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View Full Version : Intermittent Phantom Coolant Light (yellow)


jorbon
11-27-2012, 10:06 PM
Comes and goes as old Silvie pleases... Coolant is full/fresh.

Any ideas?

Wondering if PO's angel eye install tied into something that is shorting? But that's a guess without any digging at all.

Thanks in advance.
Lespaulman16
12-16-2012, 10:38 PM
Could be a failing coolant level sensor. They tend to act like this as they are going bad, as they normally fail due to internal shorting.
jorbon
12-27-2012, 11:15 PM
Good to know- thanks.
danewilson77
12-28-2012, 06:18 AM
......But.....I would be watchful of coolant level as well.
az3579
12-28-2012, 02:23 PM
Whenever you replace the coolant expansion tank (every 60k miles), be sure to do the sensor as well. The sensor is a common failure item.


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BavarianZHP
01-01-2013, 01:16 PM
How low does the coolant have to get before it triggers the coolant light? I had to add 400 ml last time and mine failed to notify me, so I'm thinking mine may have failed.
6appeal
01-04-2013, 09:44 AM
I had the same issue. I replaced the thermostat and everything was fixed. Your thermostat is probably stuck closed. One mechanics diagnosis trick you can do to confirm this is to turn on the car and leave it running for 10 mins. Turn it off then touch the two rad hoses. If the hose on the left (passenger side of radiator) is cool to the touch (compared to the warm driverside rad hose), your thermostat is stuck closed. Solution is to replace your thermostat and make sure the system is bled properly. When topping off the coolant be sure to use a 50/50 mix of OEM BMW Coolant and distilled/de-ionized water.

But before you do this, take the washer fluid level sensor and plug it into the bottom of the expansion tank. These two sensors are the same and are interchangeable. By doing this you eliminate the possibility of a broken coolant sensor. Also to note is that the coolant sensor was changed/updated at some point in E46 production. Depending on when your car was made you may have the old coolant sensor. The new one is light-blue in colour and all plastic and the old one is made more of clear plastic with a visible reed.

Hope this helps.