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 12-30-2012, 08:59 AM   #21
chrism24
Registered User
 
Join Date: Aug 2012
Location: Colorado
Posts: 68
My Ride: 2005 325i
Quote:
Originally Posted by jfoj View Post
The real question is what is the coolant temperature?

These thermostats fail open ALL the time and the engine can run too cold, when this happens, fuel economy is the first thing to take a dive.

95C is about typical, maybe slightly higher.

Hidden OBC will answer this question in a single trip.
I'm up snowboarding right now (and obviously I made someone else drive to keep my baby warm and dry at home...) but ill be able to check coolant temp tommorow probably and then ill post back
__________________
chrism24 is offline   Reply With Quote
Old 12-30-2012, 12:25 PM   #22
trj
Registered User
 
Join Date: Mar 2011
Location: Denver
Posts: 2,924
My Ride: 325Ci
Quote:
Originally Posted by BBBoy323i View Post
Not to thread jack but wasn't your car getting bad mpg couple months ago? What changed?
Yah. I was getting around 18 mpg. Changed the plugs, fuel filter, boots, vcg, and started going easy on the throttle.

I still feel I can get more mpg's out of it but gave up trying. 21 is a lot better than 18.
__________________

Last edited by trj; 12-30-2012 at 12:25 PM.
trj is offline   Reply With Quote
Old 12-30-2012, 01:37 PM   #23
Stinger9
Registered User
 
Join Date: Sep 2011
Location: New York
Posts: 7,754
My Ride: '04 330Ci
Quote:
Originally Posted by jfoj View Post

Hidden OBC will answer this question in a single trip.
Guess we should post this pdf more frequently:

Last edited by Stinger9; 05-08-2014 at 05:40 PM.
Stinger9 is offline   Reply With Quote
Old 12-30-2012, 02:04 PM   #24
chrism24
Registered User
 
Join Date: Aug 2012
Location: Colorado
Posts: 68
My Ride: 2005 325i
Quote:
Originally Posted by Stinger9 View Post
Guess we should post this pdf more frequently:
Thanks
chrism24 is offline   Reply With Quote
Old 12-30-2012, 04:39 PM   #25
chrism24
Registered User
 
Join Date: Aug 2012
Location: Colorado
Posts: 68
My Ride: 2005 325i
Ok so after a drive of maybe 20min with a little city, mostly highway, and then a little bit of parking lot driving the highest the coolant temp got was 71*C and it was 31*F out...any thoughts?
Attached Thumbnails
Click image for larger version

Name:	image.jpg
Views:	41
Size:	110.3 KB
ID:	484039  
chrism24 is offline   Reply With Quote
Old 12-30-2012, 04:48 PM   #26
Stinger9
Registered User
 
Join Date: Sep 2011
Location: New York
Posts: 7,754
My Ride: '04 330Ci
that's too low, but I'd want a longer test to give the engine time to fully heat up.
Stinger9 is offline   Reply With Quote
Old 12-30-2012, 05:06 PM   #27
chrism24
Registered User
 
Join Date: Aug 2012
Location: Colorado
Posts: 68
My Ride: 2005 325i
On the way home despite hitting 100mph the highest the coolant got was 78C (and that only happened at a stop light, when I was doing 100 it was at 68C). So is it my thermostat?
chrism24 is offline   Reply With Quote
Old 12-30-2012, 05:09 PM   #28
chrism24
Registered User
 
Join Date: Aug 2012
Location: Colorado
Posts: 68
My Ride: 2005 325i
Quote:
Originally Posted by Stinger9 View Post
that's too low, but I'd want a longer test to give the engine time to fully heat up.
So go for a longer drive? How long?

Last edited by chrism24; 12-30-2012 at 05:14 PM.
chrism24 is offline   Reply With Quote
Old 12-30-2012, 05:16 PM   #29
Stinger9
Registered User
 
Join Date: Sep 2011
Location: New York
Posts: 7,754
My Ride: '04 330Ci
Quote:
Originally Posted by chrism24 View Post
On the way home despite hitting 100mph the highest the coolant got was 78C (and that only happened at a stop light, when I was doing 100 it was at 68C). So is it my thermostat?
If it was me, I'd now replace the thermostat just so you'd know for sure that it is good. That is not working properly.
Stinger9 is offline   Reply With Quote
Old 12-30-2012, 05:40 PM   #30
WDE46
Registered User
 
Join Date: Sep 2012
Location: Virgo Supercluster
Posts: 8,663
My Ride: 2004 330Ci OBM
Quote:
Originally Posted by chrism24 View Post
Ok so after a drive of maybe 20min with a little city, mostly highway, and then a little bit of parking lot driving the highest the coolant temp got was 71*C and it was 31*F out...any thoughts?
20 minutes is plenty of time for the coolant to reach the norml 95C. Your thermostat is stuck open. Replace it and rejoice at the normal temps you shll receive.
WDE46 is offline   Reply With Quote
Old 12-30-2012, 05:55 PM   #31
chrism24
Registered User
 
Join Date: Aug 2012
Location: Colorado
Posts: 68
My Ride: 2005 325i
So what other side-effects would a broken thermostat bring?
chrism24 is offline   Reply With Quote
Old 12-30-2012, 06:09 PM   #32
WDE46
Registered User
 
Join Date: Sep 2012
Location: Virgo Supercluster
Posts: 8,663
My Ride: 2004 330Ci OBM
Quote:
Originally Posted by chrism24 View Post
So what other side-effects would a broken thermostat bring?
Not anything that will hurt the engine. It can hurt fuel economy because the engine doesn't reach operating temperature. That's about it. I drove mine with a broken thermostat for a few months.
WDE46 is offline   Reply With Quote
Old 12-30-2012, 09:48 PM   #33
jfoj
Registered User
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 9,523
My Ride: '06 330CiC, '03 M5
20 minutes is plenty of time for the engine to fully warm up. A side effect of a bad stat is also slow and long warm up times. Your car should likely be fully warmed up within about 10 minutes of driving.

Side effects are poor fuel economy and extra mayonnaise in the crankcase. What happens the oil take a lot longer to warm up as compared to the coolant. So you risk not cooking water vapor out of the crankcase as well as the CCV possibly freezing up and possibly sucking the oil out of the crankcase.

You may also risk some accelerated engine wear due to slow warm up. I believe the typical operational temp should be close to 95C as I recall? I do not drive the E46 often, so I do not recall what the typical temps run. I will try to check my E46 sometime this week to confirm.
__________________
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 online now   Reply With Quote
Old 12-30-2012, 11:27 PM   #34
HacksawMark
OEM ///Member
 
HacksawMark's Avatar
 
Join Date: Oct 2012
Location: Portland, OR
Posts: 1,101
My Ride: 2014 Subaru XV
Quote:
Originally Posted by Stinger9 View Post
Guess we should post this pdf more frequently:
Thanks for the link!
HacksawMark is offline   Reply With Quote
Old 01-01-2013, 09:26 AM   #35
yappering
Registered User
 
Join Date: Jan 2012
Location: Atlanta
Posts: 15
My Ride: 323i
Last tank I got about 16 mpg. 250 miles for a tank of about 15.4 gal. No check engine lights are on, no misfires. Used PA Soft and did not pull any codes. I do mostly city driving with a fair amount of stop and go, but I am not slamming on the throttle and I do some highway driving. I have a stick shift 323i. The temperature gauge gets right to the middle when the car warms up. I notice that the mpg indicator flies down to 12 mpg with the slightest application of throttle. For example if I am coming out of a rolling stop and am in first or second gear, it will hit 12 mpg even if I slowly accelerate to 30 mph. Additionally, if I am going down a gradient, such a parking garage and the car is in gear and I am applying a small amount of throttle, the mpg indicator flies to 12 mpg. Any thoughts?
yappering is offline   Reply With Quote
Old 01-01-2013, 09:48 AM   #36
Stinger9
Registered User
 
Join Date: Sep 2011
Location: New York
Posts: 7,754
My Ride: '04 330Ci
Quote:
Originally Posted by yappering View Post
Any thoughts?
Yes, consider the mpg gauge entertainment, not something to seriously use to check mpg. Every car will plunge to 12 mpg with a slight bit of acceleration. It's only the preponderance of light cruising that allows us to average mileage up in the mid twenties or better.
If you want to get serious about improving mpg, first get serious about documenting things. Write down your odometer reading and take the reading from the pump in gallons when filling to do your calculations.

Next start going thru the list of normal things that can affect mpg to bring your engine up to standard. Air leaks, O2 sensors in good shape?, MAF good, etc. for instance.

Last edited by Stinger9; 01-01-2013 at 10:22 AM.
Stinger9 is offline   Reply With Quote
Old 01-01-2013, 11:00 AM   #37
yappering
Registered User
 
Join Date: Jan 2012
Location: Atlanta
Posts: 15
My Ride: 323i
For my calculations from the last couple of tanks I reset the odometer after filling up and when I refilled I divided the miles travelled by the amount of petrol I put in. I guess I could check for air leaks, I don't know how to check for o2 sensors, but they were changes within the last 20k. Again no codes or shadow codes on the pasoft. It just seems like the car is a little sluggish compared to my turbo audi which gets about 22-23 mpg. Perhaps thats because there are less hp in the e46, but averaging 250 mile range per tank or 15-16 mpg seems a bit low.
yappering is offline   Reply With Quote
Old 01-01-2013, 11:28 AM   #38
jfoj
Registered User
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 9,523
My Ride: '06 330CiC, '03 M5
The temp gauge in these cars is also for entertainment to some extent.

The gauge will stay at 12 o'clock over a 50F range!!!!

You need to access the Hidden OBC menu, 3rd link in my signature, and display the coolant temp on your OBC display. Normal temp is 90-95C, anything lower in town or at idle is a bad stat.

DISA not working also impacts mileage a bit was well, first link in my signature. VANOS seals leaking can also impact performance and mileage as well.

But the first thing to do it check coolant temp, then change gas station and brand. What EVERYONE needs to realize is the issue if more than just the fuel mixture, it is also a function of how well the pump is calibrated as well. You NEED to pay attention to the state calibration stickers on the pumps. If the date is more than 1 year old, I would be checking for a station with newer calibration stamps.

Winter blend fuels are also and Ethanol percentages are also a factor. FYI there is a push to consider going to 15% Ethanol, not sure it has been approved yet, but Ethanol blend percentage is not closely regulated and you would be surprised what the percentage you actually end up with may be!!
__________________
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 online now   Reply With Quote
Old 01-01-2013, 10:14 PM   #39
HacksawMark
OEM ///Member
 
HacksawMark's Avatar
 
Join Date: Oct 2012
Location: Portland, OR
Posts: 1,101
My Ride: 2014 Subaru XV
Quote:
Originally Posted by yappering View Post
Last tank I got about 16 mpg. 250 miles for a tank of about 15.4 gal. No check engine lights are on, no misfires. Used PA Soft and did not pull any codes. I do mostly city driving with a fair amount of stop and go, but I am not slamming on the throttle and I do some highway driving. I have a stick shift 323i. The temperature gauge gets right to the middle when the car warms up. I notice that the mpg indicator flies down to 12 mpg with the slightest application of throttle. For example if I am coming out of a rolling stop and am in first or second gear, it will hit 12 mpg even if I slowly accelerate to 30 mph. Additionally, if I am going down a gradient, such a parking garage and the car is in gear and I am applying a small amount of throttle, the mpg indicator flies to 12 mpg. Any thoughts?
Quote:
Originally Posted by yappering View Post
For my calculations from the last couple of tanks I reset the odometer after filling up and when I refilled I divided the miles travelled by the amount of petrol I put in. I guess I could check for air leaks, I don't know how to check for o2 sensors, but they were changes within the last 20k. Again no codes or shadow codes on the pasoft. It just seems like the car is a little sluggish compared to my turbo audi which gets about 22-23 mpg. Perhaps thats because there are less hp in the e46, but averaging 250 mile range per tank or 15-16 mpg seems a bit low.
If you do a lot of stop-n-go driving, keep in mind the engine is getting zero mpg while at a stop light. I would venture to say that you're getting about you should be getting for your driving environment. Are there ways to improve your mpg? Maybe. When I do in town driving, I shift to the next gear as soon as possible, many times going from 3rd to 5th gear no later then 40 mph.
HacksawMark is offline   Reply With Quote
Old 01-01-2013, 10:26 PM   #40
jfoj
Registered User
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 9,523
My Ride: '06 330CiC, '03 M5
Quote:
Originally Posted by hacksawmark View Post
If you do a lot of stop-n-go driving, keep in mind the engine is getting zero mpg while at a stop light.
+1, someone understands the concept, no miles and using fuel, well you get idea.

Quote:
Originally Posted by hacksawmark View Post
When I do in town driving, I shift to the next gear as soon as possible, many times going from 3rd to 5th gear no later then 40 mph.
Funny, on my M5, mainly because I am lazy, many times I start in 2nd gear and just use the even gears, I turn my 6 speed into a 3 speed as I get tired of rowing the boat!

First thing to do on all of these cars is to bring up the Hidden OBC Menu and monitor the coolant temperature. You should quickly get to about 90C and run between 88-93C consistently unless you lay into the throttle hard and trigger the electric thermostat element to drop the coolant temp.
__________________
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 online now   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 08:37 AM.


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