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Discussion Starter #1 (Edited)
Hi,

I have a 00 M5, with 60,700 miles. I just experienced the classical symtoms of MAF sensor failure (hesitance on hard acceleration, SES etc.) I re-read the archives and believe that it's time I replace my MAF and pre-cat O2 sensors, say $700 from Pacific BMW. :( It seems like these sensors are kinda like tires, pads, and wiper blades. I have NEVER had sensors (especially O2 sensors) failed in any of my other cars. Is this unique to our M5?

First question, should I change both MAF and O2 sensors all at once, or do them one at a time? If not together, which one first? I'm not interested to have my stealer charge me $200 per visit to disgnose these parts one by one.

Another question. Some threads seem to indicate that 00 cars have shorter MAF and O2 sensoer lives. 01 and newer evidently have no such problems (unless their mileages are still too low to have these failures manifest themselves). If I replace my MAF and O2 sensors now, would I expect to replace them again in another 60k miles (because it's an 00) or I can expect longer lives, as BMW has fixed the longivity problems once and for all since then?

Thanks.

CP
 

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$700 is waaaay too much.......

I just did this altogether and no more SES!!!

I shopped around for better prices. I spent maybe 300 bucks at bimmerzone.com on the 02s and the MAF.

Do it!
 

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Hey Chun, Can you please tell me one thing.. Does your car seem pretty normal at first from a cold start up, then gradually loose power as it gets warmer ?? Thats my problem.. I changed the MAFS and it made a drastic improvement.. But now I have this issue where as my car gets hotter or I start driving it hard, I loose power above say 5000rpm.. Sometimes it'll even go completely limp.. I was told that my camshaft sensors were the culprit but there are 4 !! I cant imagine them all being bad and I have no idea how to determine wich ones might be bad.. After reading about your o2 sensor issues I am wondering if maybe this is my problem and not the Cam sensors.. I also have a 00 M5 78k kilometers..:cheers:
 

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Re: $700 is waaaay too much.......

Can you give me the PARTS # for the MAF & 02 sensors?

Thanks!
Robert

ALEV8 said:
I just did this altogether and no more SES!!!

I shopped around for better prices. I spent maybe 300 bucks at bimmerzone.com on the 02s and the MAF.

Do it!
 

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Discussion Starter #5
atlantisvip said:
Hey Chun, Can you please tell me one thing.. Does your car seem pretty normal at first from a cold start up, then gradually loose power as it gets warmer ?? Thats my problem.. I changed the MAFS and it made a drastic improvement.. But now I have this issue where as my car gets hotter or I start driving it hard, I loose power above say 5000rpm.. Sometimes it'll even go completely limp.. I was told that my camshaft sensors were the culprit but there are 4 !! I cant imagine them all being bad and I have no idea how to determine wich ones might be bad.. After reading about your o2 sensor issues I am wondering if maybe this is my problem and not the Cam sensors.. I also have a 00 M5 78k kilometers..:cheers:
I do not drive my car hard, especially when cold, so I can't tell you if mine looses power when cold. It stays good with gradual throttle, and the SES light only comes on with aggressive WOT (rare for me). It started doing that about 2 months ago. I guess the parts deteriorate gradually.

CP
 

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It wasn't too long ago that O2 sensors were listed as maintenance items, they may still be listed for replacement around the 100k mark, but they certainly do seen to fail earlier than that on our cars. I remember in the 80's these things had a 30k mile lifespan. Some cars would have a little "sensor" light that would come on in the dash every 30k.

MAFS on the other had, really shouldn't fail, unless oiled air filters are used. Of course, mine did, as did my precat o2 sensors (according to the dealer, more below) and the dealer says the newer parts are "redesigned" and shouldnt fail, but who knows.

I question if both were bad, in my case. If the MAFS is bad, the fuel mixture will be off which could likely give a bad O2 sensor code.(mixture outside of range). If the MAFS were truely defective by design, and were upgraded, maybe that was the key problem. Dealerships don't seem to troubleshoot these things too carefully, in my experience, they throw a bunch of parts at the car for every code they find. Saves labor, and diagnostic time, i suppose, compared to replacing one part, roadtesting, checking for codes, etc. This was all done on my 00 car (6/00 prod) at about 45k miles.
Mike
 

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Discussion Starter #8
Mike,

I wish I can do what you said, but the parts on hand become an issue. Without 2 MAF and 2 O2 sensors, there's no way I can do individual replacement/testing. Once I bought all 4 sensors, it'll be much cheaper just to replace them all, then to spend the hours trouble shooting. Unless labor and time availability are both free. Definitely not so in my case. :(

CP
 

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Hi CP, what fault codes did you get? both mafs and o2? Both banks?

If there is truely a redesign of the mafs, as the dealer tells me, it makes sense to replace them both, easy and quick. Then see if you o2 fault returns. I have yet to do any of this myself, since i'm still under the cpo warranty, so i'm just speaking theoretically!
:cheers:
Mike
 

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Discussion Starter #10
Mike,

I have faults in both sensors. I thought about doing the MAFs first, and then the O2s. But then, I have to order, pay freight, take car to mechanics, etc. Everything twice. And lots of people here say the O2s fail more than the MAFs, thus I thought I'd just do them both at the same time and be done with it once and for all.

Thus my thread title: Consummables. :( Actually $700 for parts for 4 years of use is not all that bad. I paid a lot more for tires in the same time period. It's just that I have never thought of sensors as consummable items. Guess we have to adjust our thinking with the M5.

CP
 

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Discussion Starter #11
Hi,

Thanks to tip from a borad member, I re-read my warranty booklet. Evidently, the emission equipment list includes air flow sensors, emissission sensors, and catalytic converter. The warranty period is 7 years/70k miles. :thumbsup: :thumbsup:

I now have an appointment on October 23 to bring the car in for diagnoses. Hope to have these covered under warranty. I will keep you folks posted on the out come.

Keep the faith. :haha: :haha:

CP
 
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