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Respected professionals,
About 100 millilitres of coolant per thousand km is leaking out of my vehicle. The vehicle in question is a N57D30-powered BMW F11 530d.
I brought the cooling system's pressure up to 2 bars, but I still couldn't find where the leak was coming from. But if I turn the engine over while it's running and look attentively at the front of the engine, I can see coolant dripping down the intake manifold.
My apologies, but I don't see any coolant pipes in that region (refer to the attached image).
Hopefully it's not a leak from a cracked cylinder head, but it's worth considering. Alternately, is there another potential leaky supply of coolant in the vicinity? Approximately 100,000 km ago, due to a timing chain breakdown, the cylinder head underwent refurbishment.
It does not appear that the oil filter housing or the exhaust gas recirculation (EGR) system are the culprits, since I have already examined both.
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Strange leak of coolant N57D30 BWM F11 530D
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tonysoprano
- Posts: 46
- Joined: Mon Feb 02, 2026 8:43 pm
I don't see coolant, but I do see what appears to be an oil mist leak surrounding the swirl motor; such a leak is normal as manifolds age.
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Edmonston33
- Posts: 67
- Joined: Mon Feb 02, 2026 8:45 pm
I am grateful. That sounds fantastic. The oil was also visible to me. The vehicle does not experience significant oil loss, though. I don't detect any leakage at 2 bar of pressure if it's only oil, which seems sense.
1) Would it make sense that the pouring becomes more noticeable as the engine revs up (greater oil pressure)?
Secondly, isn't this a recognised source of frequent failure in the cylinder head?
My third question is whether or not I can use radiator coolant dye to find the leak's origin. If you want to know if it's a combination of oil and coolant, you can do that next. Alternately, you might just wait to see whether the problem is worsening before acting.
The assistance you provided is greatly appreciated.
1) Would it make sense that the pouring becomes more noticeable as the engine revs up (greater oil pressure)?
Secondly, isn't this a recognised source of frequent failure in the cylinder head?
My third question is whether or not I can use radiator coolant dye to find the leak's origin. If you want to know if it's a combination of oil and coolant, you can do that next. Alternately, you might just wait to see whether the problem is worsening before acting.
The assistance you provided is greatly appreciated.
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Imlach_C220
- Posts: 31
- Joined: Mon Feb 02, 2026 8:46 pm
pump for water? That's what happened on my e46 330d: I couldn't locate the leak, so I checked the water pump. A wobbling, viscous fan indicated that it was working, so it would be worth a go, but I'm not sure your car's setup is different.
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Edmonston33
- Posts: 67
- Joined: Mon Feb 02, 2026 8:45 pm
Thank you for responding. We changed the pump two years ago. Due of this, I do not believe the perpetrator.
Recently, I was researching images of the engine's upgrade. Using blue fluid, I outlined a coolant channel on the image. This is precisely where the dynamo's engine mount meets. Therefore, close to where the present leak is located. I'm starting to worry that it may be the engine head or the gasket....
Recently, I was researching images of the engine's upgrade. Using blue fluid, I outlined a coolant channel on the image. This is precisely where the dynamo's engine mount meets. Therefore, close to where the present leak is located. I'm starting to worry that it may be the engine head or the gasket....