so, you disconnect your MAF and the car runs "better"...

[Sir Montalbon]

please shoot me if this is beyond a stupid question. though if you're feeling it, i will gladly accept enlightenment...

installed some euro smileys this weekend (thanks seventhstoned) which, along the way, requierd me to remove my air filter/MAF/intake hose etc to reach some of the more stubborn screws. afterwards, the car ran like shit.

i've already been experiencing a rough idle and the occasional smoke out the tail pipe (burnt oil smoke as far as i can tell) along with a CEL throwing 1213 (secondary o2 rich/lean condition according to Bentley), but this was more of a choking of the car. like, i could floor it in nuertral and the car would barely rise above idle, then suddenly shoot up in rpm's, as if someone suddenly un-choked it. (bad MAF? clogged cats? Axl Foley banana in the tailpipe?)

i disassembled the air filter/MAF/boot assembly again and put it back together making sure everything was snug. no change. then i disconnected the MAF, and everthing smoothed out signifigantly, although the car still idled a little rough.

i'm still learning about the air intake, MAF, and the other assorted intake functions, so hopefully i'm not asking something either a) incredibly stupid, or b) incredibly vague. just hoping someone could either chime in regarding a similar experience, or maybe give me an outline of the things i would need to investigate/eliminate to eventually lead me towards a solution.

TIA

[m60b30530i]

well clean out your maf with MAF cleaner found at pretty much any auto parts store. The MAF can die it happens. i would warm the car up rev it a little and with a laser temp reader point it at both cats if one is hotter than the other or even looks red then its time to replace them.

[535ipower]

well clean out your maf with MAF cleaner found at pretty much any auto parts store. The MAF can die it happens. i would warm the car up rev it a little and with a laser temp reader point it at both cats if one is hotter than the other or even looks red then its time to replace them.

Or touch the pipe before the cats a little if you don't have a laser pointer temperature thingy. One will be way way hotter than the other just be careful as it will be really hot. Also look for someone local and ask them if you could use their maf for like 20mins

[Grim Reaper]

Make sure all your sensors you disconnected got reconnected properly. One is probably left unplugged or isn't fully seated.

If the car was running well before disassembly, most likely something didn't get put back together correctly.

[Sir Montalbon]

well clean out your maf with MAF cleaner found at pretty much any auto parts store. The MAF can die it happens. i would warm the car up rev it a little and with a laser temp reader point it at both cats if one is hotter than the other or even looks red then its time to replace them.

Or touch the pipe before the cats a little if you don't have a laser pointer temperature thingy. One will be way way hotter than the other just be careful as it will be really hot. Also look for someone local and ask them if you could use their maf for like 20mins

thanks for the suggestions. i'll look into this.

Make sure all your sensors you disconnected got reconnected properly. One is probably left unplugged or isn't fully seated.

If the car was running well before disassembly, most likely something didn't get put back together correctly.

doubled checked, and everything looks well seated. i will give it the obligatory triple check though.

as for the car running "well" before disassembly (a little clarification)... before installing the new lights, the car was idling rough and a bit hesitant to accelerate whether cold or fully warm. usually blew some smoke upon initial start up, and would blow a little smokescreen if i got stuck at a 3-4min traffic light while the car was idling rough, but once under way, it ran fine.

after the install, all hell broke loose. hope this is a little clearer.

[bubba966]

Car idling better with MAF unplugged is a sure sign of a bad MAF. Don't run it unplugged for long periods of time though. Just do it to test your MAF.

Not sure about the B30 MAF, but the best price I found on a new M60B40 MAF was from autohausaz.com

[StealthBimmer]

Car idling better with MAF unplugged is a sure sign of a bad MAF. Don't run it unplugged for long periods of time though. Just do it to test your MAF.

+1 , exactly. If it runs better when unplugged, then it is not reading correctly. Could be dirty, or shot.

[skylinergtr]

probably a bad maf, spray some intake cleaner if you have some around to see if cleaning it will make it work. Otherwise dont waste your money buying a maf cleaner to find out that its dead. When my maf died i picked up a used one from a 540i on ebay for $50. Also otherthings like o2 sensors, or the pcv plate can cause the car to run like shit. Check for vacuum leaks too since you took out and put back the the intake. Also are you getting a check engine light? can you find the codes? Best of luck...

[Sir Montalbon]

got some MAF cleaner and got the MAF housing off the car.

now then, how would one go about removing the screws seen below? i've never seen ones like these. looks like they're meant to only go on, not come off.

[janders211]

hit it with a dremel cutting blade (aka, just enough to cut a line into it so you can take it off with a flat head screw driver).

[T444E]

hit it with a dremel cutting blade (aka, just enough to cut a line into it so you can take it off with a flat head screw driver).

This.

I just replaced my MAF the other day; 300$ I did not want to spend

My old E30 would run better when I unplugged the AFM; swapped another AFM and acted the same. Ended up being the ECU.

[janders211]

FWIW - a bad MAF will have the same symptoms, as a air leak after the MAF.....best bet, as mentioned before is try a spare MAF

[Sir Montalbon]

janders, garret... the dremmel trick worked like a charm, thanks.

going to clean the shit out of it and see what happens. if no improvement, i'll see if i can source a loaner or a good used one. have a feeling i'll end up going this route though:

http://www.directauto.com/product-ex...Air_Flow_Meter

comes with a $66 core charge. whatchu fellars think?




***EDIT: Automerge! WTF... how do you get around that?***

test drive results are in.

plugged in the MAF and cranked her up. no CEL!!! yeah! ....SIKE.

no CEL, but the car still ran like crap and wouldn't acclerate. unplugged the MAF and car ran much better again, but got the CEL back. stomp test shows 1213 (secondary o2 lean/rich condition, same as before). plugged the MAF back in and the CEL stayed on, even after restarting the car. stomp test again and same ol' 1213.

so... about that reman MAF... lol...

[T444E]

janders, garret... the dremmel trick worked like a charm, thanks.

going to clean the shit out of it and see what happens. if no improvement, i'll see if i can source a loaner or a good used one. have a feeling i'll end up going this route though:

http://www.directauto.com/product-ex...Air_Flow_Meter

comes with a $66 core charge. whatchu fellars think?




***EDIT: Automerge! WTF... how do you get around that?***

test drive results are in.

plugged in the MAF and cranked her up. no CEL!!! yeah! ....SIKE.

no CEL, but the car still ran like crap and wouldn't acclerate. unplugged the MAF and car ran much better again, but got the CEL back. stomp test shows 1213 (secondary o2 lean/rich condition, same as before). plugged the MAF back in and the CEL stayed on, even after restarting the car. stomp test again and same ol' 1213.

so... about that reman MAF... lol...

What you linked to comes up as "
1993 BMW 325i # 13621747155 - 280217502 2.5L M20 VIN Air Flow Meter"

Which is totally wrong.
If I were you I would go to Autozone, get one, try it and see if it makes it better. If it does, wahoo. Return it and find it cheaper. If it doesn't, return it and keep looking for issued.

[skylinergtr]

take a look at your o2 sensors. undo and inspect both of them. If they are covered really black they are probably bad, or atleast one is. When my car was running like crap i replaced the maf (used one) and bought two new bosch o2 sensors. Even after replacing the maf the o2 sensors were causing the car to still run like crap. You will probably get advice on that the o2 sensor codes are just acting because the maf is bad or unplugged, but most likely the o2 sensors need to be replaced. I spend under $300 in parts.

[Sir Montalbon]

What you linked to comes up as "
1993 BMW 325i # 13621747155 - 280217502 2.5L M20 VIN Air Flow Meter"

Which is totally wrong.

i thought this too, but ran a check in realoem and got:
Part 13621747155 (Hot-film air mass meter) was found on the following vehicles:


E34: Details on E34
E34 525i Sedan
E34 525i Touring
E34 530i Sedan
E34 530i Touring
E36: Details on E36
E36 325i Sedan
E36 325i Convertible
E36 325is Coupe
E36 M3 Coupe

take a look at your o2 sensors.

this has crossed my mind as well


upon more general MAF research (non-e34 specific), i ran across mutliple mentions of a vaccum leak being the cause for a car running better with its MAF disconnected, similar to what janders mentioned.

upone more investigation around my engine bay, i did notice a very pronounced "whooshing" or "sucking" sound when i throttled the engine. what i would like to do is replace my plugs, valve cover gaskets, intake gaskets, and valley pan gaskets, if for no other reason than the learning experience and peace of mind. this will cost $$$

and herein lies my dilemma...

it's not so much the cost as it is the ultimate plan. i bought the car with all intentions of a b40/6spd swap. by the time i've spent the money on all this work to the b30, i'm in half way in for a b40. and to top it all off, the house i'm trying to buy is taking WAY longer than i'd like, so until then, i'm stuck in an apartment with all the luxuries that one gets when it comes to working on cars... ie-none.

oh well. guess i've got some decisions to make. feel free to chime in with any advice or opinions, although i think i know what i'm gonna do...


by the way, thanks for all the help fellas

[bubba966]

So your MAF is the same as one from an M50B25TU. Friend of mine has 2 used M50B25TU MAF's sitting around at her place. They both worked fine last time I had them in her 525iT. Not sure what one of those is worth to you, nor do I know offhand if she wants to keep them or not. LMK if you'd be interested in one and I can ask her what her plans are for them.

[skylinergtr]

i thought this too, but ran a check in realoem and got:
Part 13621747155 (Hot-film air mass meter) was found on the following vehicles:


E34: Details on E34
E34 525i Sedan
E34 525i Touring
E34 530i Sedan
E34 530i Touring
E36: Details on E36
E36 325i Sedan
E36 325i Convertible
E36 325is Coupe
E36 M3 Coupe


this has crossed my mind as well


upon more general MAF research (non-e34 specific), i ran across mutliple mentions of a vaccum leak being the cause for a car running better with its MAF disconnected, similar to what janders mentioned.

upone more investigation around my engine bay, i did notice a very pronounced "whooshing" or "sucking" sound when i throttled the engine. what i would like to do is replace my plugs, valve cover gaskets, intake gaskets, and valley pan gaskets, if for no other reason than the learning experience and peace of mind. this will cost $$$

and herein lies my dilemma...

it's not so much the cost as it is the ultimate plan. i bought the car with all intentions of a b40/6spd swap. by the time i've spent the money on all this work to the b30, i'm in half way in for a b40. and to top it all off, the house i'm trying to buy is taking WAY longer than i'd like, so until then, i'm stuck in an apartment with all the luxuries that one gets when it comes to working on cars... ie-none.

oh well. guess i've got some decisions to make. feel free to chime in with any advice or opinions, although i think i know what i'm gonna do...


by the way, thanks for all the help fellas

replace the maf with one from a 540i, and replace the o2 sensors. These parts will be in good use if you decide to do a b40 swap. Stuff like intake gaskets, valley pan, and plugs i wouldnt suggest doing if your heart is set on a b40 swap. Doing intake gaskets/valley pan costs a lot of money in parts. You kind of open a new can of worms. You'll find that your knock sensors arent good, the waterpump might as well be changed since its so easy as its right there. Maybe change the plugs with coppers because its cheap and have a good run with the car before you swap it.

[Sir Montalbon]

replace the maf with one from a 540i

nice!

i have a parked 1/95 e38 with the same MAF i can use for free!

wasn't aware that you can swap these out. the ecu is cool with it?

will probably be a few weeks before i can get at the e38, but good to know.

[PhillyNC]

please shoot me if this is beyond a stupid question. though if you're feeling it, i will gladly accept enlightenment...

installed some euro smileys this weekend (thanks seventhstoned) which, along the way, requierd me to remove my air filter/MAF/intake hose etc to reach some of the more stubborn screws. afterwards, the car ran like shit.

i've already been experiencing a rough idle and the occasional smoke out the tail pipe (burnt oil smoke as far as i can tell) along with a CEL throwing 1213 (secondary o2 rich/lean condition according to Bentley), but this was more of a choking of the car. like, i could floor it in nuertral and the car would barely rise above idle, then suddenly shoot up in rpm's, as if someone suddenly un-choked it. (bad MAF? clogged cats? Axl Foley banana in the tailpipe?)

i disassembled the air filter/MAF/boot assembly again and put it back together making sure everything was snug. no change. then i disconnected the MAF, and everthing smoothed out signifigantly, although the car still idled a little rough.

i'm still learning about the air intake, MAF, and the other assorted intake functions, so hopefully i'm not asking something either a) incredibly stupid, or b) incredibly vague. just hoping someone could either chime in regarding a similar experience, or maybe give me an outline of the things i would need to investigate/eliminate to eventually lead me towards a solution.

TIA

I am currently having the same issue! Someone please help!

[PhillyNC]

please shoot me if this is beyond a stupid question. though if you're feeling it, i will gladly accept enlightenment...

installed some euro smileys this weekend (thanks seventhstoned) which, along the way, requierd me to remove my air filter/MAF/intake hose etc to reach some of the more stubborn screws. afterwards, the car ran like shit.

i've already been experiencing a rough idle and the occasional smoke out the tail pipe (burnt oil smoke as far as i can tell) along with a CEL throwing 1213 (secondary o2 rich/lean condition according to Bentley), but this was more of a choking of the car. like, i could floor it in nuertral and the car would barely rise above idle, then suddenly shoot up in rpm's, as if someone suddenly un-choked it. (bad MAF? clogged cats? Axl Foley banana in the tailpipe?)

i disassembled the air filter/MAF/boot assembly again and put it back together making sure everything was snug. no change. then i disconnected the MAF, and everthing smoothed out signifigantly, although the car still idled a little rough.

i'm still learning about the air intake, MAF, and the other assorted intake functions, so hopefully i'm not asking something either a) incredibly stupid, or b) incredibly vague. just hoping someone could either chime in regarding a similar experience, or maybe give me an outline of the things i would need to investigate/eliminate to eventually lead me towards a solution.

TIA

I am currently having the same issue! Someone please help!

Hey Guys new to the forum so hopefully one of yall can help me out. The Symptoms are as follows:

When I start the car it starts up really rough and the idle acts funny. i also get alot of white smoke from the tail pipe it could just be cause its cold. But it almost sounds like if it would be flooded. I went and changed out the fuel filter per advice of the attendentant at auto zone but no help. I have read forums that say it could be the MAF? i disconnected it but still had the same problem. also when i push the accelerator whether its in park or when im out driving it wont go past 3500 rpm.... Can anyone point me in the right direction. Also i checked the throttle body and there was quite a bit of oil is that normal?

[roadsterred]

Check for oil getting into your intake manifold through your Positive Crankcase Ventilation system. I'm not familiar with the 525i's PCV system.

On 540i's, the Oil Separator diaphragm mounted on the back of the Intake Manifold frequently fails and causes oil to get into the intake manifold and the rear cylinders causing the 02 sensors to react.

[SpiritofBavaria]

I did not realise that cleaning a maf involved disassembly. I thought you just hit it carefully with contact cleaner spray through the circular channels.

Op have you checked your codes ? By now you would have many, check, clear, run the car and recheck.

You may still have to do the disconnect test for each of your driveability sensors. Disconnecting the buggu one will normalise the engine immediately. Your driveability sensors would be the maf, o2, air temp sensor, ects, and your icv.

If your cleaned maf is no longer throwing a code, then disconnect the air temp srnsor. That caused major problems with a friend's 540i.

I assume your plugs and plug wells are ok. Sorry, did not read through all the prior posts. Good luck.


Spirit

Check for oil getting into your intake manifold through your Positive Crankcase Ventilation system. I'm not familiar with the 525i's PCV system.

On 540i's, the Oil Separator diaphragm mounted on the back of the Intake Manifold frequently fails and causes oil to get into the intake manifold and the rear cylinders causing the 02 sensors to react.

+1. Known weakness in the M60. One simple way to check would be to use your phine camera, position it in frint of the throttle body, hold the flap open and take a picture with the flash on.

This is not a problem with the m50, fwiw.

[m60b30530i]

No need to disassemble the MAF just spray it in there.

[kavvmxuh]

well clean out your maf with MAF cleaner found at pretty much any auto parts store.