best time to find this is on a cold night with a torch, with mine there was no actual leak but a bit of steam coming out of a crack in the expansion tank which can only be seen when you have the correct light and temp. £79 later for the tank and some BMW coolant and all was good. I also did a full coolant flush while at it. Interesting the dealers use tap water which surprised me. I really think the cooling system is a weak point on BMW's, on my E36 4cyl all the components have been replaced, not only did it need new hoses but the various plastic parts the hoses attached too also turn brittle with age, because the system is under pressure when one goes you get a nice 'boom' and a ton of steam, I expect the Z4 to do the same in the next 7 years.
Coolant Light
- Thread starter Ste
- Start date