coolant level keeps dropping

007_e350 · 03-25-2015, 11:17 AM

Hey folks, any idea why my coolant level is dropping consistently but not to the level where it would throw the light ... dealership replaced waterpump saying it was leaking but now looks like something else is leaking too but not all the way... coolant is still greeny/ bluish so i hope its not mixing with oil or it would be milky right... anyone else experienced coolant leaks and knows where to look besides obvious hoses

Hoooper · 03-25-2015, 11:50 AM

Egr cooler would be a common spot. Not easy to just check though since normally they seem to leak inside the cooler and if its a small leak you probably wouldn't get enough steam out the exhaust to notice

kbsilver · 03-25-2015, 12:47 PM

Are you sure it's actually leaking? You should only fill to the MIN level when the engine is cold. Any attempt to fill more than that will only result in the system burping the excess coolant out the overflow when it heats up real good.

My issue is power steering fluid is disappearing. Nothing visible anywhere, dealer checked for leaks and none found, yet I need to add about 1/2 cup every year.

007_e350 · 03-25-2015, 12:59 PM

Quote:

Originally Posted by Hoooper

Egr cooler would be a common spot. Not easy to just check though since normally they seem to leak inside the cooler and if its a small leak you probably wouldn't get enough steam out the exhaust to notice

I'm so getting this damn EGR sh** out once warranty's done..

007_e350 · 03-25-2015, 01:01 PM

Quote:

Originally Posted by kbsilver

Are you sure it's actually leaking? You should only fill to the MIN level when the engine is cold. Any attempt to fill more than that will only result in the system burping the excess coolant out the overflow when it heats up real good.

My issue is power steering fluid is disappearing. Nothing visible anywhere, dealer checked for leaks and none found, yet I need to add about 1/2 cup every year.

i filled to the point where its under max and u cant read min carved, now its gotten under min again, shd stay over min

also last time it took abt 16 ounces roughly, which seemed high

BB_cuda · 03-25-2015, 01:21 PM

Hooper and I aren't saying that it for sure is your EGR cooler but it should be an easy thing to rule out. If you're a wrench turner, temporarily removing the EGR cooler isn't real difficult but you will lose even more coolant. My thought was to look for evidence of the blue coolant in the cooler where only exhaust gases should be passing through (at the gas inlet or outlet).

If you're under warranty, dealer should do this without a fuss. Maybe you should leave cooler alone now that I think as they might blame you for messing with cooler causing it to have internal water leakage.

There is another quite recent thread where guy was seeing white smoke coming out his tail pipe and in the end, it was the cooler.

007_e350 · 03-25-2015, 02:23 PM

Quote:

Originally Posted by BB_cuda

Hooper and I aren't saying that it for sure is your EGR cooler but it should be an easy thing to rule out. If you're a wrench turner, temporarily removing the EGR cooler isn't real difficult but you will lose even more coolant. My thought was to look for evidence of the blue coolant in the cooler where only exhaust gases should be passing through (at the gas inlet or outlet).

If you're under warranty, dealer should do this without a fuss. Maybe you should leave cooler alone now that I think as they might blame you for messing with cooler causing it to have internal water leakage.

There is another quite recent thread where guy was seeing white smoke coming out his tail pipe and in the end, it was the cooler.

well, they pressure tested the cooling system, shouldn't that expose a leak ? unless EGR shuts off the path which I doubt

BB_cuda · 03-25-2015, 08:13 PM

Did coolant level drop from pressure test? If EGR leak, you wouldn't necessarily see water externally. It's an internal leak into the gas tract of cooler. But that is IF the cooler is the culprit.

AYEDEE · 03-25-2015, 08:40 PM

Had same issue. Kept popping up low.coolant every month. Turned out to be a dying water pump /heater valve

BB_cuda · 03-26-2015, 03:35 PM

http://www.e90post.com/forums/showthread.php?t=1104253

This was the thread that I mentioned in post #6.

Hoooper · 03-26-2015, 04:25 PM

Quote:

Originally Posted by AYEDEE

Had same issue. Kept popping up low.coolant every month. Turned out to be a dying water pump /heater valve

But where was it going? Was the dying pump or valve leaking?

Roadrunner143 · 03-26-2015, 10:18 PM

Got the low level light a few times recently. I kept filling up and then brought it to the dealer. Turned out to be the auxiliary radiator (not the main one). Fixed the leak.

POBEP · 01-01-2021, 09:55 PM

Quote:

Originally Posted by kbsilver

You should only fill to the MIN level when the engine is cold. Any attempt to fill more than that will only result in the system burping the excess coolant out the overflow when it heats up real good.

kbsilver - thanks for the tip!

I believe I have "imaginary" coolant loss:
1K miles since thermostat(s) and coolant replacement I noticed that coolant level dropped to MIN mark when cold.
I topped it off to MAX, checked 3K miles later - again at MIN mark.

I just noticed
- that MIN mark cold fill level is clearly stated on the expansion tank.
- clear evidence of excess fluid being pushed out through the vent valve.

Should of read the manual.

Persian Whisperjet · 01-07-2021, 12:30 PM

I replaced the water pump to get after a leak but it persists. I now speculate that it's the goofy plastic cap on the water pump that used to feed the EGR block off. Fortunately AA Rod has produced nice billet ones, the pump is just tricky to get at.

Chief Orman · 04-21-2021, 09:28 PM

Quote:

Originally Posted by Persian Whisperjet

I replaced the water pump to get after a leak but it persists. I now speculate that it's the goofy plastic cap on the water pump that used to feed the EGR block off. Fortunately AA Rod has produced nice billet ones, the pump is just tricky to get at.

Just replaced mine...problem solved

03-25-2015, 11:17 AM	#1
007_e350 Lieutenant Colonel 230 Rep 1,909 Posts Drives: 335i 2008 MHD'd / x5d E70 Join Date: May 2013 Location: left lane iTrader: (3)	coolant level keeps dropping Hey folks, any idea why my coolant level is dropping consistently but not to the level where it would throw the light ... dealership replaced waterpump saying it was leaking but now looks like something else is leaking too but not all the way... coolant is still greeny/ bluish so i hope its not mixing with oil or it would be milky right... anyone else experienced coolant leaks and knows where to look besides obvious hoses __________________ Mods: 7" VRSF FMIC, Forge DVs, RB PCV, BMS Oil Cooler, VRSF DPs, MHD, JB4g5, OFT DIYs: Walnut blasting : Trans Oil at 45k, w Filter at 65k : Diff Oil Flush @ 45k : WP&TS @ 69k : Alternator @ 79k --- E70d Alphabet Soup del 44.4k : JR Stg2.25 tune : Buzzken Catted Exhaust : Trans fluid drain/ fill (3 Qrts), both Diffs fluids flushed Wheels: Style 95s on PSSs (Sold): AG 359s on S04s : 162s on Blizzaks : Rohana RF1 Matt black
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03-25-2015, 11:50 AM	#2
Hoooper Colonel 213 Rep 2,210 Posts Drives: 335D Join Date: Jun 2013 Location: Petaluma, CA iTrader: (0)	Egr cooler would be a common spot. Not easy to just check though since normally they seem to leak inside the cooler and if its a small leak you probably wouldn't get enough steam out the exhaust to notice Last edited by Hoooper; 03-25-2015 at 11:55 AM..
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03-25-2015, 12:47 PM	#3
kbsilver Captain 143 Rep 631 Posts Drives: 340GT & '22 eDrive40 Join Date: Jan 2012 Location: North Jersey iTrader: (0)	Are you sure it's actually leaking? You should only fill to the MIN level when the engine is cold. Any attempt to fill more than that will only result in the system burping the excess coolant out the overflow when it heats up real good. My issue is power steering fluid is disappearing. Nothing visible anywhere, dealer checked for leaks and none found, yet I need to add about 1/2 cup every year.
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03-25-2015, 08:13 PM	#8
BB_cuda Brigadier General 796 Rep 3,572 Posts Drives: 2011 335D Msport, 2013 X5D Join Date: Nov 2011 Location: Clear Lake, Texas iTrader: (0)	Did coolant level drop from pressure test? If EGR leak, you wouldn't necessarily see water externally. It's an internal leak into the gas tract of cooler. But that is IF the cooler is the culprit.
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03-25-2015, 08:40 PM	#9
AYEDEE Captain 58 Rep 936 Posts Drives: 3 Series BMW Join Date: Oct 2013 Location: NSW iTrader: (0)	Had same issue. Kept popping up low.coolant every month. Turned out to be a dying water pump /heater valve
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03-25-2015, 01:21 PM	#6
BB_cuda Brigadier General 796 Rep 3,572 Posts Drives: 2011 335D Msport, 2013 X5D Join Date: Nov 2011 Location: Clear Lake, Texas iTrader: (0)	Hooper and I aren't saying that it for sure is your EGR cooler but it should be an easy thing to rule out. If you're a wrench turner, temporarily removing the EGR cooler isn't real difficult but you will lose even more coolant. My thought was to look for evidence of the blue coolant in the cooler where only exhaust gases should be passing through (at the gas inlet or outlet). If you're under warranty, dealer should do this without a fuss. Maybe you should leave cooler alone now that I think as they might blame you for messing with cooler causing it to have internal water leakage. There is another quite recent thread where guy was seeing white smoke coming out his tail pipe and in the end, it was the cooler.
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03-26-2015, 03:35 PM	#10
BB_cuda Brigadier General 796 Rep 3,572 Posts Drives: 2011 335D Msport, 2013 X5D Join Date: Nov 2011 Location: Clear Lake, Texas iTrader: (0)	http://www.e90post.com/forums/showthread.php?t=1104253 This was the thread that I mentioned in post #6.
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03-26-2015, 10:18 PM	#12
Roadrunner143 Enlisted Member 6 Rep 42 Posts Drives: 335d Join Date: Dec 2012 Location: MTL, Canada iTrader: (0)	Got the low level light a few times recently. I kept filling up and then brought it to the dealer. Turned out to be the auxiliary radiator (not the main one). Fixed the leak.
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01-07-2021, 12:30 PM	#14
Persian Whisperjet Kind of a Big Deal 171 Rep 857 Posts Drives: 2011 335d Join Date: Dec 2012 Location: Washington, D.C. iTrader: (0)	I replaced the water pump to get after a leak but it persists. I now speculate that it's the goofy plastic cap on the water pump that used to feed the EGR block off. Fortunately AA Rod has produced nice billet ones, the pump is just tricky to get at. __________________
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