Top up water every two days!!

[james318i]

Hi guys!! I bought a 318i 2.0(66k mileage) somewhere in April'08. After two months of city driving I’ve decided to go to the Genting Highlands. All of a sudden, during climbing the expansion tank gave away & towed to my workshop. I changed the expansion tank & thermostat. Now I have to top up the water every two days once (about 1/2 liter). My mechanic tried to look for the leakage area, but they failed. Could you help me to solve this matter? Thanks alot!! Cheers!!

 

[tamade7]

All the while I don't need to top up water and then one day the coolant low indicator lit. I top up water and ask my mechanic to do a pressure test. He told me nothing is wrong but I still need to top up. When I got my car for service, my mechanic found out that the area around the thermostat has a very minor leak.

Ask your mechanic to do a pressure test. If pressure looks normal then your leakage is very minor. If not it will shows on the pressure test.

 

[jims2005]

firstly, E46 consume more water because the engine gets heated faster. if you start you car for say 15 minutes, you might need 3 hours to cool down. so it is quite normal to refill with coolant or water frequently. However, this could also due to the expansion tank leaking, or the ~1.5 inch diameter hose that is leaking. try to search if there is any "red/brownish" stain below the radiator cap. the hose cost around 200-300 range. hope i answered your questions.

 

[turbology]

Do a pressure test at your cooling system.
Since you had overheated problem, some of the seals could have gone bad.

 

[kshapawi]

where can do the presure test? My car overheat yesterday but the meter didn't go up to the RED indicator. When to Mspeed just now and kenny suggested me to changed my radiator, water pump, break host.

 

[turbology]

My rule of replacing new parts : from the cheapest to the most expensive, including labor.

Try hose first, then maybe radiator, then water pump.

 

[affan66]

if the car has overheated, please change the thermostat. it could have already gotten stuck. The pressure test will ascertain whether you have leaks in the hoses, water pump cover and/or gaskets. One forummer suggested using NASA coolant instead of BMW coolant as it is greener in colour. If there is any leaks, you can see where the leak is coming from.

 

[Hellraiser]

try checking out the radiator cap. car over heating many have melted the rubber in the cap thus resulting with no pressure to push the water. water then escapes as vapor as you drive. then again, it could be one of those micro leaks which only happens when you drive and is very hard to detect when you're not driving.