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 > E46 Xi Forum

E46 Xi Forum
The E46 XI was produced from 01-05 in sedan and touring body styles. Powered by either a 2.5L inline 6 in the 325xi or a 3.0L inline 6 330xi. Discuss all thing about BMW AWD E46 'Xi' here.

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 12-03-2010, 02:19 PM   #1
Chadrobb4
Registered User
 
Join Date: Oct 2009
Location: Illinois
Posts: 39
My Ride: 2003 BMW 325xi
03 325xi Idle Surge

Hi all, I have an 03 325xi that is surging when coming to a stop/idle. Right around 1k RPM it will surge quickly 500RPM and settle out. I know there are a few threads out there on this topic.

Ill be checking codes and look for leaks, but most of that has already been changed and no check engine lights.

One thing I do need to do is replace the thermostat as it threw a P0128 (I know I just said it hasnt had any check engine lights, hasnt had any new check engine lights) and the engine is running very cold with the winter temps coming in.

Is the most likely cause related to the fact it needs a thermostat? Also thinking about changing the VANOS seals while I have the mechanical fan out.

Any info is greatly appreciated.
Chadrobb4 is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 12-03-2010, 02:34 PM   #2
Capt1014
Registered User
 
Join Date: Dec 2009
Location: Massachusetts
Posts: 167
My Ride: 2002 325xi
I have the same thing happening to mine, but it's always been like that since I bought it a year ago (02 325XI)
__________________
Mods, Bilstein HD Struts & Shocks, H&R Springs, F1 Racing Stage 2 Clutch & Chromoly Ltw Flywheel...more to come.


Overkill is an often underrated state of achivement!
Capt1014 is offline   Reply With Quote
Old 12-03-2010, 02:49 PM   #3
Chadrobb4
Registered User
 
Join Date: Oct 2009
Location: Illinois
Posts: 39
My Ride: 2003 BMW 325xi
Its quite annoying! I fix one thing, another pops up.
Chadrobb4 is offline   Reply With Quote
Old 12-03-2010, 03:38 PM   #4
SamDoe1
Registered User
 
Join Date: Oct 2010
Location: Minnesnowta
Posts: 3,576
My Ride: Clubs baby seals
If you have to change the t-stat then just do it and see what happens. Other things to look at would be the camshaft position sensor and/or the coolant temperature sensor.
SamDoe1 is offline   Reply With Quote
Old 12-09-2010, 04:53 PM   #5
Capt1014
Registered User
 
Join Date: Dec 2009
Location: Massachusetts
Posts: 167
My Ride: 2002 325xi
Quote:
Originally Posted by SamDoe1 View Post
If you have to change the t-stat then just do it and see what happens. Other things to look at would be the camshaft position sensor and/or the coolant temperature sensor.
Coolant temp sensor can make the idle surge?
__________________
Mods, Bilstein HD Struts & Shocks, H&R Springs, F1 Racing Stage 2 Clutch & Chromoly Ltw Flywheel...more to come.


Overkill is an often underrated state of achivement!
Capt1014 is offline   Reply With Quote
Old 12-09-2010, 05:29 PM   #6
SamDoe1
Registered User
 
Join Date: Oct 2010
Location: Minnesnowta
Posts: 3,576
My Ride: Clubs baby seals
Quote:
Originally Posted by Capt1014 View Post
Coolant temp sensor can make the idle surge?
I would think so, if the coolant is cold the engine will idle higher than if the coolant is hot. Turn your car on on a cold day and it will idle quite a bit higher than after you drive it for 20 minutes. Any variation in this signal could vary the idle speed of the engine.
SamDoe1 is offline   Reply With Quote
Old 12-09-2010, 05:40 PM   #7
E-rock
Registered User
 
Join Date: Aug 2009
Location: Philly
Posts: 310
My Ride: '01 330xi
My previous car had an idle surge in cold weather. Very annoying. It ended up being a temp sensor.
__________________

"So when you go for a drive, remember to leave your murderous anger where it belongs - at home."
E-rock is offline   Reply With Quote
Old 12-09-2010, 09:26 PM   #8
Kubica
Registered User
 
Join Date: Apr 2008
Location: Boston
Posts: 4,487
My Ride: 2003 325xi
It's probably the DISA. Search for the video on here that shows the difference between a broken and new DISA valve.
Kubica is offline   Reply With Quote
Old 12-09-2010, 10:40 PM   #9
mp333
Registered User
 
Join Date: Nov 2009
Location: EastCoast
Posts: 315
My Ride: 2003 325XI
Try disconnecting the DISA, see if there's any change. Also is the ICV clean?
mp333 is offline   Reply With Quote
Old 12-10-2010, 09:43 AM   #10
E-rock
Registered User
 
Join Date: Aug 2009
Location: Philly
Posts: 310
My Ride: '01 330xi
Quote:
Originally Posted by mp333 View Post
Try disconnecting the DISA, see if there's any change. Also is the ICV clean?
I've never known or experienced a dirty ICV to cause the rise and fall the OP described. Rough idle, yes, but not a rhythmic, surging idle. Couldn't hurt to clean the ICV if it hasn't been done in the past year or two but my guess is a temp sensor has gone bad, or worse, coolant isn't coming into contact with the sensor.
__________________

"So when you go for a drive, remember to leave your murderous anger where it belongs - at home."
E-rock is offline   Reply With Quote
Old 12-10-2010, 02:51 PM   #11
Kubica
Registered User
 
Join Date: Apr 2008
Location: Boston
Posts: 4,487
My Ride: 2003 325xi
Quote:
Originally Posted by E-rock View Post
I've never known or experienced a dirty ICV to cause the rise and fall the OP described. Rough idle, yes, but not a rhythmic, surging idle. Couldn't hurt to clean the ICV if it hasn't been done in the past year or two but my guess is a temp sensor has gone bad, or worse, coolant isn't coming into contact with the sensor.
Nah, it's the DISA.
Kubica is offline   Reply With Quote
Old 12-10-2010, 03:38 PM   #12
Capt1014
Registered User
 
Join Date: Dec 2009
Location: Massachusetts
Posts: 167
My Ride: 2002 325xi
Quote:
Originally Posted by kubica View Post
nah, it's the disa.
disa?
__________________
Mods, Bilstein HD Struts & Shocks, H&R Springs, F1 Racing Stage 2 Clutch & Chromoly Ltw Flywheel...more to come.


Overkill is an often underrated state of achivement!
Capt1014 is offline   Reply With Quote
Old 12-10-2010, 03:55 PM   #13
nickchuck
Registered User
 
Join Date: Dec 2008
Location: Central Jerz
Posts: 140
My Ride: 325xi (Topaz)
Probably the DISA Valve. http://www.ecstuning.com/Search/11617544806/ES25794/ You can disconnect this on your own very easilly. If it flaps open and closed (no spring tension) it's broken.

If not check the coding of your computer. I had mine updated with the newest software ($129 at the dealer) and all my idling issues dissapeared. This may be a good idea if you haven't done it recently anyway.
nickchuck is offline   Reply With Quote
Old 12-10-2010, 05:44 PM   #14
Rickna
Registered User
 
Join Date: Nov 2008
Location: West Haven, CT, USA
Posts: 1,995
My Ride: '01 330xi - '09 IS-F
Quote:
Originally Posted by Capt1014 View Post
disa?
Air Adjustment Unit
__________________

2001 BMW 330xi
2009 Lexus IS-F
Rickna 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 12:40 PM.


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