No Power Steering and Battery Light
 

So this past week, my E53 2002 X5 3.0i has been acting up. It notified me on four separate occasions that my coolant level was low. I checked it, and it was completely empty. So I filled up coolant every time.

Yesterday, I was driving and as I was making a left turn. My power steering went out, and a red battery indicator turned on, on my instrument cluster.

I've been researching the problem, and I found that you lose power steering and the light turns on when the alternator isn't working.

I checked to see if the belt was still attached, and it was.

Now I am thinking that a leak or something else from the coolant may have damaged my alternator. Is that possible? How can I diagnose this? I haven't seen any coolant leak out at all in the past week. Maybe it leaks out when I am driving... IDK

I'm also currently in a town with very little european car mechanics... so I am hesitant to bring it to any of the mechanics here.

I'm not sure about the pre face-lift models but I know on the face lift models the alternator are water cooled, do you might be on to something suspecting that the alternator is the source of your coolant lose.

You can check your alternator by simply hooking up a multi meter to your battery while the car is on and measuring the voltage (I believe it should be around 14-14.4 volts while the engine is running).. If you don't have a multi meter, do a quick Google search on how to unlock your OBC and you can also read your battery voltage from the display in your cluster (again, not sure if you can do this in the previous face-lift models)

Our trucks act really funky when they don't get the power they need from the battery/alternator, so I hope your power steering issue is caused by just a faulty alternator.

Unlock the OBC and check the battery voltage while the engine is running, should be between 13.5 and 14.7. Any lower and the alternator is toast and higher and the alternator is toast.

Did you also check if the belt was loose? The belt can be in place and loose because it is about to fail or because of a tensioner. Coolant residue can also cause it to slip. A loose belt would not be turning the associated pulleys adequately which could result in your symptoms. Have you cleaned the belt since the coolant spills? Coolant leaks don't go away. Are you checking the coolant level frequently or waiting until the warning light comes on?

Your alternator is air cooled on the 3.0, however coolant entering the alternatr housing can lead to failure later on. That exact issue occurred on the CEO's 325i after a pin hole in the upper radiator hose sprayed coolant directly into the alternator.

The fact you have no power steering is a strong indicator of belt slippage which is probably resulting from coolant residue, or a failing belt tensioner. This could also be causing reduced alternator output. I'd check the belt and tensioner first, then address the alternator if there's no change.

2002 X5 3.0 260,259 miles
2004 325i 115,000 miles

I didn't check if the belt was loose, but I will do that once I get home from work. I haven't actually seen any coolant spills, I just keep noticing the coolant disappearing from the reservoir.

Thanks for your insight! I will be sure to do that!

So I had a chance to check my BMW Engine Housing. The belt around the alternator seemed to be on correctly, tightly and it was spinning just fine. However, the belt that seemed to spin the radiator fan (or the belt that is behind the fan system) has completely fallen off the track.

Are there two different belt systems? And would this explain all my problems?

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EDIT: Actually, I think the thing that I was previously thinking was the alternator, is actually the AC Compressor. So it does seem that the alternator belt is off the track.

There are two belts. The belt closest to the radiator drives the A/C compressor. The other belt drives the fan, alternator, water pump and steering pump. Without the water pump turning, the coolant is not circulating. No circulation of coolant means the engine will overheat the coolant until it becomes steam. The cooling system is not capable of handling the pressure steam will create. The coolant will exit the system at the weakest point. The Inner belt, closest to the engine needs to be replaced. There is a reason the belt came off. It could be that it is worn out. It could also be that a pulley or tensioner or one of the accessories driven by the pulley is bad. You will need to find out why the belt came off. You will need to be sure the belt is routed properly. I would certainly not run the engine until the belt is replaced.

Okay good to know... So I need to replace the belt, I can't just put it back on the track?

It depends on why the belt came off. Inspect it carefully for cracks and for places it is not smooth at narrowest part of the V. If it passes you can try putting it back on. Make sure you inspect all pulleys and tensioners that are driven by the belt to see if they turn freely and don't wobble. Since a belt is not expensive and from my experience it often soon after fails, you should replace it. You will need to be on the alert for other problems since it sounds like the coolant was completed boiled out twice. I am surprised you didn't smell coolant, see steam or have an overheating light on the dash.