im exausted by spending money non-stop

[LOS]

It could be the alternator or maybe not... The other possibility is that you have a short somewhere which draining your battery. Check for interior lights, and the cigarette lighter and the sun visor. There is a bulb that may be stuck even if the visor is raised up! Most of the times is the cigarette lighter. Also check the trunk. You may have to take it a shop and trace the short!

LOS

[LOS]

It could be the alternator or maybe not... The other possibility is that you have a short somewhere which draining your battery. Check for interior lights, and the cigarette lighter and the sun visor. There is a bulb that may be stuck even if the visor is raised up! Most of the times is the cigarette lighter. Also check the trunk. You may have to take it a shop and trace the short!

LOS

[a1artem]

well i checked the voltage on the battery with the engine running there was no charge at all so i think the only problem was the alternator .Does anybody know where i can buy the cheapest one ?i checked the autozone but i thought it was expensive one around 500$ duralast brand

[Eric S.]

Originally Posted by a1artem

well i checked the voltage on the battery with the engine running there was no charge at all so i think the only problem was the alternator .Does anybody know where i can buy the cheapest one ?i checked the autozone but i thought it was expensive one around 500$ duralast brand

Re. the alternator, what is the year and model of your car? If you have a 1999 or newer 540 (as I did) your options are few because the geniuses in BMW engineering felt that a water-cooled alternator would be a fun thing to have BMW customers field test for them. Contrary to my ranting O.P., I could NOT get my alt rebuilt and ended up buying a rebuilt one from alloemautoparts.com for $382, plus $110 core.

As many of you now know, the trauma of having my 540 on jackstands for 3 weeks while trying to resolve the alternator was too much, and I decided to sell the thing after I replaced the alt, at 130K miles. M3UOND bought it from me and drove it fairly trouble-free to about 150k whereupon he had to invest about $4k to $5k in repairs like radiator, water pump, valley pan gasket, etc, etc, etc,.

I regrettably replaced my 540 with a 2003 Maxima 6-speed, which turned out to be a HUGE piece of dung, so last December I jettisoned the Maxima and bought a 2006 Accord V6 EX-L and could not be much happier! I finally have my life back! (but secretly I'd really LOVE to get my hands on a new 335 or E46 M3).....

[Karluver]

Hi guys,
Let me tell U my experience. I tried to stop my 320i after 1/2 hr of shopping and couldn't start it after 2-3 tries. The damn "service engine soon" symbol came on. Finally I got it started. The next day, I was able to start it and took it to my mechanic. To my surprise, the "Service Engine Soon" disappeared. But when my mechanic tried to re-start it and get it inside the bay, the engine was turning quite slow. My car (2001) has about 65K miles on it. His diagnostic machine ($65 for using this) tells I have a faulty intake cam sensor that cost $160+$80 labor. The battery is weak, but a load test proves that it is not being charged, an OEM alternator costs $440.+$180 labor. Couple of belts $80. My wallet is $1,200 lighter after all said and done.
The Bosch alternator has such a poor design that it doesn't have a fan blade built in to cool it, instead it has a hose to feed cool air. Can't believe an alternator in a BMW can't last 7 years, while the ones in Japanese cars can last the car's life. If the alternator is not charging, why there is no warning light ?? (My 320i doesn't have a voltmeter in the cluster to tell the voltage.)