MAF sensor advise (Non Renault Content Sorry)

[J8TRO]

Sorry guys, this isn't Renault based, but need some advise

My girlfriend has a MY07 Mini Cooper, it went for its MOT last week and failed on emissions, my local mechanic is a real sound guy, but all his diagnostics kit found was "MAF sensor plausibility". His diagnostics kit cant delve further.

Now simple thing is, change the MAF sensor, but its nearly £200, I don't want to spend that to find its not the issue.

To add a little more info, the car was serviced at the same time as the MOT, due to it being a little hesitant just over 2k revs. Its had oil, filter, air filter and new plugs and the hesitancy is still there.

It all seams to add up, just wanted your opinions.

To get it plugged in at Mini would cost £90 alone

[Guybrush]

Had a similar kind of issue with my Octy.
Called the RAC, guy came out to diagnose/fix issue as per normal. He thought it was the map sensor. He drove down to ECP, picked one up, tested it, discovered it wasn't the problem, then returned the sensor.
I didn't part with a penny
(Problem turned out to be a small split in one of the hoses.)

[Brigsy]

Just pull the probe out of the exhaust and purge until it passes? Ive never had a car fail on emissions lol.

Might be worth seeing if any independant diagnostic lads have the software locally.

[J8TRO]

that's a good call on the RAC / AA as i'm a member.

Plan at the minute is to clean the MAF first and see if it makes any improvements to the hesitancy. I'll see how it goes.

[Sparkie]

or you can drive to my house - 9 mins away.
i can plug it in and see what the problem is on my machine...
what kit did your diag guy use?

[J8TRO]

Hi Sparkie,

Thanks for the offer, I might take you up on that pending my findings.

I've been / and still are being massively confused by BMW. Striped down the inlet on the car the weekend and found no obvious location for the MAF sensor, instead found the MAP sensor, took that out, cleaned it and it did nothing. After calling mini, I asked the location of the MAF, the parts guy told me it didn't have one.

Looking on the internet and speaking to ECP, there is one, in fact the ECP guy told me there was no MAP sensor!

I know you work at GSF, care to shed any light for me?.................... pretty please

Oh and I' not sure of the equipment used, but the code was "2B68 Air Mass Flow Plausibility".

im now thinking it might be something silly like a split hose and someone else has suggested the EGR valve. Think I might have to bite the bullet and get BMW to diagnose it....................that will piss me off!

[Fordy]

Check all the intake for leaks

[Andy M]

What's the exact model and year of the car? May be able to find clarity on the real oem parts fiche site.

[J8TRO]

What's the exact model and year of the car? May be able to find clarity on the real oem parts fiche site.

Car is a Mini Cooper R56 hatch, reg YT57 XWE 1.6 petrol

Any easy way for checking leaks, my mechanic said he had a good look and found no leaks.

[J8TRO]

Thanks for the heads up on that site, its great.

Just had a quick look

http://www.realoem.com/bmw/showparts...52&hg=11&fg=40

The item marked as "9" is the MAP sensor as I know it, described on the site as "differential pressure sensor"

[R5MJH]

what was the odb2 code mate i can check AUTODATA and see what it comes up with,

autodata is a great literature tool

[J8TRO]

The only code I have is the one above, "2B68 Air Mass Flow Plausibility"

[R5MJH]

ive just checked that and its not in the odb2 database so not sure what he used the odb2 is the easiest system, cant you borrow a odb2 scanner or buy one on ebay there £20, autodata just got my missus seicento back up and running correct and i was on the fiat forum and they didnt even get it right mate, easy to use too

[Andy M]

It's a helpful site, can't trust pricing though as I don't think it's updated much (and obviously in $) I used to use it for parts on my old bike. I'm no BMW expert however and never laid eyes on a BMW mini engine before!!

You'd expect a mass air flow on the air box as normal. Under fuel perpetration systems they look to list 2 types or air box, one with a mass air flow and one without. The HFM one is the one with it.

http://www.realoem.com/bmw/showparts...00&hg=13&fg=20

HFM - hot-film air mass meter.

[J8TRO]

I confident now after all my research that there is no MAF sensor, only the MAP. The diagram in your link it not like the intake on the car, its like the one below.

http://www.realoem.com/bmw/showparts...99&hg=13&fg=20

Hence when I stripped it down on Saturday morning I was looking for a part like the one in your link and was surprised when I didn't find it. Got knows why it has the two different set up's I presume one is American or some other country.

[J8TRO]

I didn't realise the OBD2 port readers were so cheap. I must invest. any you could recommend or to avoid?

[R5MJH]

tbh mate they all do the job well

this is the one i used on my car

http://www.ebay.co.uk/itm/Car-fault-...ht_3222wt_1167


over 6000 sold lol, get one and read code then i can use autodata to see what they recommend doing

[J8TRO]

I'll order the part and the reader, i'm up against it now, as the retest for the MOT runs out Saturday, I don't want to order the reader and then run out of time getting the part.

Thanks for the advise mind

[R5MJH]

the readers worth having as they work on most new cars and @ £20 its a must boss

[J8TRO]

Oh just to add some info, the car never gave an engine warning light, the code found, was the only one when my mechanic looked out of curiosity.

[R5MJH]

sometimes theres not a light on but codes can still be read boss

[Andy M]

At a guess, the difference in air boxes and MAF or no MAF may be just be down to blown vs n/a engines with different ECU set ups.

It still may not be that sensor mind, it could just be a leak in the inlet as suggested. Check all the vac hoses closely if you can't pressure test it with an air line.

Could also be electrical on the loom (bad earth, broken sensor wire) although you'd expect it to throw a code and light the CEL if it was that sort of issue.

I'd personally want a second scan to verify before you go spending any moolah on parts. It may be worth trying to get it to Sparky, clear the ECU of any DTCs and retest after a quick drive (Italian tune up style!)

Has the car been thirsty recently?

[J8TRO]

I don't really drive the car, but my girlfriend (who does have a clue about cars thank god) said it isn't using more fuel than usual. Not noticeable amounts anyway.

Ive bought a OBD2 reader for myself and ordered the part anyway. Ill check the codes etc before fitting it as a precaution and ill be giving a thorough check for leaks. Ill update with how I get on after bits have arrived.

Thanks all for the advise

[Sparkie]

when you need live data and a guide to what Bosch think is wrong, then give me a shout.
an OBD2 reader will only look at engine emission related problems, which thankfully a MAF is..... but the cheap readers dont tend to have live data.

- it's part of my job to sell, set up and fix the problems on diagnostics machines.

[J8TRO]

Oh my days, this is getting to me now. ODB11 reader can find no information, no faults, no emissions issues. obviously only a cheap bit of kit but zilch!

Changed the MAP sensor anyway as it came in the post and was only £40. It hasn't cured the hesitancy issue so think that's not going to help.

Going to the MOT centre tomorrow to check emissions anyway, just in case.

Phoned BMW as a precaution to get them to diagnose on Saturday morning. Guess what.............they don't do it at weekends, I have to take it in on a week day.

Sparkie............I may need your help. You about tomorrow?

[Sparkie]

im about today and tomorrow.
paternity leave you see.....
i'll text you in a bit, provided your contact details on here are still OK.

[J8TRO]

Just wanted to close this one out.

Firstly, Thanks for the offer Sparkie , unfortunately my contact details have changed (now updated) and i saw the response to the tread too late.

Basically the car went into Mini (BMW) for diagnostics as we were running out of time and the MOT had lapsed, and my girlfriend was getting quite stressed out about it all and given its a BMW i thought they would know best.

BMW were a total waste of time, they suggested changing the Lambda sensors (both of them) at a cost of £420.00 just for the parts. When i asked if this would solve the issue they said they "think so, but couldn't be sure", if it didnt i needed to put a whole new exhaust/cat on it at over £800...........

Even based on me buying savvy and fitting myself, i wasnt happy to do that, as it was surely masking a bigger issue. I managed to talk directly to the BMW tech guy who was the only helpful person there. From the information we could bounce between us, we tracked it to an internal issue in the engine (possible piston rings), and the excessive oil usage through the engine had taken its toll on the Lambdas and CAT. Changing them would be pointless in the long run. Trying to find the internal issue would have cost far too much. His advise was to get rid. We have ended up chopping it in for £1000 under book price just to get rid. Its very annoying, just better out of the situation than under pressure to spend silly money on a car only worth around £5k.

[Trevhib]

Sorry to hear this. Modern cars, what a pain in the butt

I had a 1 owner, 3 cylinder Corsa on a 1999 V plate. It had been driven/looked after really well and I was buying it to have a good stab at cheap motoring.

Well, within a few months it had developed a power loss/hesitancy issue and then it started cutting out randomly (and not restarting). No engine warning lights.

Turns out these crappy little things have the full range of electronic sensors and control boxes as top of the range family cars. I spent ages researching and switching out this sensor and that part and testing over and over. In the end, like you, I had to chop it in for half what I paid for it (in a very painful and drawn out process), and I ended up with a BMW that at the time I didn't realise was a CAT C. Fantastic.

That Corsa was the second time I'd tried to really cut down on motoring costs. The first time I bought a Pug 205 diesel from the auctions. That was a total disaster too.

[J8TRO]

Trev,

They advised that the car would go into a car pool or auction and thats all they could offer us to take the car off our hands. I'm just curious as to if it will end up on their forecourt or dealer network, as i know to them they could market the car around £7k all day long.

Annoyed doesn't quite express my true feelings about it.

Besides a little bit of hesitancy (and I mean a tiny bit) the car was in A1 condition. I know my 5 probably kicks out 10 x the omissions!

[Trevhib]

Yeah, they are the winners.