850i Mass Airflow Sensors (MAF) for M70 Engines

[henryc]

Wondering what people are doing for replacement MAF units fitted to M70 12 cylinder engines when old units stop functioning.

I have several that are ka-put or work outside of tolerance providing too rich a mixture. Checked with Wuffer and he too has several that are not functioning as they should. I note that Bosch units from aftermarket sources seem to be no longer available (Bosch P/n's 0280212010 and 098628111) but BMW dealers seem to have them using BMW part number 13627527525, at over $1600.00 USD.
I sourced two Cardone reman units in Sept 2016 and installed them on my E31. One of the Cardone's gave up functioning properly in Jan 2020 after just 8,030 kms - about 4,990 miles.

Has anyone used the Lowe Automobile brand MAF unit - their part number 933628011. I see these on eBay for around $100.00 USD. The eBay ad says these are new; nothing about being reman.

Thanks- Henry

[petejk]

I have 2x Lowe MAFs installed, but haven’t fired the car up yet. Fingers crossed, and as for long term - fingers crossed again!


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[shogun]

Let us know when you drive the car, also compare the original Bosch with the L. On 8er org in the German language section there is a long thread, member black850i has invested a lot of time and money to make a test stand and to repair the original MAFs. His comment about aftermarket ones translated, he has tested some aftermarket ones against a original Bosch working reference MAF.
....we now come to the replicas from China or wherever they come from with different names that are labeled there, whether Ridex, Löwe, IP-Parts, Autoparts or whatever these things are called ...
I measured them on the test bench against the Bosch reference part and took a look at the externally visible details. I noticed:
• these replicas have no platinum wire
• furthermore, the cleaning and free-burning function is apparently not available
• These are not dimensionally exact either, they have a flange diameter between 69 and 69.5mm, the Bosch MAF have exactly 70mm. However, the housing looks stable and does not have the otherwise often existing burrs on the plastic as you know it from cheap products.
• Technically, the replicas are clearly out of tolerance, the 3 test parts all varied from each other (in contrast to the used Bosch parts), i.e. Too much fuel is injected, especially in the higher load range. This also explains the description of some users here in the forum that a "soot" of the engine was recognizable.
• I also noticed that the replicas when the load changes (i.e. when the accelerator pedal position is changed) tend to produce short-term signal swings (peaks) that in any case do not belong there and that none of the Bosch parts did.

To get a feel for the deviations: A brand new or factory reconditioned Bosch original air mass meter compared to a brand new or factory reconditioned Bosch part, the deviation is in a sensationally low range of approx. 15-20mV, i.e. less than 0.02V deviation.

Deviations of old / defective Bosch used parts compared to new parts as replicas
The deviations of the replicas are approx. 3 times as high as the deviation of the worst air mass meter from Ebay that I measured. At any rate, based on this knowledge, it is not possible to recommend the replicas, since it is still much better to hope for a good used part.

[petejk]

It’s great to see that someone has spent the time, and has the technical expertise to test these parts for the benefit of the community.

I have kept hold of my Bosch MAFs in the hope that I’m the future there will be a service available to recondition them back to spec.
If the Lowe units work in the interim then that’s all I can really hope for.


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[wokke]

It’s great to see that someone has spent the time, and has the technical expertise to test these parts for the benefit of the community.

I have kept hold of my Bosch MAFs in the hope that I’m the future there will be a service available to recondition them back to spec.
If the Lowe units work in the interim then that’s all I can really hope for.


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#


I've tested two different after market MAFs over the last years and results were always disappointing.
I'm now cooperating with Johannes (black850i) and I dare to say that his solution is prefect. Some MAFs are beyond repair unfortunately, but most of the ones i shipped to him came back in good working condition.
Definitley worth the expense.

[atfekete]

#


I've tested two different after market MAFs over the last years and results were always disappointing.
I'm now cooperating with Johannes (black850i) and I dare to say that his solution is prefect. Some MAFs are beyond repair unfortunately, but most of the ones i shipped to him came back in good working condition.
Definitley worth the expense.

How might one get in contact with him with regards to this rebuilding service? I have a pair of MAFs that could use a refresh.

[henryc]

This is good information - thanks, Shogun, for unearthing this information and giving the English translation!
/Henry

[black850i DE]

Hi together

the whole thread about the Bosch MAFs is here on 8er.org.

You also find information about the Bosch MAFs in this post on my new BMW E31 website. You can (auto)translate the posts on this site by clicking on your language in the top of the right corner.

Here is a picture how it looks like at the burning free process of the MAF at 1.000°C / 1.832°F:
Bosch MAF burning free.jpg

My English is not perfect, but if you have any questions I will try to answer them.

[BMSman]

Hi together

the whole thread about the Bosch MAFs is here on 8er.org.

You also find information about the Bosch MAFs in this post on my new BMW E31 website. You can (auto)translate the posts on this site by clicking on your language in the top of the right corner.

Here is a picture how it looks like at the burning free process of the MAF at 1.000°C / 1.832°F:
Bosch MAF burning free.jpg

My English is not perfect, but if you have any questions I will try to answer them.

I'm curious to know how you are evaluating the MAF's? Here's how I did it...http://www.km5tz.com/BMW%20850iP9.htm
I purchased a few used units and found them all to work very similar. Concluded they are quite rugged and last a long time.

[henryc]

Hello, Johannes - I read your MAF report from your website and found it very interesting. Same with the report/link from BMSman.
Do I understand correctly- based on the comment from Wokke- that you can repair MAF units from our 850's? If so, what is the cost for this service? I live in Vancouver Canada and can ship several units to you for testing and repair.
Thanks! Henry

[shogun]

The problem will be international shipping/customs clearance. For example when you ship some units to him in Germany from Canada, in worst case he has to take a day off from work to drive to the customs office in charge to clear the units out of customs, has to pay import duty and 19% VAT, even if they will be repaired and returned/re-exported to Canada. German customs office is very strict. Example:
Some years ago I sent a part to a friend in Germany, that part was defective and he just wanted to have it as sample. I declared it as defective parts, worth less than $20, but they did not believe that and kept the part in customs and they sent him a postcard to visit them. That customs office was 30 miles away from his home, so he took a day off from work and visited that office. He explained the whole story to them, they did not believe it, then he said, it is for a older car, ahhh, for an oldtimer, then it is probably much more worth than declared by the sender. If you cannot provide a valid invoice, we will ask an expert to evaluate it etc pp., so he refused to receive it and they sent it back by sea and I got it 2 months later.

[black850i DE]

Here's how I did it... http://www.km5tz.com/BMW%20850iP9.htm
I purchased a few used units and found them all to work very similar.

I know your posts and your website, this is great work, also your other E31 projects, very very cool!

But you made your tests - used part against used part, the measurement should be against a new part only, it has to come directly from the factory, not used at all.
Also there is an electronic component missing in your test build that the ECU module (DME) would support while operating in the car with running motor.

Hello, Johannes - I read your MAF report from your website and found it very interesting. Same with the report/link from BMSman.
Do I understand correctly- based on the comment from Wokke- that you can repair MAF units from our 850's? If so, what is the cost for this service? I live in Vancouver Canada and can ship several units to you for testing and repair.
Thanks! Henry

Hello Henry,
there are some points where the MAF's are wearing out, one point is the platin wire, carbon from the oil mist burns on it, but there are also other points. If someone knows the places, he can recognize them.

As Wolf (Wokke) wrote already, he is cooperating with me, he makes the international transactions regarding the MAFs. So if you need more information please contact Wokke: info@wokke.de

So, to the re-manufacturing, there is a limit, it is possible to repair MAFs with my method up to a deviation of 230% outside the Bosch tolerance.
It would also be possible to correct more deviation but it would not make sense tor repair a MAF with more deviation, because it is not stable anymore.

But also for such cases (over 230%) you can get re-manufactured and tested exchange MAF's from Wokke, also you will get back your defective MAF, so all this process is clear and transparent.


The following types of MAF's can be tested and repaired:

1.) M70 / M50:
Bosch: 0280212025, 0986280130, 0986280111, 0280212010
BMW: 13621718521, 13621733678, 13627527525

Fits in Cars / motors:
- 320i (E36) / M50 motor
- 520i (E34) / M50 motor
- 750i,iL (E32) / M70 motor
- 850i,CI (E31) / M70 motor


2.) S70 / CSI:
Bosch: 0280212026
BMW: 13621316166, 13621316167


3.) M73:
Bosch 0280217110
BMW: 13621736224

Fits in Cars / motors:
BMW E31 850i / M73 motor
BMW E38 750i / M73 motor


To the ratio of the defective MAF's I have tested:
Every MAF I have tested gets a label with a number and I put all measured data in a register, values before and after the re-manufacturing are noted.

So the ratio until now is 57% of my tested MAF's are outside the tolerance, that means, statistically every V12 M70 runs with at least 1 defective MAF.
Also interesting what many people don't know, the synchronisation of the 2 throttles (DK) is made by the values of the MAF's, so if one or more of them is defective all this internal regulation procedure no longer works correctly.

I will add to that in the next few days 2 more chapters to my report on the website:
- What are the causes of air mass meter wear?
- Why is a defective air mass meter often difficult to recognize?

[wokke]

The problem will be international shipping/customs clearance. For example when you ship some units to him in Germany from Canada, in worst case he has to take a day off from work to drive to the customs office in charge to clear the units out of customs, has to pay import duty and 19% VAT, even if they will be repaired and returned/re-exported to Canada. German customs office is very strict. Example:
Some years ago I sent a part to a friend in Germany, that part was defective and he just wanted to have it as sample. I declared it as defective parts, worth less than $20, but they did not believe that and kept the part in customs and they sent him a postcard to visit them. That customs office was 30 miles away from his home, so he took a day off from work and visited that office. He explained the whole story to them, they did not believe it, then he said, it is for a older car, ahhh, for an oldtimer, then it is probably much more worth than declared by the sender. If you cannot provide a valid invoice, we will ask an expert to evaluate it etc pp., so he refused to receive it and they sent it back by sea and I got it 2 months later.

Yes, German custom officers can be real bitchy.
This is one reason why Johannes cooperates with me when it comes to international business. I have to deal with customs on a regular basis and they already know me and what I am doing.
I also have the so called EORI number which a private party doesn't have making things a lot easier.
So if anyone from out of Germany has a MAF issue please contact me at info@wokke.de (email ONLY !!!! no PM or other messaging services please) and we go from there. Johannes will be the one to take care of the job while I'm in charge of the logistics.

On a side note: 19% VAT is charged on any import from outside the EU (plus extra import duties eventually) and a private party can't claim this money back. I'm running a business with a German VAT ID number and I can claim the VAT back from the German authorities and DO NOT have to charge it back to my customers as long as the shipping address is outside of the EU.

[black850i DE]

Hi
I added the 2 new chapters to the MAF report on my website.

[BMSman]

I know your posts and your website, this is great work, also your other E31 projects, very very cool!

But you made your tests - used part against used part, the measurement should be against a new part only, it has to come directly from the factory, not used at all.
Also there is an electronic component missing in your test build that the ECU module (DME) would support while operating in the car with running motor.

Black850i DE,
Unfortunately I did not have a new unused MAF reference unit... the Bosch refurb was the newest. I tested 6 units in total.

Please tell me what is the electronic component I am missing and how does this affect the results?