Bmw alternator question
Ok so my alternator just went out on my bmw and i need to know what alternator to get, i know mine is water cooled and i know the amps for the alternator that is in the car but the problem is the guy that i purchaced my car from just replaced the alternator with a random one without taking into consideration what the amps on the old alternator was, now i can't just put the same one in that the car already has because as far as i know it currently has the wrong type in.
My car has 211000 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
Hello, thank you for writing in. You will want to go with what they call an "OEM" (original equipment manufacture) part. This just means that the company which is producing the part uses the manufacture’s design, and it should be the exact type (or upgraded version of) the exact alternator that came with the car. There are going to be a wide variety of alternators that will work for you car, but an OEM part will assure the mounts fit and the power ratings are equivalent. While we can not advise you on the exact part or company to purchase it from, a search with the letters "OEM" should bring up what you are looking for. When purchasing a part, typically it is best to go with a middle priced replacement unless going to upgrades (say you power a lot of electronics or sound systems). For more help replacing the alternator, contact our service department.
How to Identify and Fix Common car Problems ?
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The average cost for a BMW 745Li Alternator Replacement is between $1,424 and $1,574. Labor costs are estimated between $187 and $236 while parts are priced between $1,237 and $1,338.
Blown Fuse
As an electrical component, your alternator has a fuse. Your BMW has numerous fuses, each of which is linked to a particular component. These fuses operate in the same way as any other fuse.
Charging output can be tested on a vehicle with a digital voltmeter. A good alternator should produce about 13.5 to 14.5 volts with the engine idling. If the voltage reading is low (12.5 volts or less), it indicates a charging problem but does not tell you what`s causing it.
Alternators can average anywhere from $100 to $350, depending on the model. In most cases, costs will average between $350−400 for the alternator replacement if no other parts need to be changed. Add another $20 to $50 to your bill if the serpentine belt has to be replaced as well.
One way is to use a voltmeter. If the alternator is not outputting enough voltage, then it is most likely bad. Another way to test the alternator is to start the car and then turn on all of the lights. If the lights dim, then that means the alternator is not charging the battery properly.
The battery terminal charging voltage must be less than 14.7 volts to prevent excessive gassing. Charging voltages over 14.7 volts can prematurely dry the battery by boiling out electrolyte, and increase risk of a battery hydrogen gas explosion.
For battery charging to occur, the alternator`s voltage must exceed the battery`s voltage. Alternator may not generate sufficient charging voltage until alternator speed is greater than about 2000 RPM.
A good alternator should maintain battery voltage between 13.9 and 14.8 volts (14.2 is optimum). Even worst-case, with all accessories turned on, there should be at least 13 volts at the battery.
The average cost for a BMW 328i Alternator Replacement is between $635 and $1,039. Labor costs are estimated between $118 and $148 while parts are priced between $518 and $890.
Labor costs are estimated between $136 and $171 while parts are priced between $345 and $784.
Most alternators last between 80,000 and 150,000 miles, or about seven years.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Bmw alternator question
ANSWER : Hello, thank you for writing in. You will want to go with what they call an "OEM" (original equipment manufacture) part. This just means that the company which is producing the part uses the manufacture’s design, and it should be the exact type (or upgraded version of) the exact alternator that came with the car. There are going to be a wide variety of alternators that will work for you car, but an OEM part will assure the mounts fit and the power ratings are equivalent. While we can not advise you on the exact part or company to purchase it from, a search with the letters "OEM" should bring up what you are looking for. When purchasing a part, typically it is best to go with a middle priced replacement unless going to upgrades (say you power a lot of electronics or sound systems). For more help replacing the alternator, contact our service department.
Read Full Q/A … : Bmw alternator question
Alternator belt or whole new alternator?
ANSWER : Hi There,
If the diagnosis was that the battery is being overcharged, you may have a faulty voltage regulator that could be allowing the alternator to supply too much amperage to the battery resulting in the battery never maintaining a consistent charge as it is designed to. The voltage regulator is a unit that regulates the charging of the battery by the alternator. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. A common sign of this is usually the acid inside the battery boiling causing the battery to swell. You may also smell a bit of smoke due to things potentially getting too hot. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.
If the diagnosis was that the battery is being overcharged, you may have a faulty voltage regulator that could be allowing the alternator to supply too much amperage to the battery resulting in the battery never maintaining a consistent charge as it is designed to. The voltage regulator is a unit that regulates the charging of the battery by the alternator. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. A common sign of this is usually the acid inside the battery boiling causing the battery to swell. You may also smell a bit of smoke due to things potentially getting too hot. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.
Read Full Q/A … : Bmw alternator question
How much oil needs to leak into an Alternator to cause the Alternator to go bad
ANSWER : It would be difficult to say exactly how much oil it would take to cause the alternator to fail. However, oil leaking on the alternator due to leaking valve cover gaskets can cause it to fail. It seems as if the technician who is servicing your vehicle may not have performed a courtesy inspection to check for other potential issues prior to starting the other repairs you had requested. I would recommend having the alternator replaced if it has oil leaking on it as well as resolving the valve cover gasket leak to prevent it from happening again. You may try to use a different mechanic who is more upfront and honest in the first place. Consider YourMechanic as services such as this can be completed from your home or office.
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my battery kept draining until i bought a new alternator and battery. i have tightened the belt on the alternator but it still die
ANSWER : Hi there. The best way to diagnose why a battery would constantly drain is to review it’s job and how it is recharged. The battery is responsible for powering all electrical systems until the vehicle is started. At this point, the alternator takes over and also continually charges the battery while the vehicle is in use. A battery will drain when one of two things occurs. First, a battery will drain if it is constantly in use; supplying power to an electrical component even if the key is not in the ignition. Second, the battery will eventually die if the battery is not being charged frequently. However, since this is happening every two days, my initial thought would be that some electrical component on your 86 Olds is continuing to draw power from the battery. This is known as a parasitic drain. The best way to determine the source of this battery issue is to have one of our professional mobile mechanics come to your location and complete a battery will not hold a charge inspection.
Read Full Q/A … : Bmw alternator question
Battery good, alternator good, brand new alternator cable, still not charging.
ANSWER : Hi There,
The first diagnosis of the bad voltage regulator is likely the cause of your charging system not properly charging the battery. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. In some cases when a battery is too weak or damaged, it may no longer hold a charge for any length of time, in which case the alternator may be doing its job, but the battery is just simply too weak to hold a charge. In either case, I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.
The first diagnosis of the bad voltage regulator is likely the cause of your charging system not properly charging the battery. When the voltage regulator is not working properly, this may result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. In some cases when a battery is too weak or damaged, it may no longer hold a charge for any length of time, in which case the alternator may be doing its job, but the battery is just simply too weak to hold a charge. In either case, I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.
Read Full Q/A … : Bmw alternator question
Will your mechanic diagnose and confirm the problem first before installing any new parts, e.g., alternator?
ANSWER : Hi There,
Yes, our mechanics will come to your location to perform a diagnostic test on the vehicle to properly determine what the cause might be. If it is in fact your alternator, you will be notified prior to any work being performed on the vehicle and given a quote for the parts and labor.
Yes, our mechanics will come to your location to perform a diagnostic test on the vehicle to properly determine what the cause might be. If it is in fact your alternator, you will be notified prior to any work being performed on the vehicle and given a quote for the parts and labor.
Read Full Q/A … : Bmw alternator question
I can’t find the right alternator for my Mercedes-Benz. 2003 Mercedes SL500
ANSWER : Hello – any of the MB parts sites selling a "12v, 150 amp" alternator that fits your SL500 is selling the correct specification alternator. Your cars electrical system is nominally 12 volts. The voltage regulator within the alternator allows the alternator to charge at up to 14 volts in order to bring the battery back up to at least 12 volts. While cranking for example, system voltage can drop to 10 volts or so. The difference in "system voltage vs charging voltage" is a bit confusing, but hopefully, this has helped your understanding. If not, shoot any other questions our way.
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Just changed my alternator and alternator-belt. I have periodic squeal noise. what can be the problem?
ANSWER : Hi There,
You may want to check the tension on the belt to be sure it is not loose after changing the belt. You can do this by adjusting the tensioner pulley to put more or less pressure on the belt. The squeal may also be related to the tensioer pulley itself if it is beginning to wear out or has a faulty bearing inside. I would recommend having a professional from YourMechanic come to your location to assist with this if needed.
You may want to check the tension on the belt to be sure it is not loose after changing the belt. You can do this by adjusting the tensioner pulley to put more or less pressure on the belt. The squeal may also be related to the tensioer pulley itself if it is beginning to wear out or has a faulty bearing inside. I would recommend having a professional from YourMechanic come to your location to assist with this if needed.
Read Full Q/A … : Bmw alternator question
