My daughter was driving her 2001 X5 4.4i home this weekend. Her college is about 35 miles away but she only made it about half way before she could pull over. We had her towed home and I am assessing the damage.
- both accessory belts are shredded to pieces
- The upper bolt that holds the AC accessory belt tensioner to the block sheared off leaving all of the threaded portion of that bolt (about 1") in the block. The belt tensioner and accessory belts were replaced in October 2020.
- The broken bolt rattled around and put some dents in the radiator (3 month old radiator)
- The cooling hose that goes from the bottom port on the ATF thermostat to the block adjacent to the alternator (11537500752) broke the nipple off the ATF thermostat and was severed near the other end. Consequently much of the coolant drained out of the system. And with the accessory belts shredded, the water pump wasn't being turned.
- several blades on the fan attached to the viscous coupling have been severed
I would be interested in suggestions what might have happened (what broke first).
When my daughter first noticed something was wrong she was on the freeway approaching a bridge (SF Bay Bridge). She wasn't able to pull over to a safe location until she got to the other side so she drove at least 5 miles with probably no cooling water. I have started the engine twice since and it seems to run OK. Of course there are warning lights/messages for alternator and coolant level but there is no Service Engine Soon light.
I removed the radiator for inspection and what coolant that was left in the radiator was clear and looked new. I did find a couple of dents in the radiator core, but I pressurized the radiator with air submerged in a tub of water and didn't see any bubbles from these areas. So I'm assuming the radiator while damaged is still integral.
I drained the oil and I didn't see any evidence of water in the oil.
I do see some creamy substance that looks like water and oil mixture at the outlet from the block right above the water cooled alternator. I don't really know what this fitting is connecting too? is it a cooling jacket for the alternator or what? This engine has an upper radiator hose that has a couple of branch hoses. This is one of the smaller diameter branch tubes.
At this point I am concerned that I may have a breach between the lubrication side and the cooling side because of the creamy substance found. Any thoughts about this?
My next steps are going to be to replace the AC belt tensioner and coolant hose and install the old accessory belts I saved and reinstall this radiator. At that point I can do a pressure test of the cooling system.
I am also wondering if there is a way to flush the cooling system? I remember the days when prestone sold a kit where you installed a tee fitting to your heater hose and could connect a garden hose flush out your cooling jackets into the gutter and down the storm drain. Of course this is frowned upon these days here in the SF Bay area. But is there a way to flush this cooling system?
Sorry for the long post. some pics are attached. Thanks for reading!