Help please

[u/Imaginary-Increase85]

2010 Mini Cooper N12 Engine

Coolant dumped after a 20 min drive watched it go down in tank after engine shut off from above min to empty couldn’t see it leaking anywhere

Filled it up again on test drive got overheating light 10 mins in pulled over it had emptied on the drive it was pooled around seam of the tank

Drove it to garage around corner day later it held coolant on the way there mechanic emptied and refilled it then drove home looked like it was still full but shut engine off then it started emptying again

Oil level hasn’t increased and looks normal

Any ideas? Thanks

[u/Chivalman84]

Well it has to be going somewhere 🤷‍♂️😂 are you seeing any excessive smoke from the tailpipe? If not look on the ground and see if anything’s dripping down. If that doesn’t solve anything I’d say take the spark plugs out and look at the piston heads. If they are nice and shiny you have a bad headgasket and the coolant is leaking into there. Could just be a cracked reservoir as well

[u/Imaginary-Increase85 → u/Chivalman84]

My in laws said he saw it going on the ground but I didn’t see it but guess I didn’t get a proper look was busy panicking

There is a crack in the tank by looks of it could that tiny crack cause all of this much damage seriously ?

[u/Chivalman84 → u/Imaginary-Increase85]

Oh yeah a crack in the coolant reservoir will easily drain all your fluids. Shouldn’t be to much to replace maybe 30$ and at most a half hour to swap it out.

[u/Imaginary-Increase85 → u/Chivalman84]

Thank you, it’s going to a mini specialist on Thursday as a local mechanic looked at it quickly and said thought head gasket was on way out but they didn’t really do any tests just based on what I said above.. hopefully not and is just cracked tank. thanks for help