E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 07-29-2015, 06:43 PM   #1
xDecrypted
Registered User
 
Join Date: Jan 2015
Location: Alabama
Posts: 87
My Ride: 2003 BMW 325i
2003 325i MAF urgent help

I'm new to the forums I tried searching but no luck. A little help please my MAF may be going bad but don't know. Coming to a stop my cars rpm will go up and down between 500 and 1k rev. Sometimes when I hit the gas it shuts off I unplugged the MAF and seems to be okay then I plug it in and the car dies.
Since it dies is it going bad ?
xDecrypted is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 07-29-2015, 07:24 PM   #2
xDecrypted
Registered User
 
Join Date: Jan 2015
Location: Alabama
Posts: 87
My Ride: 2003 BMW 325i
Bump
xDecrypted is offline   Reply With Quote
Old 07-29-2015, 09:02 PM   #3
djacs1
Registered User
 
Join Date: Mar 2007
Location: TX
Posts: 99
My Ride: 2001 325i
Search more, there's a lot of threads here about this kind of engine problems (rough idle, swinging rpm, stall). This may not be your MAF.

Try jfoj thread:
http://forum.e46fanatics.com/showthread.php?t=897616

Good Luck
djacs1 is offline   Reply With Quote
Old 07-29-2015, 09:26 PM   #4
Stinger9
Registered User
 
Join Date: Sep 2011
Location: New York
Posts: 9,474
My Ride: '04 330Ci
cleaned throttle body and ICV?
checked for air leaks?
Stinger9 is offline   Reply With Quote
Old 07-29-2015, 09:42 PM   #5
jfoj
OEM ///Member
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 22,857
My Ride: 330CiC, M5, X5, E93
Its not likely the MAF. I assume the SES/CEL/MIL is on, if not you have another problem to address.

Check codes, Freeze Frame and Fuel Trim info and report back.

2 words, Vacuum Leaks!
__________________
Solve your misfires, lean codes, rough idle - http://forum.e46fanatics.com/showthread.php?t=897616

Fuel pump failures - http://forum.e46fanatics.com/showthread.php?t=929501

Temp Info - http://forum.e46fanatics.com/showthread.php?t=964491

Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

E46/E39 GM5 Door Lock Info - www.bmwgm5.com

Lower hose temp switch O-ring - BMW #13621743299

Last edited by jfoj; 07-29-2015 at 09:42 PM.
jfoj is offline   Reply With Quote
Old 07-30-2015, 10:51 PM   #6
xDecrypted
Registered User
 
Join Date: Jan 2015
Location: Alabama
Posts: 87
My Ride: 2003 BMW 325i
Quote:
Originally Posted by jfoj View Post
Its not likely the MAF. I assume the SES/CEL/MIL is on, if not you have another problem to address.

Check codes, Freeze Frame and Fuel Trim info and report back.

2 words, Vacuum Leaks!
Seems like it might be the MAF sensor as I unplugged it, drove around and it didn't seem to rev between 500 and 1k anymore. Didn't see vacuum leaks. Will check more throughly and also seems that my PCV crankcase needs to be changed black smoke came out from the exhaust when reving it up. Any idea ? It's burned my oil up

Last edited by xDecrypted; 07-30-2015 at 10:51 PM.
xDecrypted is offline   Reply With Quote
Old 07-30-2015, 10:54 PM   #7
jfoj
OEM ///Member
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 22,857
My Ride: 330CiC, M5, X5, E93
Well, you need to understand a few things here.

1. Unplugging the MAF puts the engines fuel Map into a default mode that is slightly Rich which will cover up/mask Lean problems.

2. If you had an OBDII scan tool that supported Live/Realtime Data, you could monitor the MAF reading and Fuel Trim values and figure out what is going on.

You can choose to replace the MAF, but this is not likely the primary cause of your problems.
__________________
Solve your misfires, lean codes, rough idle - http://forum.e46fanatics.com/showthread.php?t=897616

Fuel pump failures - http://forum.e46fanatics.com/showthread.php?t=929501

Temp Info - http://forum.e46fanatics.com/showthread.php?t=964491

Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

E46/E39 GM5 Door Lock Info - www.bmwgm5.com

Lower hose temp switch O-ring - BMW #13621743299
jfoj is offline   Reply With Quote
Old 07-31-2015, 12:11 AM   #8
xDecrypted
Registered User
 
Join Date: Jan 2015
Location: Alabama
Posts: 87
My Ride: 2003 BMW 325i
Quote:
Originally Posted by jfoj View Post
Well, you need to understand a few things here.

1. Unplugging the MAF puts the engines fuel Map into a default mode that is slightly Rich which will cover up/mask Lean problems.

2. If you had an OBDII scan tool that supported Live/Realtime Data, you could monitor the MAF reading and Fuel Trim values and figure out what is going on.

You can choose to replace the MAF, but this is not likely the primary cause of your problems.
Also could be disa valve as I hear rattling in there.
Any idea about the black smoke and burned up oil
xDecrypted is offline   Reply With Quote
Old 07-31-2015, 02:00 AM   #9
NumbaOneNewb
Registered User
 
Join Date: Jul 2012
Location: Portland, OR
Posts: 3,366
My Ride: 2003 330CI Silver
Could be the entire engine. We can guess all day long but if you want a pin point answer, researching and investigating is needed
__________________
Portland Metro: ECU updates, Euro tune, euro corner delete, air bag light, DSC light, cluster and any led color change, soldering work, transponders for keys, and all custom work related to computer or electronics.DIY AK90 A walk through on coding your mcu and transponders EWS3 How to make your own key (ak90 review)
NumbaOneNewb is offline   Reply With Quote
Old 07-31-2015, 09:37 AM   #10
jfoj
OEM ///Member
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 22,857
My Ride: 330CiC, M5, X5, E93
Quote:
Originally Posted by xDecrypted View Post
Also could be disa valve as I hear rattling in there.
Any idea about the black smoke and burned up oil
Not likely the MAF as I stated.

DISA's are problems, they do not last forever and can cause Lean problems, idle issues and stalling. BUT so do MANY other things on these engines like intake boots and CCV and CCV hoses.

Black smoke can be due to these or a cool running engine.

What you need to do is gather DATA with an OBDII smart phone App.

Need to see Logs for engine, DTC's (trouble codes), Freeze Frame and Live/Realtime data for MAF, Fuel Trims and O2 sensors.

Get an OBDII smart phone/tablet App and interface, typically $30 or less. These Apps are usually best for drivability issues and they support Emission Readiness Monitor Status, Freeze Frame and Live/Realtime data. They are also great for Logging data for review after the car has been driven and can really help find unusual problems.

Android - Touch Scan for $3.95 and ELM327 OBDII to Bluetooth interface.

iProduct - OBD Fusion for $9.95 and ELM327 OBDII to Wifi interface.

I usually suggest getting the OBDII interfaces from Amazon if you are located in the US/North America. Make sure you choose an interface that indicates that the order will be "Fulfilled by Amazon" otherwise you may be waiting for WEEKS for an interface to arrive from Asia. Ebay is another option, but pay attention where the interface will be shipped from, again weeks for an interface from Asia, so if you can wait and want to try to save some money, go for it, but if you need an interface soon, choose wisely.
__________________
Solve your misfires, lean codes, rough idle - http://forum.e46fanatics.com/showthread.php?t=897616

Fuel pump failures - http://forum.e46fanatics.com/showthread.php?t=929501

Temp Info - http://forum.e46fanatics.com/showthread.php?t=964491

Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

E46/E39 GM5 Door Lock Info - www.bmwgm5.com

Lower hose temp switch O-ring - BMW #13621743299
jfoj is offline   Reply With Quote
Reply

Tags
idle, maf, mass air flow sensor

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 04:26 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
(c) 1999 - 2016 performanceIX Inc - privacy policy - terms of use