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E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

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  #1  
Old 07-04-2011, 12:25 AM
zoccer22 zoccer22 is offline
zoccer22
Location: North Las Vegas
 
Join Date: Jul 2011
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Mein Auto: 2002 BMW 530i Sport 5SPD
Coolant overflow tank not emptying

I am a new member of the forum but have been relying on the information here since I got my 02 530i three years ago. It never fails that I can get what I am looking for.
My car is a 2002 530i Sport. (Radiator only 8 months old)

I have an issue that I cannot seem to find a solution to.

My fan (attached to water pump) recently broke a blade off, and I had to drive it for the rest of the day before I was able to replace it. It gave the car some bad jitters but no other problems were evident. Replaced the fan and the fan clutch. I check the coolant once everything was good and done, and noticed it only filled up and was not emptying. And that it was a steady drip coming from the hole in the top instead of the normal stream. So I did the following:
Bled the system of air for roughly 2 hours to make sure there was no air. Followed the instructions I found here on the forum. Still it was only a drip going in and the tank was overflowing because it was not emptying. So I checked all the hoses and made sure they were connected tightly and washed everything out and checked for leaks a couple hours later after the car cooled. No leaks in the system. Replaced the Water Pump, thinking the fan could have jostled it and broke it. Still having the same issue. The radiator and hoses are less than a year old (8 months), the water pump is brand new. And I partially debunked that it could be from a clog. I bled the heater as well. The heater will circulate and pull from the coolant tank, but once the heater is off the coolant tank starts filling up and does not empty.

Couple Notes:
I also started to notice my AC only works when I am driving, and turns hot when I sit. And another side note as well, the fan clutch is engaging while idling and revving. It will disengage once I hit about 25 MPH. And the temp sensor never goes over half. And no check engine codes have fired.

I am not sure what this can be. I wanted to ask around and see before I started replacing the thermostat. Just to make sure it wasn't another issue that some one had experienced.
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  #2  
Old 07-04-2011, 07:27 AM
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QSilver7 QSilver7 is offline
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Im somewhat confused about your cooling system and if there's really an issue. First, it is not an "overflow" tank...it is an EXPANSION tank.

How are you "observing" that the tank is not filling up? When the engine has cooled...open the expansion tank and make sure that the needle rises to the top of the neck (as explained in the owners manual and by the icon embossed into the expansion tank)...then screw the lid on. From what you wrote...I'll assume that the air has been bled from the system (unless you are getting a warning). Are you getting a warning light? Is the LOW COOLANT or CHECK COOLANT warning light illuminated?

As far as the diminished cooling from the AC when the car is stationary or in stop-n-go-traffic...you need to check to see if your aux fan is turning on. This is the fan in FRONT of the radiator which you can see when you're standing in front of the car looking thru the kidney grills. You should be able to find info about the aux fan by doing a simple search...this topic has been discussed pretty frequently of late...you probably could even do a google search (BMW aux fan) and get plenty of results.
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2006 E53 X5 4.4i (Sterling Gray) 12/05 mfg date <<~>> 97 740iL (Arctic Silver) 3/97 mfg date
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99 540iT (Orient Blue) <<~>> 95 525IT (Alpine White)
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Last edited by QSilver7; 07-04-2011 at 07:33 AM.
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  #3  
Old 07-04-2011, 08:58 AM
zoccer22 zoccer22 is offline
zoccer22
Location: North Las Vegas
 
Join Date: Jul 2011
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Mein Auto: 2002 BMW 530i Sport 5SPD
Thanks for the fast reply.

First as far as observing the flow of coolant in the expansion tank. I was following directions given to me by my dealer and also printed on the BMW anitfreeze bottle I purchased from them. Which is the following: (After reading in my manual I now realize its a contradiction)
Slowly unscrew the coolant expansion tank cap
Check the level of coolant and add as needed
Start the Engine and let the engine reach normal operating temperature. Keep watching the expansion tank and make sure it never gets emptied of coolant.
Keep filling to fill line until a steady flow of coolant is emptying into the tank. (No air in the stream)
Replace cap and turn off the car. Let the car cool down and ensure the tank is filled properly.

This is what I had been doing for the last 3 years with no issues. There was always plenty of suction to empty the tank. But as stated above I realize now that my manual says DO NOT fill the tank while engine is hot. So thats my mistake, but still find it odd that its not working the way it used to.

So as for the problem that I think I have is I will check the expansion tank and it will be at the correct level. I will drive around for about 20-25 minutes, and let the car cool down and check it again. The level is now almost to the brim, and almost overflowing. To get it to return to normal I turn the key to acc and turn the heater on full blast to circulate it through the heater core (I believe thats correct, please correct if I am wrong).

As of right now, I am getting no warnings of any sort. No Low coolant, check engine soon, or overheating. The car runs perfectly normal from what I can tell, but it worries me that the tank has more coolant in it after I drive it and let it cool. I rarely have to drive more than 30 minutes, but I am also afraid to, in that too much pressure might build up.
Hopefully all that makes sense. I am mainly going by what my dealer told me about a year ago when I was looking to replace the radiator.

For my AC, thanks for the tip. I noticed this morning that the fan is not coming on nearly as much as I used to hear it. And sure enough it wasn't working hardly at all, so I know I that needs to be replaced. Thanks again.

Last edited by zoccer22; 07-04-2011 at 09:03 AM.
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  #4  
Old 07-04-2011, 09:18 AM
pleiades pleiades is offline
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zoccer22, the instructions you cite sound like something someone would follow when changing out the coolant with new and bleeding the system. That is not a procedure for routine everyday maintenance. Your expansion tank has a built in level bar that floats up through the top of the mouth when the cap is open. When the car is cold, the tip of the level bar should be flush with the top of the exp. tank mouth. When the coolant is still warm (and expanded), the level bar should be about an inch above the top edge of the tank mouth.

Your car has a "closed" cooling system. If it has been properly filled, you do not need to be adding any more coolant to it. If you have been adding coolant on a regular basis, you have a leak somewhere.
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  #5  
Old 07-04-2011, 09:31 AM
zoccer22 zoccer22 is offline
zoccer22
Location: North Las Vegas
 
Join Date: Jul 2011
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Mein Auto: 2002 BMW 530i Sport 5SPD
That would make sense why I was told that. Since I was replacing the radiator and changing the coolant. Thanks. I will bleed one final time and leave it be and just monitor for any issues. Thanks again for all the help. Ill post more if something goes wrong. Thanks
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  #6  
Old 07-04-2011, 09:38 AM
pleiades pleiades is offline
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I won't go into here but if you search the forum you'll find threads on detailed bleeding procedure. The real purpose is to get all air out of the system and the bleeder screws on the t-stat housing and expansion tank have a role to play.
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  #7  
Old 07-04-2011, 01:16 PM
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QSilver7 QSilver7 is offline
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I still don't understand why you are "bleeding" the system. As I wrote before, as pleades said, and as it is written in the owners manual and embossed on the expansion tank...fill the expansion tank until the red float rises to the top. Then CLOSE the lid!

You don't need to continue to bleed the system if there's no air trapped inside...and you'd know that from filling, then getting a warning that the coolant was low. And the instructions on the coolant bottle is written for multiple BMW models...there are some BMWs that still have overflow tanks, some have clear expansion tanks, and some have black expansion tanks w/float that bobs up to the top...the instructions for what's appropriate for your car is written in its owners manual.

Could part of your confusion be that your expansion tank is missing its pop-up float??? And if you overfill the system...when the coolant expands...the overfill will be released form the cap...it is designed to release pressure if it becomes too high.




(image from TIS & taken from rdl's reply in a coolant thread)
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Q {BMW CCA Member #191509}
2006 E53 X5 4.4i (Sterling Gray) 12/05 mfg date <<~>> 97 740iL (Arctic Silver) 3/97 mfg date
(SOLD)
99 540iT (Orient Blue) <<~>> 95 525IT (Alpine White)
91 735iL (Schwarz Black) <<~>> 85 325e (Bronzit)

http://imageshack.com/scaled/grid240/822/e38e532ndsigpic.jpg

Last edited by QSilver7; 07-04-2011 at 01:28 PM.
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  #8  
Old 07-04-2011, 09:50 PM
zoccer22 zoccer22 is offline
zoccer22
Location: North Las Vegas
 
Join Date: Jul 2011
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Mein Auto: 2002 BMW 530i Sport 5SPD
I was able to get the aux fan working again, and now I don't have issues with the fan clutch kicking in or any problems with the AC. Thanks for the tip.

As for the coolant, I followed your instructions (QSilver7) on checking the level when the car was cold (hadn't been driven since yesterday). The level was about an inch and a half higher than it should have been so I siphoned some of the coolant out until it was properly filled. Drove the car around for about an hour and noticed a smell of coolant when I parked. I looked around and couldn't find any indication of leaking so I washed the engine down to erase any previous marks so I can better tell where the leak is, if any. So I let it cool down for awhile and checked the level again roughly 5 hours later (the temp needle was pegged at the bottom blue area), and the level was again higher than it should be, about an inch and a half again. So again I siphoned out the excess and put the cap back on. I haven't checked it again since but did notice the smell again after driving it to work for about 30 minutes. So I am guessing I have a leak somewhere, and again I wasn't able to locate any indications of leaking. But why would the level still be higher? I double checked both times and even had a friend check me so I made sure it was filled right.

I am not getting any warning lights or errors. And there are no leaks reaching the ground after I have parked, so if it is a leak its getting burned off before its reaches the ground. But after washing it off and looking again I cannot seem to locate any leakage. But the thing that is not making sense, and it could be because I don't understand how the system works, is that I smell coolant and yet the tank is fuller than before. That doesn't seem to make sense why it would do that.

Could it be a blockage somewhere?

If you need more info let me know. The water pump was just replaced a week ago as well. The radiator is about 8 months old, as well as all the hoses. The only things that haven't been replaced yet are the expansion tank and thermostat.

Last edited by zoccer22; 07-04-2011 at 09:53 PM.
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  #9  
Old 07-05-2011, 01:51 PM
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QSilver7 QSilver7 is offline
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The next time you're driving around and "smell" coolant, pull over to a safe place, leave the engine running (w/tranny in park), open the hood and see if you see any spray or leak from the cooling system.

Also, feel around below the dash and the rear passenger floor pan for any wet/damp carpeting in the event that you have sprung a leak inside.

Or perhaps the "smell" of coolant is the OVERFILL being released from the expansion tank cap.

Quote:
Originally Posted by QSilver7
if you overfill the system...when the coolant expands...the overfill will be released form the cap...it is designed to release pressure if it becomes too high.
__________________
Q {BMW CCA Member #191509}
2006 E53 X5 4.4i (Sterling Gray) 12/05 mfg date <<~>> 97 740iL (Arctic Silver) 3/97 mfg date
(SOLD)
99 540iT (Orient Blue) <<~>> 95 525IT (Alpine White)
91 735iL (Schwarz Black) <<~>> 85 325e (Bronzit)

http://imageshack.com/scaled/grid240/822/e38e532ndsigpic.jpg
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  #10  
Old 07-05-2011, 07:26 PM
zoccer22 zoccer22 is offline
zoccer22
Location: North Las Vegas
 
Join Date: Jul 2011
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Mein Auto: 2002 BMW 530i Sport 5SPD
Okay. So started smelling coolant and checked under the hood, and sure enough its coming from the expansion tank cap. I let the car cool down again and checked the coolant level and it was again about 1.5 inches above full. I siphoned off the excess and put the cap back on. I am waiting for the car to cool down right now to check it again. But when I checked yesterday I had to siphon off excess coolant twice to get it back down to the full line. Still no warning lights. I will check again after the car cools and see if it reads over the full line or at the line. What could be causing the coolant to backup like that and keep coming out the cap. I checked twice to make sure it was at the full line yesterday and it still overflows.
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  #11  
Old 07-05-2011, 08:52 PM
pleiades pleiades is offline
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I missed where you said you actually bled the system properly.

Point the car uphill (or put the front on ramps), open the bleeder screws on the t-stat housing and the expansion tank and open the expansion tank cap; turn on the ignition (but not the engine), turn on the heater at highest temp setting with fan on low (you should hear the heater pump moving coolant). If you have air in the system chances are you'll see bubbling coolant from the t-stat housing bleeder first; when it's just coolant (no bubbles) close that screw off; repeat at exp. tank screw. If you need to add any coolant (low level stick) then is the time to do it. Close exp tank cap, drive the car around a bit and repeat if necessary.
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Old 07-05-2011, 09:12 PM
zoccer22 zoccer22 is offline
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Location: North Las Vegas
 
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Mein Auto: 2002 BMW 530i Sport 5SPD
Checked again now that the car is cooled. And still high coolant in the tank.

I will go ahead and bleed based your instructions (pleiades). And I will see if that resolves the issue. Thanks again.
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  #13  
Old 07-06-2011, 11:06 AM
stlbmw stlbmw is offline
stlbmw
Location: Missouri
 
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Mein Auto: 2002 745Li/1999 528i
Hey Zoccer22, I am having problems with my air co as well. Doesn't blow cold. What is the thought of the connection of this aux fan and the air co.
AND...how did you fix the aux fan. I'll assume it was not turning on ??
Any thought would be appreciated. I'm burning up on the way to work.

stlbmw
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  #14  
Old 07-06-2011, 10:55 PM
zoccer22 zoccer22 is offline
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Location: North Las Vegas
 
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Mein Auto: 2002 BMW 530i Sport 5SPD
Quote:
Originally Posted by stlbmw View Post
Hey Zoccer22, I am having problems with my air co as well. Doesn't blow cold. What is the thought of the connection of this aux fan and the air co.
AND...how did you fix the aux fan. I'll assume it was not turning on ??
Any thought would be appreciated. I'm burning up on the way to work.

stlbmw
Just as a note my AC was only hot when I was sitting, it cools just fine while in motion. Its possible you may have a different problem if yours is not cooling at all.

From research after given the tip by QSilver7, The connection is the aux fan cools the AC condenser. According to other threads the fan should always be on when the AC is active. If the AC is off then the fan only turns on at particular temps based on a temp sensor on a radiator hose on the passenger side of the radiator under the expansion tank. Here is one of the links to that info.
http://forums.bimmerforums.com/forum...d.php?t=605750

But for the aux fan (since you said it wasn't working) my fix was really easy as it turns out. My fuse was popped, and thats why it wasn't working. Here is a link that I used to track down how to take it apart and find the connections. I am by no means an expert, so I cannot offer any real information other than this link.

http://www.bimmerfest.com/forums/sho...d.php?t=205728

However on this forum there are many threads that can offer some insight to the resistor that might cause an issue, and how to remove/replace the whole fan and motor.

Here is a link i found in another thread for the resistor, and the fan connection as well.

http://www.howtopdf.com/?zx1OfYIv

Hopefully this helps. If your problem is indeed your aux fan.

Last edited by zoccer22; 07-06-2011 at 11:03 PM.
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  #15  
Old 07-06-2011, 11:08 PM
zoccer22 zoccer22 is offline
zoccer22
Location: North Las Vegas
 
Join Date: Jul 2011
Posts: 8
Mein Auto: 2002 BMW 530i Sport 5SPD
Quote:
Originally Posted by pleiades View Post
I missed where you said you actually bled the system properly.

Point the car uphill (or put the front on ramps), open the bleeder screws on the t-stat housing and the expansion tank and open the expansion tank cap; turn on the ignition (but not the engine), turn on the heater at highest temp setting with fan on low (you should hear the heater pump moving coolant). If you have air in the system chances are you'll see bubbling coolant from the t-stat housing bleeder first; when it's just coolant (no bubbles) close that screw off; repeat at exp. tank screw. If you need to add any coolant (low level stick) then is the time to do it. Close exp tank cap, drive the car around a bit and repeat if necessary.
Okay. Spent a good 2 hours bleeding the system and there was some air and foam that came out after each drive around. I haven't smelled any coolant since, but i will keep an eye on it to see if it stops coming out the cap. Thanks again for the help, and hopefully my problems end here.
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  #16  
Old 07-07-2011, 08:27 AM
stlbmw stlbmw is offline
stlbmw
Location: Missouri
 
Join Date: Dec 2008
Posts: 225
Mein Auto: 2002 745Li/1999 528i
Quote:
Originally Posted by zoccer22 View Post
Just as a note my AC was only hot when I was sitting, it cools just fine while in motion. Its possible you may have a different problem if yours is not cooling at all.

From research after given the tip by QSilver7, The connection is the aux fan cools the AC condenser. According to other threads the fan should always be on when the AC is active. If the AC is off then the fan only turns on at particular temps based on a temp sensor on a radiator hose on the passenger side of the radiator under the expansion tank. Here is one of the links to that info.
http://forums.bimmerforums.com/forum...d.php?t=605750

But for the aux fan (since you said it wasn't working) my fix was really easy as it turns out. My fuse was popped, and thats why it wasn't working. Here is a link that I used to track down how to take it apart and find the connections. I am by no means an expert, so I cannot offer any real information other than this link.

http://www.bimmerfest.com/forums/sho...d.php?t=205728

However on this forum there are many threads that can offer some insight to the resistor that might cause an issue, and how to remove/replace the whole fan and motor.

Here is a link i found in another thread for the resistor, and the fan connection as well.

http://www.howtopdf.com/?zx1OfYIv

Hopefully this helps. If your problem is indeed your aux fan.
Thanks for the tips and your time

appreciate it !

stlbmw
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