Coolant Thief!

[decio]

Morning all,

i wrote sometime ago that i had a coolant leak, which was obvious because of the big puddles on the drive and i could quite clearly see the drips dropping. i took the underpan off the car so i could see more clearly what was being left on the drive. now however the drips seem to of stopped and i dont see anything on the driveway anymore, yet every morning when i check the coolant level the tank is empty, has anyone got any ideas?? the only options i can think is dodgy thermostat/temp sensor which is pushing too much water through the system, iv got a pin hole leak somewhere, or every night somebody is lifting up my bonnet and syphoning out the coolant out of my car! appreciate this isnt a z4 specific problem, but if anybody with a bit more knowledge than me can suggest what may be happening or a way to identify it i am all ears!

Cheers

Andy

Hi mad_mackem I have the same problem with my Zed. It is two years old and I figured out to change the coolant at an authorized bmw service. I know that the coolant change should be performed every 5 years app, but I said to myself why don't do that - can't make any harm. So few days ago I came in bmw service and they changed Oil,oil filter,fuel filter,air filter,micro filter and coolant. After few days I went for a trip, and after 20 min coolant low level light has turn on. Immediately went in service and told them about the light...they wait for engine to cool down check the level and added approx half pint of water. Everything was good till few days ago when I brought my zed out of garage to wash it. I've checked the coolant level and it was below minimum. I forgot to say that 6 days passed form last drive. I topped up the expansion tank with distilled water and brought the Zed again in service station. He is still there. I'm picking it up this afternoon. The mechanic is stating that there was no leakage these few days, they pressurized the whole cooling system on 1,5 bar and left it under pressure for a whole day and the pressure didn't drop. The had gasket is not a problem because there is no CO2 in the cooling system. The main indicator of a broken gasket is that even after the engine cools down there will be a huge amount of pressure still remaining in the cooling system (a part of compression is going in the system) it is manifested like a volcano from the tank. Now everything I have to do is to check each day the coolant level...maybe my Zed is also a subject of coolant pilferage !

 

[mad_mackem]

all i can recommend to do is the advice i was given, take the underpan off, start the car let the engine warm up and wait for the thermostat to release the coolant and then see if you can see any water dripping onto the drive from the front of the car? if the car just sits there for a few days it might not leak, best bet is to leave it running for a bit on the drive.

 

[alekos911]

Dear decio what happened to your car? Did you figure out what was the problem? Was it a head gasket problem or sth else?