XSeries-forum

Hi guys

Hope everyone is enjoying the weather, I was scouting about my engine bay today to see what it entails to change the stat for a new one and recently I have had a couple of flat spots with the car on pulling away and changing gear! So I was looking around for any general split hoses and the like, I decided to have a look at the MAF connections to make sure they were clean, I disconnected it and thought a good way to check would be to drive with it unplugged a few miles, to my surprise it's like having a brand new car, the power is amazing, no flats spots at all, gets to higher speeds in lower gears and seems smoother and more eager! The only thing I noticed was that I could hear the turbo spool up more noticeably, only with the window down though, with the window up could barely hear it at all with stereo off etc, is that normal? Also would driving with the MAF unplugged have any consequences until I source a new one? Also I have no engine lights or warnings on the dash with it unplugged, again is this normal or will the show up as the miles go on?

Cheers

Ollie

I am really surprised you noticed it was better with the MAF unplugged, this should have bought a fault code up.

maf defaults to a manufacturer default when open circuit etc.  No fault code initially I think.


Sent from my iPhone

Yeah I was surprised myself, so I assume that means the MAF is duff? It looks to be the original item. I will have to keep an eye to see if any warning lights come on but just assumed it would run on a default map if the car was not getting info from a sensor

Ollie

If you buy a new maf get a genuine part not one of the shite ebay copies

Thanks Shadrack

Do you know if BMW do an exchange thing with a new MAF? When I had the Audi they seem to like ruining the MAFs so the do an exchange and you get money off the new one

Ollie

PM Cotswlod BMW on here and ask them..

You never know??!

Seeing as you're running ok without the maf connected, have you tried cleaning it, they do get covered with shite due to all the air coming in.
Try a cotton bud and some electrical cleaning solvent, usually you'll find the sensor tucked up inside, you never know, might save you a few bob.

......and be very gentle!

Carb cleaner is supposed to be a good solvent as it cleans the oil/fuel deposits off.

[quote="Olliefrom83"]
Yeah I was surprised myself, so I assume that means the MAF is duff? It looks to be the original item. I will have to keep an eye to see if any warning lights come on but just assumed it would run on a default map if the car was not getting info from a sensor

Ollie
[/quote]
It could still be a leaky intake hose, this has been quoted before, as the MAF can't see all the aie that's being drawn into the engine if more air is being sucked in after it, happened a few times before, more so on the 3.0i if I remember rightly, as said the car will be running on a default setting so it won't use the MAF info. If more air is getting in than the MAF can see you will be running very lean.

Cheers guys, appreciate all the info, do you think that is why the turbo sounds louder? Could an air leak make the car run more potent without the MAF? I will try cleaning it as described, but the car is not down on any power (from what I can tell) with it plugged in or unplugged, it just seems smoother and more responsive without it plugged in and also eliminates a few flat spots I was having like the car was holding back

Cheers Ollie

I have heard of a whoosh sound on acceleration that was caused by a cracked inlet manifold. Could you be mistaking this for the turbo ? It's common to be able to hear the turbo whistling with the window down.
I even heard of people spraying the intake hoses with easy start as of the engine is sucking in air it will sick in the easy start and alter the tick over rate.
Dificult one you have there as if you buy a new MAF and it's still the same you have wasted some money, but if you take it to a garage that will cost in labour as well. >:( 

Question...

Would an induction leak .... or a faulty MAF sensor also cause a 3.0d Diesel to Pink ??
as Im sure I can hear my D-Sport pinking... in addition to the normal Diesel knock noises ??

I've got no flat spots or power problems, but the pinking is definitely there & I'm sure I have a induction pipe leak under the front of the vehicle some place...