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 03-30-2012, 02:49 PM   #1
328ci906
Registered User
 
Join Date: May 2010
Location: Scranton, PA
Posts: 432
My Ride: 2003 M3
M3 Running Cold w/ New Thermostat??

I just picked up my first M3 last Friday knowing that it was running cold. I assumed it needed a new thermostat, but after installing a new one it still runs cold. It's definitly an improvement over how it ran before, but the needle still isn't dead center. More often than not it favors the cold side. Is it possible I got a bad thermostat? Or could it be something else?
__________________
2003 ///M3 6spd Jet Black/Cinnamon (I Loan Valve Adjustment Tools! PM me...)
328ci906 is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 03-30-2012, 02:51 PM   #2
aikmanson
Registered User
 
Join Date: Nov 2011
Location: Kingston/Cortland NY
Posts: 238
My Ride: 2000 323ci
Quote:
Originally Posted by 328ci906 View Post
I just picked up my first M3 last Friday knowing that it was running cold. I assumed it needed a new thermostat, but after installing a new one it still runs cold. It's definitly an improvement over how it ran before, but the needle still isn't dead center. More often than not it favors the cold side. Is it possible I got a bad thermostat? Or could it be something else?
Just out of curiosity, have you checked the actual temperature using the OBC function? It could be possible your gauge is reading wrong. Always look into the simple things first.
__________________
2003 Jeep Wrangler Rubicon
2000 BMW 323ci
1995 Saab 900 SE - JZW Stage 4
aikmanson is offline   Reply With Quote
Old 03-30-2012, 02:59 PM   #3
328ci906
Registered User
 
Join Date: May 2010
Location: Scranton, PA
Posts: 432
My Ride: 2003 M3
Yeah I was thinking that, but even my oil temp gauge never hits center, it always stays below 210 even when I beat on it.
__________________
2003 ///M3 6spd Jet Black/Cinnamon (I Loan Valve Adjustment Tools! PM me...)
328ci906 is offline   Reply With Quote
Old 03-30-2012, 03:01 PM   #4
rayryz
Registered User
 
Join Date: Nov 2011
Location: texas, usa
Posts: 42
My Ride: 2003, 325i
It happened to me before, the new thermostat was bad, in my case I bought a cheap one on Ebay (around 30$), I returned it and bought another one from advanced auto (around 80$) and it worked fine.
rayryz is offline   Reply With Quote
Old 03-30-2012, 03:06 PM   #5
328ci906
Registered User
 
Join Date: May 2010
Location: Scranton, PA
Posts: 432
My Ride: 2003 M3
Yeah, I guess it's possible. I bought this thermostat new from my local dealer. But I'm not convinced its bad, only because it is an improvement over the old one. So I'm thinking something else might be wrong.
__________________
2003 ///M3 6spd Jet Black/Cinnamon (I Loan Valve Adjustment Tools! PM me...)
328ci906 is offline   Reply With Quote
Old 03-30-2012, 03:23 PM   #6
jfoj
Registered User
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 10,114
My Ride: '06 330CiC, '03 M5
A few things you need to know, not sure if you had a normal E46 before this M3?

The standard E46 temp gauge is buffered and it always sits dead center over a 50+F range. Only if it goes over center you should be very careful.

The M cars have much colder thermostats and the temp gauge is not buffered. Your car should have a 79C stat, which means a 175F.

Your temp gauge should stay about 11-11:30 position until the outside temp gets to 65-70F then it may start to hit the dead vertical position?

Not sure on the M3, but the oil temp usually is going to be about 10-20F above the coolant temp? Not sure the M3 has the oil-water-air heat exchanger like my M5, but I assume it has some sort of oil cooler?

Best to check the link below in my signature for the Hidden OBC menu, bring up the coolant temp and watch it. Should not drop below 78-79 once it warms up. If this is where your temps are with outside at or below 70F then you are probably normal.

The M is a very different car than the standard E46 in many ways, so you need to read up on it.
__________________
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

Last edited by jfoj; 03-30-2012 at 03:26 PM.
jfoj is online now   Reply With Quote
Old 03-30-2012, 06:34 PM   #7
aikmanson
Registered User
 
Join Date: Nov 2011
Location: Kingston/Cortland NY
Posts: 238
My Ride: 2000 323ci
Quote:
Originally Posted by jfoj View Post
A few things you need to know, not sure if you had a normal E46 before this M3?

The standard E46 temp gauge is buffered and it always sits dead center over a 50+F range. Only if it goes over center you should be very careful.

The M cars have much colder thermostats and the temp gauge is not buffered. Your car should have a 79C stat, which means a 175F.

Your temp gauge should stay about 11-11:30 position until the outside temp gets to 65-70F then it may start to hit the dead vertical position?

Not sure on the M3, but the oil temp usually is going to be about 10-20F above the coolant temp? Not sure the M3 has the oil-water-air heat exchanger like my M5, but I assume it has some sort of oil cooler?

Best to check the link below in my signature for the Hidden OBC menu, bring up the coolant temp and watch it. Should not drop below 78-79 once it warms up. If this is where your temps are with outside at or below 70F then you are probably normal.

The M is a very different car than the standard E46 in many ways, so you need to read up on it.
Great information here!
__________________
2003 Jeep Wrangler Rubicon
2000 BMW 323ci
1995 Saab 900 SE - JZW Stage 4
aikmanson is offline   Reply With Quote
Old 03-30-2012, 06:38 PM   #8
MasterC17
Registered User
 
Join Date: Oct 2009
Location: Massachusetts
Posts: 585
My Ride: hates A/C & Sunroofs
As jfoj stated, the M3 needle is not buffered, and to run a little less than straight up is entirely normal (around 80C). The oil will usually stay right below the center 210f mark unless you beat on it (6k RPM plus multiple times). Tracking the car the oil temps can hit almost 300f if its really hot out and you are really beating it.
MasterC17 is offline   Reply With Quote
Old 03-30-2012, 09:52 PM   #9
328ci906
Registered User
 
Join Date: May 2010
Location: Scranton, PA
Posts: 432
My Ride: 2003 M3
Thanks for all the info guys! I spent some more time searching the forums and have been reading exactly what you've said. People that DD their M3's in colder weather will show a slightly cold coolant temp on the gauge. It's been just about 45 degrees here for the past week or so, so it makes sense that my temp gauge wouldnt hit dead center. I feel alot better now that I know why my car has been running cold. I was afraid something else was broken...
__________________
2003 ///M3 6spd Jet Black/Cinnamon (I Loan Valve Adjustment Tools! PM me...)
328ci906 is offline   Reply With Quote
Old 03-31-2012, 12:20 AM   #10
TerraPhantm
Registered User
 
Join Date: Feb 2008
Location: Mountain Top
Posts: 5,918
My Ride: 2005 M3 Coupe
Quote:
Originally Posted by 328ci906 View Post
I just picked up my first M3 last Friday knowing that it was running cold. I assumed it needed a new thermostat, but after installing a new one it still runs cold. It's definitly an improvement over how it ran before, but the needle still isn't dead center. More often than not it favors the cold side. Is it possible I got a bad thermostat? Or could it be something else?
Completely normal. The M3's gauge isn't as buffered as the non-M. It's setup so that it's dead center from 83 to 85 degrees. It'll lean left below that and lean right above that. The m3's thermostat opens up at 80 degrees, so it will lean left for the most part. I confirmed this when I was studying the M and non-M eeproms; there is nearly no buffer in the M3 while the non-M buffer zone is gigantic. I'll see if I can dig up what temperatures the 1/4 and 3/4 dots represent.

Fwiw my oil temperature is around 180 in this weather. When it warns up, it's more like 190-200. I have to really beat on it to get it above 210
__________________

Last edited by TerraPhantm; 03-31-2012 at 12:23 AM.
TerraPhantm is offline   Reply With Quote
Old 03-31-2012, 12:51 PM   #11
328ci906
Registered User
 
Join Date: May 2010
Location: Scranton, PA
Posts: 432
My Ride: 2003 M3
Quote:
Originally Posted by TerraPhantm View Post
Completely normal. The M3's gauge isn't as buffered as the non-M. It's setup so that it's dead center from 83 to 85 degrees. It'll lean left below that and lean right above that. The m3's thermostat opens up at 80 degrees, so it will lean left for the most part. I confirmed this when I was studying the M and non-M eeproms; there is nearly no buffer in the M3 while the non-M buffer zone is gigantic. I'll see if I can dig up what temperatures the 1/4 and 3/4 dots represent.

Fwiw my oil temperature is around 180 in this weather. When it warns up, it's more like 190-200. I have to really beat on it to get it above 210
Ok that makes me feel a lot better. That's exactly the kind of temps I am seeing with the new thermostat. Now I just have to rebuild my Diff seals to make it 100%. I was just waiting to place my order for diff seals until I had this cooling figured out. Thanks for the tips guys
__________________
2003 ///M3 6spd Jet Black/Cinnamon (I Loan Valve Adjustment Tools! PM me...)
328ci906 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 01:11 AM.


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