Coolant Leak Above Water Pump

elevation_35 · 01-12-2025, 04:25 PM

Hello everyone,

I have a persistent coolant leak from the area above the water pump. I’m not too sure where it can be coming from but I have attached an attachment that points to the area behind the bolt it leaks from, and a YouTube video for reference.

For context I replaced my water pump and thermostat approximately 4 months ago and this leak only developed a few days ago. Before this I was not losing coolant at all and now the coolant will go from max to min within an hour. I’m really hoping this isn’t a case of a cracked water pump.

Any help on this would be greatly appreciated!

Youtube Video

elevation_35 · 01-13-2025, 07:49 AM

Okay I am thinking this is a case of a cracked expansion tank. I can replicate the leak and can see coolant leaving the expansion tank if I relieve some pressure via the cap once the car is warmed up. However, I am not 100% certain as the coolant doesn’t leave if I don’t loosen the cap.

01-12-2025, 04:25 PM	#1
elevation_35 New Member 3 Rep 16 Posts Drives: BMW 335i N54, BMW 330i N52 Join Date: Jul 2024 Location: UK iTrader: (0)	Coolant Leak Above Water Pump Hello everyone, I have a persistent coolant leak from the area above the water pump. I’m not too sure where it can be coming from but I have attached an attachment that points to the area behind the bolt it leaks from, and a YouTube video for reference. For context I replaced my water pump and thermostat approximately 4 months ago and this leak only developed a few days ago. Before this I was not losing coolant at all and now the coolant will go from max to min within an hour. I’m really hoping this isn’t a case of a cracked water pump. Any help on this would be greatly appreciated! Youtube Video Attached Images
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01-13-2025, 07:49 AM	#2
elevation_35 New Member 3 Rep 16 Posts Drives: BMW 335i N54, BMW 330i N52 Join Date: Jul 2024 Location: UK iTrader: (0)	Okay I am thinking this is a case of a cracked expansion tank. I can replicate the leak and can see coolant leaving the expansion tank if I relieve some pressure via the cap once the car is warmed up. However, I am not 100% certain as the coolant doesn’t leave if I don’t loosen the cap.
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