Losing Coolant

[Unregistered]

I need some help w/ my e34 525i 1990 car. The "COOLANT LEVEL LOW" warning came on my car yesterday. Looked in coolant tank and it was very low almost empty before i headed to work. I filled it up before I went to work 20 miles back and forth. The coolant level warning came on again this morning and coolant was all gone again. I"m not sure if it leaked out at work but I pust some more this morning and didnt see it leak out? what could be causing this? What can I do to diagnose and fix. Thanks.

[Aaron Bakos]

The upper neck on the radiator is a weak spot, over time the thing just gets soft and falls apart. If you hurry you can still swipe my old radiator out of the dumpster so you can see what I mean :(

You can also check if the O-ring around the coolant level sensor is bad...

My advice is to put a bunch more water in, run it around town and then park it. You should see the leak pretty quick after she's warmed up. You said you put coolant in yesterday morning but couldn't see it leak out, so it's likely that the system needs to be pressurized (as much as it can be when you've got a leak).

Hope some of that helps...good luck!




I need some help w/ my e34 525i 1990 car. The "COOLANT LEVEL LOW" warning came on my car yesterday. Looked in coolant tank and it was very low almost empty before i headed to work. I filled it up before I went to work 20 miles back and forth. The coolant level warning came on again this morning and coolant was all gone again. I"m not sure if it leaked out at work but I pust some more this morning and didnt see it leak out? what could be causing this? What can I do to diagnose and fix. Thanks.

[Unregistered]

Drove for about 15min didnt see any change or leak on the floor when I came back and parked it for a few hours?

[Trevor]

One thing to check is your water pump.
I had a recurring leak that became progfessively worse. When I had the roadworthy certificate check for registration I asked the mechanic to check out my cooling sytem for leaks. He said that my water pump had a leak and quoted $700 to fix (Aussie $$$). I bought a new watre pump from BMW along with 2 bottles of BMW cooant (don't use anything else) and replaced myself in about 2 hours. Toatl cost came in under $200 (Aussie $$$). Water leak gone.

That is one possible cause.
You'll need to check around your water pump with the engine warm. Use a torch and a mirror to help.

Good luck.

[Aaron Bakos]

Don't forget the possibility of the heater core. It's possible to have a coolant leak inside the car...but you should be able to smell it if that's the case.

Check the radiator for obvious signs of leaking...I don't know what else to tell you -??