Where is my coolant going?

P2 · 11-10-2012, 09:46 AM

325 06 71000miles.

I received a low coolant warning. It was low and I added 3.5 cups of 50/50 BMW/Distilled Water. 200 miles later, it showed just a little low. I added 1/3 cup to bring back up. All levels taken cold.

I see no leaks, no white smoke and the system is under pressure when I open the cap.

It was low one other time in 2007 and 13000 miles.

What do you guys think. Should I be concerned?

gpb · 11-10-2012, 10:37 AM

I'd check the oil for milkiness and keep an eye on the coolant level. Could also be a pinhole leak that only occurs at high temps or something. Do you have any coolant smell in the cabin and/or a higher amount of filming on the inside glass?

Tough to figure out the cause unless you can find where the coolant is going.

Efthreeoh · 11-10-2012, 12:23 PM

I wouldn't be concerned at all. That's normal coolant loss. It depends on what the temp of the coolant was at 200 miles you added a bit more to top it off. Keep an eye on it and see what it does.

P2 · 11-10-2012, 01:12 PM

Quote:

Originally Posted by gpb

I'd check the oil for milkiness and keep an eye on the coolant level. Could also be a pinhole leak that only occurs at high temps or something. Do you have any coolant smell in the cabin and/or a higher amount of filming on the inside glass?

Tough to figure out the cause unless you can find where the coolant is going.

I think I'll get an oil change and to a Blackstone analysis. I'll be able to see the condition of the oil and Blackstone will show if any antifreeze is in there.

No smell. No abnormal filming (always some in any car with plastics).

P2 · 11-10-2012, 01:13 PM

Quote:

Originally Posted by Efthreeoh

I wouldn't be concerned at all. That's normal coolant loss. It depends on what the temp of the coolant was at 200 miles you added a bit more to top it off. Keep an eye on it and see what it does.

Thanks. I'll think I'll do an oil analysis for peace of mind.

mlifxs · 11-10-2012, 02:07 PM

Quote:

Originally Posted by Efthreeoh

I wouldn't be concerned at all. That's normal coolant loss. It depends on what the temp of the coolant was at 200 miles you added a bit more to top it off. Keep an eye on it and see what it does.

good advice

P2 · 11-10-2012, 03:11 PM

Quote:

Originally Posted by mlifxs

good advice

Ya. I probably need to take a deep breath

Efthreeoh · 11-18-2012, 06:14 AM

Quote:

Originally Posted by P2

Ya. I probably need to take a deep breath

I just did my 2nd 100,000 mile tuneup. I topped off all fluids. I had to add about 12 ounces of coolant and I probably checked it 25,000 miles ago. The stick was just at the minimum mark. It's not unusual to have to add coolant. The system is under pressure, some of it escapes over time as the system ages, the easier it is for coolant to escape.

AlanAZ · 11-18-2012, 11:12 AM

Quote:

Originally Posted by P2

I think I'll get an oil change and to a Blackstone analysis. I'll be able to see the condition of the oil and Blackstone will show if any antifreeze is in there.

I was concerned about my coolant loss after I bought mine, as my E46 used hardly any at all. I put in UV dye to look for a leak, replaced the coolant, had it pressure tested, and replaced the cap.

The thing that settled it for me was a Blackstone oil analysis that showed zero coolant in the oil. Well worth the ~$30. These engines lose coolant, I just top it up on a regular basis.

http://www.e90post.com/forums/showthread.php?t=446987

I've since then preemptively replaced the oil filter housing gasket to ensure no leak there.

http://www.e90post.com/forums/showthread.php?t=632565

11-10-2012, 09:46 AM	#1
P2 First Lieutenant 53 Rep 375 Posts Drives: 2023 i4 M-Sport eDrive 40 Join Date: Mar 2006 Location: NW Chicago Land iTrader: (0)	Where is my coolant going? 325 06 71000miles. I received a low coolant warning. It was low and I added 3.5 cups of 50/50 BMW/Distilled Water. 200 miles later, it showed just a little low. I added 1/3 cup to bring back up. All levels taken cold. I see no leaks, no white smoke and the system is under pressure when I open the cap. It was low one other time in 2007 and 13000 miles. What do you guys think. Should I be concerned?
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11-10-2012, 10:37 AM	#2
gpb First Lieutenant 5 Rep 393 Posts Drives: 335i Cabrio Join Date: Sep 2012 Location: Atlanta iTrader: (0)	I'd check the oil for milkiness and keep an eye on the coolant level. Could also be a pinhole leak that only occurs at high temps or something. Do you have any coolant smell in the cabin and/or a higher amount of filming on the inside glass? Tough to figure out the cause unless you can find where the coolant is going.
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11-10-2012, 12:23 PM	#3
Efthreeoh General 17278 Rep 18,720 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	I wouldn't be concerned at all. That's normal coolant loss. It depends on what the temp of the coolant was at 200 miles you added a bit more to top it off. Keep an eye on it and see what it does.
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