2007 650i Engine Coolant Leaking?

I first noticed in December 2012 that my coolant level was low because the warning light came on. Long story short I added 1/2 gallon of distilled water and the light has stayed off since.

Today I decided to check the level and the stick that bobs up in the water was not sticking out. So I added most of the remaining gallon of water to completely fill up the coolant tank.

I have to take it to be serviced for brake fluid so I guess I can ask about it then.

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In the meantime, any ideas on what could be happening?

I don't know that much about cars so anything I could say that would keep me from getting completely taken advantage of would be helpful since I'm taking it to the dealership ('cause they give me a loaner car and I'm a single guy without another ride).

Originally Posted by davidrhenley

I first noticed in December 2012 that my coolant level was low because the warning light came on. Long story short I added 1/2 gallon of distilled water and the light has stayed off since.

Today I decided to check the level and the stick that bobs up in the water was not sticking out. So I added most of the remaining gallon of water to completely fill up the coolant tank.

I have to take it to be serviced for brake fluid so I guess I can ask about it then.

--

In the meantime, any ideas on what could be happening?

I don't know that much about cars so anything I could say that would keep me from getting completely taken advantage of would be helpful since I'm taking it to the dealership ('cause they give me a loaner car and I'm a single guy without another ride).

Oh no. You may have the dreaded coolant pipe leak that has plagued the N62 engine. Do a search on this topic as it can be a main factor for such a large loss of coolant.

Check for leaks around your coolant expansion tank. That's typically the must likely source.

I just replaced mine over the weekend. It finally sprung a real leak after dripping slowly for a month.

Could be a simple leak from a hose, or the tanks.... or as bad as the transfer pipe, i would get it checked out, good luck!

You need to check a couple of places, some have been listed, but there is one not mentioned and is a common leak point. And a minor fix!

On the passenger side of the engine at the front, there is a lower radiator hose, in it is a sensor. The O-Ring fails and it could be leaking from there. The fact that yours is not coming out rapidly lends itself to a smaller leak point. If you take it to the dealer they will replace the entire hose and sensor for several hundred. But you can just buy an O-Ring from Home Depot and fix yourself.

http://www.bimmerfest.com/forums/sho...d.php?t=578644

If you are losing coolant, the expansion is most likely going to fail shortly! I would suggest changing the expansion tank, the bleed line, & the 0-ring for the coolant sensor. They can all be done within a hour. Overkill maybe, but the expansion tank will fail soon.

Good Luck!

While I was replacing my heater control valve I found this.





Sorry pics are low quality it was dark and I used my phone. Look at the shimmering areas that is coolant leaking. I have been topping off every 2 weeks.

I took apart my fire wall cover and this is the back side of the engine.
This is the back of intake manifold. You think the curse has hit ?
I hear it leaks from the front more often but how often from the rear?

Originally Posted by Nitrogen

While I was replacing my heater control valve I found this.

Attachment 361601

Attachment 361600

Sorry pics are low quality it was dark and I used my phone. Look at the shimmering areas that is coolant leaking. I have been topping off every 2 weeks.

I took apart my fire wall cover and this is the back side of the engine.
This is the back of intake manifold. You think the curse has hit ?
I hear it leaks from the front more often but how often from the rear?

Oh no, say it ain't so!