Loosing coolant around expansion tank area

[hbanko]

Hi Guys,

I am losing coolant and have to top up about every week. There is a puddle below the area around the expansion tank.

What is weird, that this only happens when I go for a short < 10 minute ride and stop the car. If the car is really hot, I would not see any water dribbling down there.

When I looked in the engine compartment I was not able to see any leak. But also had not the opportunity to open the bonnet when it happens. Jut hope its not the expansion tank himself.

The car is 4.4 2005.

Any clues?

[2002]

If you are sure that it is coming from the coolant reservoir, you need to get a new one. The hairline cracks are hard to see. This exact thing happened to my 2004 545i. Don't wait for it to explode as that happened to my brothers 2005 x5. Good luck.

[g300d]

Yup, probably a hairline tank crack or leaking seam.

Consider yourself lucky to be getting a heads up and get that sorted asap. Many others have more sudden and incapacitating failures in very inconvenient places with these cooling systems.

[hbanko]

I am not saying that it comes out of the expansion tank. The expansion tank is not far from the area the puddles forms under the car. Also it is weird that it just happens when the car is driven and then stopped 'still cold'.

To verify that it is not the expansion tank, I took a short 5 minute ride this morning and returned back to my home. Good that is Sunday today :-).

The water started to drip down the ground again and I checked the expansion tank. It was completely dry. From under the car I just saw the water was running down on the side of the oil cooler (?) which is below the radiator. The water was cold and also the radiator itself was cold.

Wasn't able to figure out from where it comes.

Later I took the car for a longer ride (20 minutes) and once back home no water was dripping down. So it probably has to do with thermostat or some tubes from thermostat to the radiator?

I doubt its the radiator as I do not notice any coolant loss once the car is hot for a while.

[X53Jay4.8is]

Originally Posted by hbanko

I am not saying that it comes out of the expansion tank. The expansion tank is not far from the area the puddles forms under the car. Also it is weird that it just happens when the car is driven and then stopped 'still cold'.

To verify that it is not the expansion tank, I took a short 5 minute ride this morning and returned back to my home. Good that is Sunday today :-).

The water started to drip down the ground again and I checked the expansion tank. It was completely dry. From under the car I just saw the water was running down on the side of the oil cooler (?) which is below the radiator. The water was cold and also the radiator itself was cold.

Wasn't able to figure out from where it comes.

Later I took the car for a longer ride (20 minutes) and once back home no water was dripping down. So it probably has to do with thermostat or some tubes from thermostat to the radiator?

I doubt its the radiator as I do not notice any coolant loss once the car is hot for a while.

The method your employing to find the leak is a waste of time. Just get a pressure checking tool for the vehicle and it will highlight your leak in matter of minutes. The fact that the coolant is still cold means that you have a hose leaking or hole in the system. This is not a hard leak to determine where it is coming from.