[Cerealkiller]

I’ve been getting a low coolant warning when starting for the first time each morning but it goes away in the afternoon. I checked the coolant levels and it looks fine. Anyone else having the same issue?

[RockCrusher]

Originally Posted by Cerealkiller

I’ve been getting a low coolant warning when starting for the first time each morning but it goes away in the afternoon. I checked the coolant levels and it looks fine. Anyone else having the same issue?

Check the coolant level with the engine cold -- and the car level -- before you drive the car very much.

Be careful. After some time the plastic tank will develop a stain that can make it look like the level is ok but a closer inspection will find the actual level is low.

If the level is low I've used distilled water to top up the level.

Don't overfill but cold I like the coolant level at least halfway between the low and full lines.

Be sure the cap is on securely. Some caps can require considerable effort to screw on properly but don't over tighten.

If the cap is not on securely it can vent water vapor when the engine coolant is hot and the system can lose considerable fluid (water). With one car that proved to have a defective cap which vented vapor at a too low a pressure in about one month of daily use the coolant level dropped by nearly 1 gallon.

Once you have the coolant level good and have noted the level -- take a pic -- check the level before each day's use to see if the level is dropping. If it is there's a leak and you need to have the car in and get the leak diagnosed.

If the low coolant light comes on and the level is good this can arise -- at least with older cars, that is cars with some time/miles on them -- the sensor in the tank getting fouled.

As per my auto tech buddies' recommendation I have the engine coolant drained and refilled about every 4 years. Among other benefits it can prolong the life of the level sensor.

[PP3121]

Ditto to OP. After several rounds of on and off messages, checked level on level ground when cold. Sure enough, very low!

Followed BMW recommendations for adding more coolant. Since filling, no more messages.

As mentioned, if level is good when measured cold, may be the sensor is faulty.