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Excessive Coolant Loss

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Labusthetormentor
Posts: 35
Joined: Mon Feb 02, 2026 9:03 pm

Have had the low coolant light come on twice in 45 miles. Had to drive the last few miles home from work tonight and noticed that the expansion tank was empty, requiring around 1 litre of coolant. Upon inspecting the engine bay, I noticed coolant leaking near the oil filter. The underside of the thicker hose was wet, as was everything below it. Is there anywhere else in this area where it could be leaking, or do you think it's the hose? I just had a torch on my phone to look around, but I captured a quick picture of the spot where I think the leak is, and there's a plastic fitting on the end of the line that goes into the engine's top.

N47, 330d 2011
Labusthetormentor
Posts: 35
Joined: Mon Feb 02, 2026 9:03 pm

Probably coming from the hose's underside, just to the left of the oil filter? If coolant isn't dripping from someplace, then what?
Labusthetormentor
Posts: 35
Joined: Mon Feb 02, 2026 9:03 pm

:D :( :(
MMCGARAGE
Posts: 37
Joined: Mon Feb 02, 2026 8:58 pm

In order to remove the top bolt, loosen the manifold and lift it slightly; this is necessary when the coolant flange splits near the oil filter.
Labusthetormentor
Posts: 35
Joined: Mon Feb 02, 2026 9:03 pm

Thank you, @MMCGARAGE. Is this a simple task? Just loosening the intake without removing any wire harnesses, etc., is all that's needed, according to a quick look on Google, to remove the intake. I was planning to hire a garage, but now it seems like the wrong time—a skip is being dumped down on my drive on Friday, so I won't be able to use my garage. However, if it's not too complicated, I could do it on the street outside my house.
MMCGARAGE
Posts: 37
Joined: Mon Feb 02, 2026 8:58 pm

Indeed, it is quite simple to accomplish. If the manifold is loose, you can tilt it up to provide enough space, but removing it is the official method.
andy_bmw_1965
Posts: 60
Joined: Mon Feb 02, 2026 8:37 pm

Verify the storage tank. My one tore all the way down the back!
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