Joesph530

I just bought my 2006 530xi about 3000 miles ago and I don't drive the car much. It may sit all week without leaving the garage.

Recently after being driven ~90 miles and sitting on a sloped driveway all night, the Low Coolant warning appeared on the i-drive screen as I backed out of the driveway. I had had this happen on a previous E39 model and did not think much of it. I watched the screens, did a system check and everything else was okay. After the warning did not go off, I manually checked the coolant level and added less than 10 ounces of water, restarted the car, and the low coolant message was gone.

A month of no warning messages passed and I recently drive the car on 700 mile round-trip with no warnings, so I assumed the low coolant issue was a glitch. The car sat in the garage for a week without being driven and I went to back it out and the warning came on again. I immediately checked the coolant level and it required about the same amount as before.

I drove the car on a ~50 mile trip, let it set overnight, and manually checked the coolant level. It was fine.

There is no indication of any leaks on the floor and the car sits in the garage for days at a time, so it should be visable if that were the problem. There are no other signs to indicate a blown head gasket.

This is my first E60, as my other 5 Series cars have been E39s. Does anyone have any suggestions or things I should look for before I make a service appointment for an issue that they will not be able to recreate? I don't want to take it in if there is no need, but I also don't want to risk harming the engine.

Any feedback or additional signs to watch for would be greatly apprecaited. THANKS

kscarrol

Yes, had this in both my '04 and '08 cars. Simply top off the coolant in the expansion bottle under the hood. My dealer has done it for me as a courtesy because I am under warranty though some dealers won't do it.

Joesph530

So, I should not be overly allarmed that it has happened twice within 1000 miles? Even before this occured, I was considering having the coolant flushed the next time I take my car in for service. Hopefully, that service will confirm that nothing is seriously wrong.

I might be a little paranoid since I just bought the car.

NoName545i

use distilled water

pukka

I wouldn't be alarmed, but twice within 1k miles is a bit suspect. The last time around did you add plain water again or antifreeze?

Joesph530

The first time, I was on the road and used bottled water as it was Sunday morning and all I had. The most recent time, I used plain water again because it was the weekend and I was not sure what is the proper coolant to use. I plan on having the car is due to have the brakes flushed as soon as I can get it in and I was going to have the service center top off the fluids with the recommended liquids.

Hopefully, there will not be a next time, but I will use coolant if this occurs again before I get the car serviced.

pukka

Just adding water won't do any short term damage to the engine, but it will evaporate thus giving you the frequent top offs. Its always good for a 50/50 mix, especially in hot climates.

I use Prestone 50/50 - you can get the pure stuff and mix it yourself for a little bit less $$$

JMM525i

I use Prestone Extended Life without diluting it because normaly if you have to top off you coolant receptacle it should need just a bit, if it needs more than a little then there is leak somewhere. Now if you have had top off water twice in the receptacle "Just adding water won't do any short term damage to the engine, but it will evaporate thus giving you the frequent top offs" then you may need to add the right liquid. One advise that I can think of is the coolant unit when you open it has a floating stick that tells you when it is full or if it needs more. You may want to check out if it is at the correct level. GL

Spaceroach

You can buy a jug of the coolant BMW uses at the dealership for around 25 bucks.

And having to top it off is common.

krusir

There could be minor leaking in the system. I do have exact same symptom in my previous e39 540i. The valley gasket in the middle of V-block is leaking. I did not know it until the leak goes worse and start drip from transmission case. Same idea could apply to e60 with I6. Not sure where is the weak point of this engine though.

The funny thing is that you only get this warning when engine is cold during morning, if you shot the engine down. Wait for 5 seconds then restart, the warning is gone. If you check the coolant later, it is in spec. I carry a bottle of coolant with me in trunk, stop engine immediately at morning when I got the warning. You will see the coolant is low at that moment, top of it. Used to do this few months once until within a month.... then I know I have to fix it.

After I replace the valley gasket, the problem is gone until I sold the car.

Simon.