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 11-13-2012, 11:36 AM   #1
thefrog1394
Registered User
 
Join Date: Jul 2009
Location: Columbus, Ohio
Posts: 966
My Ride: e46- 1999 323i
Deviation rich (both banks), rough idle

I am getting codes for lambda adaptation deviation rich in both banks. I also have an idle drop problem (engine idle RPM will drop and feel like its about to stall before recovering).

I tried unplugging the MAF and the idle drop issue seems improved but not completely solved.

I tried spraying carb cleaner near vacuum leak prone places but found nothing (near intake boot, CCV). Also, wouldn't deviation rich indicate that it is NOT a vacuum leak? (That would cause deviation lean, right?)

I am ruling out O2 sensors since it is both banks. Good assumption?

This leaves in my mind just the MAF sensor itself. I would rather not spend the money to replace the MAF sensor unless I am pretty confident that that is the problem. This is on my 01 330Ci. I also have a 99 323i, anyone know if these MAF sensors are interchangable? Appear to be different part numbers on realOEM so guessing thats a NO.

Anyone have any input for further ways I can diagnose without beginning to throw money at the problem?

Thanks,

Dan
__________________

Photo in Cleveland, Ohio
1999 323i - 210,000 miles and counting.
Rear Wheel Bearing Tool (SitTools B90) Rental, ~$60
thefrog1394 is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 11-13-2012, 11:40 AM   #2
jfoj
Registered User
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 9,283
My Ride: '06 330CiC, '03 M5
Not likely the MAF sensor, O2 sensors or any other sensors.

Deviation rich means you are running LEAN.

You likely have a vacuum leak.

Check the lower CCV oil return hose, fuel pressure regulator vacuum line at the filter and see the first 2 links below in my signature.
__________________
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, Temps, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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

Lower hose fan switch O-ring - BMW #13621743299
jfoj is offline   Reply With Quote
Old 11-13-2012, 11:47 AM   #3
thefrog1394
Registered User
 
Join Date: Jul 2009
Location: Columbus, Ohio
Posts: 966
My Ride: e46- 1999 323i
Quote:
Originally Posted by jfoj View Post
Not likely the MAF sensor, O2 sensors or any other sensors.

Deviation rich means you are running LEAN.

You likely have a vacuum leak.

Check the lower CCV oil return hose, fuel pressure regulator vacuum line at the filter and see the first 2 links below in my signature.
Ahh, ok, had it backwards. Makes sense I guess (ECU trying to richen fuel/air mix and deviated too far in that direction). Thanks. I will continue searching for a vacuum leak. Do you or anyone have suggestions on any other creative ways of tracking it down besides just checking the common places?
__________________

Photo in Cleveland, Ohio
1999 323i - 210,000 miles and counting.
Rear Wheel Bearing Tool (SitTools B90) Rental, ~$60
thefrog1394 is offline   Reply With Quote
Old 11-13-2012, 04:12 PM   #4
fernando629
Registered User
 
Join Date: Jun 2012
Location: El Salvador
Posts: 52
My Ride: 325Xi 2001
Hi OP, keep us posted.
fernando629 is offline   Reply With Quote
Old 11-13-2012, 04:59 PM   #5
jfoj
Registered User
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 9,283
My Ride: '06 330CiC, '03 M5
Smoke test, spray brake cleaner, mechanics stethoscope with the transducer removed and extending the hose to listen for vacuum leaks.

But except for crack valve cover or bad valve cover and a few other odd things a visual inspection is really the best solution. You WILL find problems visually inspecting the obvious culprits and you will likely find other problems as well.
__________________
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, Temps, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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

Lower hose fan switch O-ring - BMW #13621743299
jfoj is offline   Reply With Quote
Old 11-13-2012, 08:35 PM   #6
thefrog1394
Registered User
 
Join Date: Jul 2009
Location: Columbus, Ohio
Posts: 966
My Ride: e46- 1999 323i
Quote:
Originally Posted by jfoj View Post
Smoke test, spray brake cleaner, mechanics stethoscope with the transducer removed and extending the hose to listen for vacuum leaks.

But except for crack valve cover or bad valve cover and a few other odd things a visual inspection is really the best solution. You WILL find problems visually inspecting the obvious culprits and you will likely find other problems as well.
Valve cover gasket is indeed bad and leaking, but I would be very surprised if this could let enough air in to set off adaptation errors and cause a noticeable idle drop. My valve cover gasket was leaking way worse and the SAP vacuum line was cracked really bad on my other e46 and no CEL and perfect idle...
__________________

Photo in Cleveland, Ohio
1999 323i - 210,000 miles and counting.
Rear Wheel Bearing Tool (SitTools B90) Rental, ~$60
thefrog1394 is offline   Reply With Quote
Old 11-13-2012, 09:13 PM   #7
jfoj
Registered User
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 9,283
My Ride: '06 330CiC, '03 M5
You would be surprised!!!

Also you can have oil leaking and not a bad air leak and you can have a bad air leak with no oil leaking!

Cracked valve covers are also another very common issue as well.

Do not discount the valve cover. A valve cover leak will likely not respond to a brake cleaner test very well, however, if you smoke test the crankcase you will find the valve cover leak quickly.
__________________
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, Temps, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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

Lower hose fan switch O-ring - BMW #13621743299
jfoj is offline   Reply With Quote
Old 11-13-2012, 10:30 PM   #8
thefrog1394
Registered User
 
Join Date: Jul 2009
Location: Columbus, Ohio
Posts: 966
My Ride: e46- 1999 323i
Hmm, ok. Well thanks for the advice, I'll definitely tackle the valve cover gasket before trying anything else then.
__________________

Photo in Cleveland, Ohio
1999 323i - 210,000 miles and counting.
Rear Wheel Bearing Tool (SitTools B90) Rental, ~$60
thefrog1394 is offline   Reply With Quote
Old 09-22-2013, 10:16 PM   #9
thefrog1394
Registered User
 
Join Date: Jul 2009
Location: Columbus, Ohio
Posts: 966
My Ride: e46- 1999 323i
Update: valve cover gasket replaced, still have the same issue. Can't find any vacuum leaks. I suppose it could be a failed MAF, I just hate to blindly spend the money replacing it.
__________________

Photo in Cleveland, Ohio
1999 323i - 210,000 miles and counting.
Rear Wheel Bearing Tool (SitTools B90) Rental, ~$60
thefrog1394 is offline   Reply With Quote
Reply

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 05:00 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use