[AndyG414]

Hello,

My E90 has 120xxx miles on it. I can tell my oil filter housing gasket is at the point where it could be changed. I recently noticed that my coolant level starting getting low over the past couple of days. I know for certain the coolant is not mixing with oil. It appears that the coolant may be leaking from the oil filter housing gasket (coolant hose runs through the oil filer housing.) I can see the puddle below it and the fan blew some of the coolant on to the top of the engine.

I know the oil filter housing gasket is a common failure. However, I would have expected an oil leak, not a slow coolant leak. Has anyone else had this issue or anything similar to it?

[blackturbo]

It could also be that your coolant reservoir cap is leaking fumes. At that mileage I would add a new cap, they are known to fail. No need to spend money on getting the cap compression tested. Put it into the new cap.

Check the Radiator. I had the worst luck with the water pump AND Radiator leaking on me before...

[kkasson]

It's possible that the upper radiator hose is leaking instead of the gasket.

Another place to check would be the small vent hose above the radiator. It runs from the expansion tank across the top of the radiator to the upper hose.

[Meeni]

I had the same symptoms it was the hose connector on the driver side of the radiator: the plastic was completely heat roten, I had to change the hose connecting the expansion tank to the radiator, and the main hose from the OFH to the radiator (the plug was roten too).