technical E60 Noob

[freestyla]

Hi Guys and Gals
E60 525i 150,000 kms have it since new. Recently been using as daily commute (120 kms round trip) and found myself adding about half a litre of water weekly. Had a test done on the system to check for leakages, but none were found. Mechanic recommended selling the car as he believes the water would be getting lost in the engine (as there were no signs/marks anywhere). Silverton guy said there was nothing to worry about as the amount of water lost is minimal. Another friend recommended changing the radiator cap, which I did. I intend checking the water this weekend.
I would seriously appreciate any comments, advice or recommendations.

 

[TurboLlew]

Half a litre of water in a week/600km is not minimal. Is the car producing white smoke?

 

[freestyla]

No smoke at all.

 

[Gordvisr]

There might be a few reasons, one of wich oil might go to your engine, open oil cap and see if there is any choclate brown "sludge" on oil cap, the oil cooler and / or oil filter gaskets might be leaking through.

 

[Rotinaj]

Eh eh.

Hot compression test to see if the whave issues there, or you just have a leak from somewhere (quite normal for BM)

What area do you stay?

 

[freestyla]

Vereeniging

 

[freestyla]

There might be a few reasons, one of wich oil might go to your engine, open oil cap and see if there is any choclate brown "sludge" on oil cap, the oil cooler and / or oil filter gaskets might be leaking through.

Will do

 

[freestyla]

Flushed the coolant last weekend, replaced radiator cap and after daily commute for the week, everything looked okay. No need to top up water.
Also there was no sludge on oil cap or cooler.
Thanks guys