Help needed with a BMW 3 Series

[fat controller]

I'm in need of the opinions of those with more knowledge than I, please.

My father in law has a BMW 3 Series, 2.8 litre 6-cyl on a P-reg (so '96/'97 if I remember correctly?); its a tidy wee car, however recently it has started to run a bit rough, particularly when accelerating.

A friend of mine (mechanic) looked at it briefly, and discovered that the spark plugs were the wrong ones for that engine, so renewed them and could find nothing else obviously wrong. In the weeks since however, it has gotten progressively worse, is now running like a bag of spanners most of the time, and is going through petrol so quickly that my father in law is now a shareholder in BP

Now, on top of all this, father in law has had a bit of rough luck in his personal life, and is struggling financially, so much so he is reluctant to hand it back to my friend (or anyone else for that matter) to investigate further as he doesn't have the funding to pay for very much.

This car is a bit of a lifeline for him, as his ex. missus moved a long way off, and he needs it to be able to see his young son, so skint as I am, I would really like to help.

I had a cursory look at the car, and whilst poking around I noticed that the MAF sensor is held in at one end by a plastic cable tie - having had a MAF fail on my old Merc, I know that it caused rough running, lack of power and a raging thirst - therefore, I suspect that it could be the MAF; does this sound like a reasonable bet?

Also, if it is the MAF (or if its worth a shot at least), is there any difference between a pattern part and a genuine part (considering the age of the car, and the fact that I am likely to be paying for it too)?

Advice and opinions please ladies and gents?

[Bratty]

Try unplugging the MAF and see if there is any difference in how it runs, could be a split intake boot. Have an ask down the pub if anyone has a code reader (or INPA Program) that can tell you if a sensor is malfunctioning.

Were all 6 spark plugs (that were removed) electrodes all the same colour ie. very light brown?

Dunk

[fat controller]

Father in law tells me he ran it with the MAF unplugged, and it was just as bad; the only thing I can try is to take the old MAF off, and clean douse it with some electrical cleaner and see if that makes any difference (even if only for a short time).

I don't know what colour the plugs were that came out, although I am not short of whipping them out again and having a look at them. I'll ask about at work to see if I can get hands on a code reader - I take it that its one of the OBD II type?

[Bratty]

Yep pretty sure its OBD II, you can get a cheap code reader that just throws out codes and it is very easy to decifer them on the internet.

MAF sensors are B. Expensive 200 poundsísh!!?!! so be careful cleaning it (NO Q-TIPS) here is a cheap place that I have found http://www.mafsensorstore.com/de/bmw...528i-728i.html but cannot say if they are any good or not!

Think the key is getting the codes cleared, run the car again and get the fresh codes decifered and go from there!

Good Luck

Dunk

[fat controller]

Thanks

Father in law brought the car round this afternoon, running like a pig. I disconnected the MAF, and we took it for a run, and it ran absolutely fine - turns out, he hadn't disconnected the electrical connector, but had simply took the intake end of the MAF out of the pipe coming from the airbox and left it in free air.

MAF ordered from Eurocarparts, for just over £100 after their 25% discount, which should arrive through the week. I'll fit it for him next weekend, and I think the job is a good one

If only I could sort my own motoring dilemmas so easily!

Cheers