Testing MAF

[Patrick-Irish]

Does anyone know of a way or a procedure to test the airflow meter using a multimeter ?

[Patrick-Irish]

Sorry, should have written testing "MAS" in the title !

[powers1]

I think you were right the first time
Nowadays ,I hardly test MAFs by using a multimeter but this is still the only way to do it on older cars.
The procedure of testing is always the same,you connect a pin on the MAF connector to ground(-12v).
For example on an E46 328i,to check MAF you perform 2 tests.
1.Connect PIN2 to ground with ignition on , MAF should read O Volts
2.Connect PIN2 to ground with engine idling ,full throttle briefly.MAF should read 4 Volts

Hopefully someone here can tell exactly which pins you should use on thye 4.4i.

[Isambard]

Failing the above, simply remove the connector to the MAF whilst the engine is running. If it goes lumpy or just doesn't idle as smoothly then your MAF is good. If there is no change to the idling then your MAF is bad. Also, you can try disonnecting your MAF, then starting the vehicle. If it struggles to start whilst disconnected then it is good... well, I'm sure you can see a logical pattern here, yes ?

[powers1]

I definitely do not recommend disconnecting/connecting MAF while the engine is running
If you want to disconnect MAF with engine off and then start it,make sure you have Diag equipment to clear the registered DTC which ECU will record for the MAF off

[Isambard]

Originally Posted by powers1

I definitely do not recommend disconnecting/connecting MAF while the engine is running
If you want to disconnect MAF with engine off and then start it,make sure you have Diag equipment to clear the registered DTC which ECU will record for the MAF off

You also dont recommend jump-starting either, where numerous other X5'ers, young and old-mostly with numerous years of motoring, and (from what I have seen here) vast technical experience, have categorically stated there is no problem with that, never has been and never will be. The extremely knowledgeable 'Weasel' even said it was the reason BMW put the jumping points under the hood, to which I agree with entirely, as I stated in my post that they wouldn't have put the +ve terminal in the engine bay if they didnt want you to jump their cars.

Your opinion (and more notably the only person in that thread to have said 'no' to jumping) on that was purely based on someone else's account (as you had stated in your post) and not your own experience. What experience have you had with checking MAF's? Or is this based on something you have read also?

I've done it on several cars (including a then 5 year old ('02) merc clk, which is where I got the idea from-the Merc owners forum), and there NEVER was a problem with that car (other than the detected faulty MAF I found-er...using that method!!), my X, or any others previous. Its a well known quick and easy test that every mechanic/technician I know use.

Even if it registers (what you have stated) on the ECU what negative effect can it possibly have? Or was I driving (and still am) all my cars with faults on that affected the driving, and as such every one of them needed the diag equipment to clear the 'fault'. There are high priority faults (that bring on the engine light), and there are low priority faults (that stay in the system and dont flag any light up-because its LOW priority. What you are talking about is LOW priority and will not NEED to be cleared.

If it was high priority we wouldn't need to 'wonder' if our MAF's were dead because the engine light would flag and we would be getting the diagnostic equipment out and discovering that little gem of information and putting it right. No, instead many of us drive along completely unaware that our MAF failed us a long time ago, but we are still 'wondering' if it should be driving that little bit smoother and 'wondering' if it could be our MAF's....until we do that simple test.

[powers1]

...... What you on about?
Whats a MAF?I have no experience with MAFS,or hardly any mechanical knowledge,its all just stuff I read ....I also dont own an X5.

Since you obviously been looking back at my posts,you will also find that in all of them, its all stuff I read and based on someone elses opinion and not my own experience..

After your super technical reply ,I took the liberty of looking back at your posts,expecting to find them informative and some know-how contribution!
Naaaaa......!Almost all of your posts, is you asking others to help you!

[Isambard]

Originally Posted by powers1

...... What you on about?
Whats a MAF?I have no experience with MAFS,or hardly any mechanical knowledge,its all just stuff I read ....I also dont own an X5.

Since you obviously been looking back at my posts,you will also find that in all of them, its all stuff I read and based on someone elses opinion and not my own experience..

After your super technical reply ,I took the liberty of looking back at your posts,expecting to find them informative and some know-how contribution!
Naaaaa......!Almost all of your posts, is you asking others to help you!

WOW, you really have too much time on your hands then don't you- looking back at my posts. And you are incorrect AGAIN, I didnt actually look at your posts you sad person, I just remembered your ridiculous post on the battery charging thread.

As for 'advising' people based on what you have read, and not based on your personal experience with the car, well, you have no right to do that as it is only other peoples stories . By all means, hit wikipedia or go through other peoples' posts and put down your own misguided, uninformed interpretation of their (already-diluted-down for the sake of writing a book on it) account, it doesn't mean anything-certainly not to me.

As for seeing that most of my posts are asking for advice and some are giving people advice on REAL-WORLD experience (read:not cyber-world scrawls), that is why we are here! To help eachother. What I know I happily pass on. What I dont know I hope to gain that from someone that does.

To say you 'definitely'-(who are you again, and what are your technical/mechanical credentials exactly?) don't recommend something based on what you have read and not what you have personally experienced, along with little to no technical/mechanical knowledge is shameful. Two bollocks-filled scrawls in two posts I have seen of yours so far. Top notch my friend, keep up the good work! End of.

[o. l. t.]

You also dont recommend jump-starting either, where numerous other X5'ers, young and old-mostly with numerous years of motoring, and (from what I have seen here) vast technical experience, have categorically stated there is no problem with that, never has been and never will be. The extremely knowledgeable 'Weasel' even said it was the reason BMW put the jumping points under the hood, to which I agree with entirely, as I stated in my post that they wouldn't have put the +ve terminal in the engine bay if they didnt want you to jump their cars.

Not in the middle of this or anything but.......



I read my manual the other day.

[amacman]

does this remind you of anyone