3.0 P0102 Maf non running issue

[N3il123]

Hi All

I've got a 3.0 that seems to not want to play any more.

Symptoms are:

Got it out for its MOT after a long lay up, drove around fine, then on the way home slowed down to go round a junction, low revs the car wouldn't accelerate or rev, almost like the throttle cable had snapped. Minute or so later and it suddenly went again, all fine.

Took the car out a couple more times and it started to do it with more regularity.

Read the codes and its P0102 Mass or volume air flow circuit low input.

I've taken the Maf out and sprayed all the way through with contact cleaner, reassembled and now the car idles roughly and won't rev at all! (progress ... not!). I've tried disconnecting the cable and this makes no difference.

So i'm after some advice about where I go from here? I'm guessing its an electrical issue somewhere but i'd like to make sure that I have ruled out as much as possible before spending ~£200 on a new maf sensor!

Any pointers would be gratefully received!

 

[t-tony]

Tbh it sounds more like a camshaft position sensor fault. That's how my Z3 behaved when the inlet cam sensor failed.

Tony.

 

[colb]

In my experience bad Mafs dont always set a code and cleaning didn't do anything for mine had previously had a Camshaft Sensor code, that sensor was replaced which got rid of the code but the car had no power, it felt that it was holding back. Replaced the Maf with a oem one at great expence after trying a cheap ebay one without any result. The oem one worked straight out of the box, restored all the power and ran like a top. Must admit disconnecting the old maf so car ran on default settings did improve things but it was still down on power.

 

[the Nefyn cat]

Like @ t-tony up there mine did much the same when the inlet cam sensor failed. New ones are a bit on the pricey side, though, and it seems it's not worth trying the cheap ones you can find on ebay.

 

[N3il123]

Thanks everyone, i'm off on holiday tonight but will give some of these a try when I get back... I guess that the local BMW dealer is going to see quite a bit of my hard earned!

 

[t-tony]

Don't go to a dealer until we find out if a local member can help with code reading. For instance I'm near Lincoln. Where are you located?

Tony.

 

[t-tony]

@N3il123 I see you're only an hour down the A1 from me, the offer of a code read is there if you want to take me up on it. Was worthwhile for @Road warrior last week.

Tony.

 

[mrscalex]

The fact you’re quoting a generic P error code suggests you are using a generic code reader. So it’s worth getting dedicated BMW diagnostics kit on it.

It would be a surprise if the MAF wasn’t shot. I would look at getting a secondhand unit off eBay for around £20-£30. I use secondhand camshaft sensors with good success.

The part you require is 132627567451. There are no used units coming up on currently on eBay when you enter that part number unfortunately. But it’s worth a more persistent look as sellers don’t always quite part numbers. The M54 3.0 went in various BMWs at the time - 3 (E46), 5 (E39) & x5 (E53) as late as 2006.

A new one is going to be £300+.