MAF test L/h - The Unofficial BMW M5 Messageboard (m5board.com)

The Other · 2nd July 2008, 12:19

E39 guys have been testing the condition of their maf's with this hidden OBC test "liters / hour". I was just wondering what kind of readings our M5's should display?

I tested with 2nd gear and just before rev cutter the result was 78,4 liters/h.

It would be nice to get more results to compare..

erikm54life · 2nd July 2008, 12:32

Hi,

My car idles at 2.4-3.0l/h without the a.c. on. With the a.c it does about 2.7-3.2l/h.

I don't know if this is an accurate test for determining the efficiency of the MAF though.

A lot of other issues may throw your readings beyond acceptable values...e.g. O2 sensor.

Maybe we can do a standard speed i.e. 120km/h in 5th coupled with a temp. reading ( air temp. ) at the time and see what everyone gets....though my statement above also applies to this.

At least we'll all have a standardised method of value reporting.

I'll do mine and post the figures up ASAP.

Cheers

Erik

The Other · 2nd July 2008, 15:05

Quote:

Originally Posted by erikm54life

Hi,

My car idles at 2.4-3.0l/h without the a.c. on. With the a.c it does about 2.7-3.2l/h.

I don't know if this is an accurate test for determining the efficiency of the MAF though.

A lot of other issues may throw your readings beyond acceptable values...e.g. O2 sensor.

Maybe we can do a standard speed i.e. 120km/h in 5th coupled with a temp. reading ( air temp. ) at the time and see what everyone gets....though my statement above also applies to this.

At least we'll all have a standardised method of value reporting.

I'll do mine and post the figures up ASAP.

Cheers

Erik

I got the test procedure from e39 thread, it is supposed to give best results ie. maximum consumption. Temp was 13 celsius when I tested.

Rapamaha · 3rd July 2008, 01:38

Quote:

Originally Posted by The Other

maf's with this hidden OBC test "liters / hour".

Couple of weeks ago I was able to break barely 100l/h barrier, friend of mine reached 109l/h. For the comparison E39 530iT showed 66.8kg/h (carsoft livedata), which is equivalent for appr. 90 litres per hour.

The Other · 3rd July 2008, 10:55

Quote:

Originally Posted by Rapamaha

Couple of weeks ago I was able to break barely 100l/h barrier, friend of mine reached 109l/h. For the comparison E39 530iT showed 66.8kg/h (carsoft livedata), which is equivalent for appr. 90 litres per hour.

It seems that my maf isn't up to specs...

CWY_M5 · 8th July 2008, 03:34

Mine idles at 3.4 l/h, which is wierd I think. O2 sensor is gone, so after I replace it, I'll report back on the max consumption. on my E39 M5, I can never reach the peak that everyone claims anyway....

CWY_M5 · 9th July 2008, 06:58

Anyone care to post their idle l/h?

///Manuel · 10th July 2008, 15:09

I'm idling at 1.6-1.7L/h and at full throttle 2nd and 3rd 48.6L/h.
It was 65F or 18C.

I think that's a problem and the reason my car feels sluggish.

EDIT: Disconnecting the MAF, it raised to 3.0 and then 2.0-2.2 after giving some throttle.

AlexA · 10th July 2008, 19:50

My 3.8 idles at 2.8 to 2.9 l/h at about 50m ASL. I have a fairly new O2 sensor. Ambient temperature 22C.

Alan Archer · 10th July 2008, 20:19

guys although this is a valid tool for indication

just be aware that the OBC itself has a calibration +/- constant
so readings will fluctuate from vehicle to vehicle.

I for one wouldn't replace an expensive MAF unit on the basis of an
OBC consumption reading alone.

I hope this makes sense...dont want any cases of the tail wagging the dog!

Regards,

Alan A.