Water loss

[Sgr74]

I’m having to top up my water quite a bit recently and can’t see anything obvious. Besides looking under a bonnet in this weather isn’t much fun. To narrow the search a bit, where are the most likely places for a leak to develope?

 

[ph001]

Hairline crack in expansion tank. Probably won’t see it until car is fully up to temp and the system is pressurised. Hold it at 2000rpm on your drive until the radiator fan kicks in, then you will see it.

Assuming you are talking about coolant that is and not windscreen wash!

 

[tomrdy]

Could also be the temp sensor's O ring (look down the gap between the engine and the bulk head).

That's where my leak was and relatively common from what I gathered. Very cheap fix!

 

[RROB]

Had been having identical issues and then it split and spewed luckily while sat running on my drive....
I got a replacement expansion tank for £38 and will fit it this weekend.... (BMW part was £90) and I believe Meyle is the manufacturer (surprisingly mine is German made Meyle) !

 

[patriot66]

I've had a coolant leak on three occassions
1) The temp sensor o-ring failed.
Then 2) The expansion tank split
and very recently 3) The water pump bearings/seals failed
I replaced all three components myself. All easy, straightforward and relatively inexpensive jobs if you've got some decent tools and mechanical knowledge

 

[RROB]

Yup all confirmed today expansion tank had split..... fairly easy to swap over but a right pain in the arse to bleed system !

made easier by having car lifted at front (I just parked it in on my sloped drive) .... and just being patient !

 

[bz4kev]

Also check radiator for signs of coolant leaking had to change mine about 5 weeks ago had split top right corner

 

[Sgr74]

Thanks for the reply’s. If it’s dry tomorrow, I’ll take a look.

 

[Sgr74]

It is the expansion tank. New one ordered. Thanks for the help.