Coolant Leak - Please Look at Picture and Help
 

I noticed a coolant leak after a day of driving.

The leak seems to have been coming from the auxiliary water pump or one of the connecting hoses.

There was a whistle that was happening just a few days before I noticed the leak, but not sure if that's related to the leak at all.

So I identified the general area of the Leak. Not sure if its caused by the aux. pump failing and leaking, or if a hair line crack in either of the attaching hoses.

Any help would be really appreciated.. Thank you in advance!

I've noticed that the only post I found of leaking Aux. pumps were on 5 series sedan's and couldn't find anything on X5's. I guess the leaking aux pump does happen, but not sure how often it happens in X5's. Are these the same parts? Am I barking up the wrong tree by changing out my aux. pump??

Thanks!!

Ok, I am going to assume that is a 2000-2003 4.4i because a 3.0 would have that Aux water pump tilted to the left and that hose is standing straight up. Anyways, it is rare for that part to fail. I would first clean the area well, start the car and let it gut up to operating temp. Then check for the failure. Most likely point to fail are the connections leading to the aux pump. They are plastic and are only held on with spring clips. Check your expansion tank to see that is not leaking and spilling over onto those hoses. Check the surrounding hoses to see nothing is cracked as you said and spraying water to that area as well.

It's likely a plastic locking fitting, but you have no way of knowing since you haven't cleaned the area off to see where it is actually forming the leak. The only thing you can assume for certain is that you can start to look at where ever you see the highest point of coolant.

I cleaned the area as besta as I could without dismantling anything and couldn't see any particular area that was leaking. I will try to run the car again and see if I notice anything new. Thanks for your input!!

Sorry to piggy back, but I too have sprung a leak. I checked coolant level about a month ago and it was fine. This week I had multiple check coolant warnings. Opened expansion tank lid and it was quite low. I topped it up, my other half drove the car for the day. Upon return I noticed coolant leaking from just behind the passenger side (RH drive) lower front bumper. I have no visible leaks when looking into the engine bay on radiator tank and hoses? Any thoughts? oh and its a 4.4i 2004 with 133 ks, cheers

coolant leak
 

Actually my leak was dues to multiple issue which DID included the aux. water pump. As i suspected the Aux. Water Pump did go bad in my scenario, and after talking to a few repair shops, they confirmed that the aux. water pump goes bad more often then suspected. However your leak does look like its coming from that side of the car, so that would be my suspect if there were no obvious residue from looking under the hood. The aux. pump tends to leak from the lower seal, which I guess get's a hair line crack from something... maybe vibration, normal wear and tear not sure, or maybe its due to hot humid weather?? Hope it helps.

Hi, thanks for your reply. Looking closer at my leak it appears to be coming from expansion tank. Not from the hoses but the bottom and sides. Mainly from the bottom as this leaks onto the wheel arch and then onto my actual wheel as shown in pic. Anyway I'm dropping it off tommorrow at dealer. We shall see.
Cheers