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Discussion Starter #1
I have my car in the shop for an engine light issue and they discovered that two of the four oxygen sesors have gone bad. The cost to replace is about $520! Is this an issue you have experienced?

I also need to get a servo replaced that locks the fuel cover in place when the car is locked. It is bad and is causing blown fuses, thus not allowing my remote controls to function. $197 thank you grrrrrrr

The good news was that my rear view mirror was beginning to fail. The night mode was not completely darkening the entire mirror. I am out of warranty by two weeks. BMW decided to replace the mirror for free. :thumbsup:

Besides having to replace the windshield for $478 that would be the total at this point. I can see that the electronics is going to continue to be a real failure issue over time with this car.

Mark
 

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Re: Oxygen Sensors etc

Mark,

How many miles do you have on the car?

I've had to replace my pre-cat O2 sensors twice. Once at 35k miles, and once again at about 65k. I'm at 91k now, so I'm just counting the days til it happens again.

I used to drive the car at track days, and that probably aged them a little prematurely.
 

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Re: Oxygen Sensors etc

I got a SES light recently, so I took it in to the dealer. They said it was the O2 sensors and replaced them, but luckily it is still under warranty. :)
 

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Re: Oxygen Sensors etc

Just wondering? But cant you just buy O2 sensors at places like auto zone and just get under the car and take the old ones out and put new ones in? Just curious thought this might be an easy job, Josh
 

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Re: Oxygen Sensors etc

You can get them at auto stores but don't get the universal ones.
Spend the $145.00 and buy the pre made from Bosch.
I was told that the universals don't have the same resistance and might set the light off again. I this has happened to any I'd like to hear about it.
I've been told you should change the fronts before 60,000 if you haven't.
 

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Re: Oxygen Sensors etc

I have 48,000 miles on the car. I do not know which two sensors failed, but two of the four did. If you can get them for $150 or less a piece then that is a good deal.

Anyone know how hard they are to replace?

I don't want to hear about your car being under warranty. Lucky people.

Now, how many have had issues with the rear view mirror?

Mark
 

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Re: Oxygen Sensors etc

Replacing the O2 sensor is a breeze.

You'll need to jack the car up to get underneath, and it's about a half-hour job.

Unscrew O2 sensor from pipe.
Unplug the wiring connector.
Plug in new wiring connector.
Screw in the new O2 sensor, and torque to spec. (sorry, don't have the spec here in front of me)

Repeat for other side.


As for the mirrors, I haven't had any problems there. (knock on wood!)
 

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Re: Oxygen Sensors etc

I agree with Louv. It is easy. Just want to add this:

1. You must apply Never-Seize or something similair, or you have performed the very last O2 sensor replacement on that exhaust...

2. Apply the Never-Seize _only_ to the threads.

3. Torque to 50 (yes, fifty) Nm using a crow-foot and a torque-wrench.

4. You must not get grease or underbody stuff or anything on the visible part of the sensor or where the cables enter it. (The sensor works by the difference in oxygene concentration in the air and in the exhausts. It litterally must be allowed to breave freely, or it won´t work correctly.)

5. Sometimes you get O2 sensor errors beacuse of marginal MAFs, so I´d check the MAFs first.

David

Added October 14th, 2006:

The pre-cat O2 sensors sold by BMW now has anti seize stuff on the threads, so you only need the O2 sensors and the tools. Very practical.

David
 

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Re: Oxygen Sensors etc

DavidS said:
I agree with Louv. It is easy. Just want to add this:

1. You must apply Never-Seize or something similair, or you have performed the very last O2 sensor replacement on that exhaust...

2. Apply the Never-Seize _only_ to the threads.

3. Torque to 50 (yes, fifty) Nm using a crow-foot and a torque-wrench.

4. You must not get grease or underbody stuff or anything on the visible part of the sensor or where the cables enter it. (The sensor works by the difference in oxygene concentration in the air and in the exhausts. It litterally must be allowed to breave freely, or it won´t work correctly.)

5. Sometimes you get O2 sensor errors beacuse of marginal MAFs, so I´d check the MAFs first.

David
I agree with the anti sieze, the stuff works great
 

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Re: Oxygen Sensors etc

Great info, but the dealer has done the first two, so I now need to be aware of the other two.

Thanks,

Mark
 

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Re: Oxygen Sensors etc

I purchased a 2000 M5 with 60,000 with no records of the service history. The car now has 115,000 miles. How can I tell if the O2 sensors need to be replaced? What are the fault codes?
 

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Re: Oxygen Sensors etc

louv said:
...I used to drive the car at track days, and that probably aged them a little prematurely.
Getting them good and hot might actually increase their life, or at the least, it can wake up a sluggish O2 sensor.
 

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Re: Oxygen Sensors etc

Nix930 said:
I purchased a 2000 M5 with 60,000 with no records of the service history. The car now has 115,000 miles. How can I tell if the O2 sensors need to be replaced? What are the fault codes?
Perform a MAF / fuel-flow test. If that gives good numbers, the O2 sensors and everything else involved in the air/fuel mixture control is probably doing fine.

See:
http://www.m5board.com/vbulletin/showthread.php?t=54788

David
 

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louv said:
How many miles do you have on the car?

I've had to replace my pre-cat O2 sensors twice. Once at 35k miles, and once again at about 65k. I'm at 91k now, so I'm just counting the days til it happens again.

I used to drive the car at track days, and that probably aged them a little prematurely.
How did you know your Oxygen sensors were bad? Did you have SES lights turn

on?
 

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Blue Thunder said:
Quote:
Originally Posted by M5BOSS
Check this, they are at $75.43 each.

http://oem.overnightautoparts.com/pa...gory=C&dp=true


There are 2 types of sensors listed on this page. Is it ok to use the cheaper one? What is the difference between the two?

Also, do they only work in front of the cat or can I use them for the post cat position also?
I just received my O2 sensors today ($75.43 each) and they are OEM original BOSCH part#13477 . There are two different packages after and

before the CATs. The ones that need maintenance are before the CATs.

http://www.boschusa.com/AutoParts/OxygenSensors/PremiumOxygenSensors/

http://replacement.autopartswarehouse.com/parts/autopartswarehouse/wizard.jsp?year=2000&make=BM&model=M5--003&category=All&part=Oxygen Sensor&dp=true
 

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Great info here about the o2 sensors...


thx Mah
 
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