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 06-22-2015, 09:46 AM   #1
MachtSchnell
Registered User
 
Join Date: Jun 2015
Location: United States
Posts: 8
My Ride: 2002 330Ci
Intermittent coolant light

Here's the situation, I drive a 2002 330Ci, 135k miles. A week ago the "Service Engine Soon" light lit up. Went to the dealer (on 6/19) and they replaced the thermostat. Drove it off the lot, and started loosing coolant, took it back and what a surprise, the expansion tank had to be replaced. Expansion tank was replaced, drove it home.

Coolant light came on again, I topped off the coolant with 50/50 OEM/water (on 6/21). Now, the coolant light is being very sporadic. On the 10 mile commute to work this morning (mostly highway), the light lit up then went off 3 or 4 times, on for 30 sec to a few minutes at a time.

Engine temp is normal. When I spoke to the dealer prior to topping off coolant, he said that with the two repairs, there may be air bubbles confusing the sensors. But I'm unsure how long to wait.

When I start the car, the light is off, but after driving it starts going on and off again. No significant moisture under the car after being parked overnight.

Any thoughts/recommendations?
MachtSchnell is offline   Reply With Quote
Ads by Google

Guests, get your FREE E46Fanatics.com membership to remove this ad.
Old 06-22-2015, 09:55 AM   #2
jfoj
OEM ///Member
 
Join Date: Nov 2009
Location: Fairfax, VA USA
Posts: 22,858
My Ride: 330CiC, M5, X5, E93
Could be air in the system, could be a slow leak, could be a flaky coolant level sensor.

Check very carefully around the lower radiator hose, there is a temperature sensor in this hose that is for the radiator outlet temperature. These leak all the time when the car is off and cool. If there is any sign of moisture or white staining around the switch or on the lower engine cover, replace the O-ring for he switch.

Very easy to change, no tools required, do it with a cool engine and leave the expansion tank cap on and you may loose only 1 cup of coolant.

See the last line in my signature for the O-ring part number, do not try to get the dealer to look up the part number, they ONLY sell the sensor with the O-ring, they do not have a separate listing for the O-ring. These O-rings need to be changed every 5 years otherwise you will have issues.
__________________
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 06-22-2015, 10:53 AM   #3
clabcon
Registered User
 
Join Date: Aug 2011
Location: London, UK
Posts: 308
My Ride: e46 330 Ci
Unfortunately I purchased all of the remaining O-ring stock and you can only buy them from me for $9.95 + SHIPPING.
clabcon is offline   Reply With Quote
Old 06-22-2015, 12:55 PM   #4
MachtSchnell
Registered User
 
Join Date: Jun 2015
Location: United States
Posts: 8
My Ride: 2002 330Ci
Quote:
Originally Posted by clabcon View Post
Unfortunately I purchased all of the remaining O-ring stock and you can only buy them from me for $9.95 + SHIPPING.
No thanks. I hope not everyone on this forum is just trying to sell parts.
MachtSchnell is offline   Reply With Quote
Old 06-22-2015, 03:51 PM   #5
clabcon
Registered User
 
Join Date: Aug 2011
Location: London, UK
Posts: 308
My Ride: e46 330 Ci
I wasn't being serious. Just lube it up with coolant before installation to get a good seal and avoid tearing.
clabcon is offline   Reply With Quote
Old 06-22-2015, 04:04 PM   #6
dmax
Registered User
 
dmax's Avatar
 
Join Date: Aug 2006
Location: NJ
Posts: 23,702
My Ride: '99 328i 300K miles
In a.m., when cool, fill ET to between min and max on the ET's stick...do not fill to maximum, as there is no 'over maximum' indicator, but overfill, you'll have a big problem. It could still just be low coolant being indicated by air bubbles.

Read Mango's cooling thread for bleeding instructions...in it, I posted an alternative method that might work for you too.

Start with bleeding. If that isn't it, you do, as mentioned, probably have another leak letting air in and coolant out...a double problem!

Clean things up and see where, if anywhere, you're loosing coolant. Look on the underskirt too. It could be minimal, but dripping on it and blowing off when you drive so you might not notice it on the garage floor or where you park.

If you EVER begin to overheat, though, pull over, turn car off, and get it towed...or you'll suffer the fate others have here...not infrequently.

hth
__________________
See me in June!
Ha! Ridgehill, Yonkers, June 8, 8 p.m. & Broadway Comedy Club, Sat., June 10, 6 p.m., hosting at the Comedy Cove, Springfield, NJ, June 16 & 17 for Joe DeVito, 9 p.m.
See Facebook for other shows and PM me if you can make one.


Please view this vid so it looks like I'm popular. Please! https://youtu.be/995gLmVEVZk

dmax on Facebook

Mangofy your E46!
dmax is offline   Reply With Quote
Old 06-22-2015, 04:17 PM   #7
MachtSchnell
Registered User
 
Join Date: Jun 2015
Location: United States
Posts: 8
My Ride: 2002 330Ci
I'll check it in the AM. If anything, I'm worried I may have overfilled the coolant a bit. The stick was below the cap and I added 3 cups of the 50/50 mix. I'll check for leaks in the parking garage after work and tomorrow morning in the driveway.

Is there a way to remove some of the coolant without bleeding the entire system?
MachtSchnell is offline   Reply With Quote
Old 06-22-2015, 04:55 PM   #8
clabcon
Registered User
 
Join Date: Aug 2011
Location: London, UK
Posts: 308
My Ride: e46 330 Ci
Quote:
Originally Posted by MachtSchnell View Post
I'll check it in the AM. If anything, I'm worried I may have overfilled the coolant a bit. The stick was below the cap and I added 3 cups of the 50/50 mix. I'll check for leaks in the parking garage after work and tomorrow morning in the driveway.

Is there a way to remove some of the coolant without bleeding the entire system?
I personally fill the expansion tank to the brim whilst bleeding, then use the body of a fluid transfer pump to bring the top of the float level with the expansion tank neck threads i.e. minimum when cold. Maybe a touch less if below 20 deg C ambient.
clabcon is offline   Reply With Quote
Old 06-22-2015, 06:28 PM   #9
MachtSchnell
Registered User
 
Join Date: Jun 2015
Location: United States
Posts: 8
My Ride: 2002 330Ci
Bad news this afternoon:

Coolant light lit up after about 15 minutes of driving. There appears to be a leak as well, but level was not low. I parked outside a store for 5 minutes after work and there was already some moisture (felt, smelled like coolant). Popped the hood after the commute this afternoon, and there was coolant bubbling/seeping through the cap. The signature white residue was there.

Also, red oil light flickered two or three times on the 5 minute drive from store to home.

Taking the car to the shop first thing in the AM.
MachtSchnell is offline   Reply With Quote
Old 06-22-2015, 07:01 PM   #10
BaliDawg
Keepin' it real stock
 
Join Date: Aug 2012
Location: Riverside, CA
Posts: 5,524
My Ride: E24 E32 E46 E39 E84
I thought that was funny!

You'd be like the Willie (of air distribution manifold o-ring fame) of LRH o-rings. LOL
__________________
///Mmmmmm...
BaliDawg is offline   Reply With Quote
Old 06-22-2015, 07:10 PM   #11
BaliDawg
Keepin' it real stock
 
Join Date: Aug 2012
Location: Riverside, CA
Posts: 5,524
My Ride: E24 E32 E46 E39 E84
The intermittant low coolant light is very common, especially when you have recently worked on the cooling system and lost some coolant, then refilled.

You check the level when cold and it is normal, then drive it for 5-10 minutes and the low coolant light comes on (when the thermostat opens). Then hours later after the engine is cold again you check it and the level is normal and say, "WTF?!"

You cannot, and must never, check the coolant level when hot. Yet everytime you check it when cold the level is normal.

The cause is trapped air in the system. Do a proper bleed and that solves it.
__________________
///Mmmmmm...
BaliDawg is offline   Reply With Quote
Old 06-22-2015, 07:33 PM   #12
MachtSchnell
Registered User
 
Join Date: Jun 2015
Location: United States
Posts: 8
My Ride: 2002 330Ci
Quote:
Originally Posted by clabcon View Post
I wasn't being serious. Just lube it up with coolant before installation to get a good seal and avoid tearing.
I appreciate the joke now! In the midst of repeat trips to the shop I lost my sense of humor.
MachtSchnell is offline   Reply With Quote
Old 06-23-2015, 09:23 AM   #13
MachtSchnell
Registered User
 
Join Date: Jun 2015
Location: United States
Posts: 8
My Ride: 2002 330Ci
Coolant and oil were low last night. Added 2-3 cups coolant to bring it to proper level and added about a half liter of oil. Dropped the car off and hitched a ride to the office this morning. Hope to have it back today.
MachtSchnell is offline   Reply With Quote
Old 06-23-2015, 02:32 PM   #14
MachtSchnell
Registered User
 
Join Date: Jun 2015
Location: United States
Posts: 8
My Ride: 2002 330Ci
Dealer said it was a bleeder valve on a radiator hose. Thankfully, as of now, sounds like it's relatively cheap and not serious. No mention of oil light.
MachtSchnell is offline   Reply With Quote
Reply

Tags
coolant, coolant light, coolant light help, expansion tank

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 01:40 AM.


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