Ghost coolant leak?

[Steiner]

Hey,

I noticed a huge puddle of coolant under my Z4 a few days ago. I looked around, and saw no obvious point of leakage and filled the car up.

The following days I actively monitor the coolant level; it remains the same - full and good to go. Then a few days afterwards, I notice that the car has pissed itself once more. I managed to have my mechanic take a quick look at it. He noticed that the area closest to the coolant cap was somewhat wet, but couldn't see any damage. This was ~two months ago, and it hasn't spilled a drop since then.

Anyone have a clue why this might be?

 

[Swiftly]

Just a thought, it's not water created from the air con, mine does this sometimes, especially if it has been hot and I have used the air con for long periods

Otherwise can't advise sorry

 

[Steiner]

Just a thought, it's not water created from the air con, mine does this sometimes, especially if it has been hot and I have used the air con for long periods

Otherwise can't advise sorry

I had to refill the coolant, and there were water spots on the refill cap so I don't think that's it sadly.

 

[Swiftly]

It was worth a shot, hopefully someone else might be able to help

 

[srhutch]

The expansion bottles seems to suffer from cracking. There have been a few on here recently.

 

[sammysquid]

my expansion tank didn't crack but the orings went, gave me random leaking and then not leaking might be worth a thought?

 

[Steiner]

Yeah, I'll have the expansion tank looked at!

I'm a sucker when it comes to realoem browsing. Could anybody give me a hand finding the expansion tank there?

Thanks!

 

[Swiftly]

I believe your zed is a 2003, 2.5i, if so its part number 3
http://www.realoem.com/bmw/showparts.do?model=BT31&mospid=47796&btnr=17_0143&hg=17&fg=05

 

[Steiner]

I believe your zed is a 2003, 2.5i, if so its part number 3
http://www.realoem.com/bmw/showparts.do?model=BT31&mospid=47796&btnr=17_0143&hg=17&fg=05

Thanks, I appreciate it!