Mini Cooper Coolant Leak

[AidanGill]

Hi,

I'm just wondering if anyone can help me.

I have a Mini Cooper Park Lane 2006 and have had a leak problem a couple months now! i taken it to a garage and they said it was the water pump, so they fixed it... everything seemed good for a couple weeks, no leaks or anything... then the leaks start again! its defo coolant because my tank is empty when i look and with having white flags its easy to see the colour. i just want to know if anyone has had the same problem and knows what it is before i take it to the garage.

Thanks
Aidan

[Destructo]

I have an 02' MCS and had a similar problem. I was always running low on coolant, could smell it when I shut down the car. The problem was a faulty coolant overflow tank cap.

Also those overflow tanks are prone to cracking as well.

Hope this helps.

[AidanGill]

Thanks for that! i'll take it to the garage and get them to check the tank then. I hope it is that because i've had this problem for a while now, and having a new water pump fitted for no reason is annoying! but oh well haha. Thanks again!

[sad61t]

My understanding is that the MINI OEM plastic tanks have a mold-line that causes an inherent weakness in the design. The ONE & Cooper (Park Lane is an end-of line special edition Cooper?) have unpressurised systems with a fairly flimsy cap as it only needs to prevent the occasional loss from slop as you go over bumps, while the S has a pressurised system with a screw-on sealing cap.

After-market alloy tanks are available.

[AidanGill]

I'll give it ago buying a new Expansion Tank and see if that works! the leak only seems to happen after i have drove then been parked up for a while, so its a pretty fast leak. I just hope it is the Expansion Tank so i can finally stop thinking about the car leaking all the time!

[s m]

AidanGill said:

Hi,

I'm just wondering if anyone can help me.

I have a Mini Cooper Park Lane 2006 and have had a leak problem a couple months now! i taken it to a garage and they said it was the water pump, so they fixed it... everything seemed good for a couple weeks, no leaks or anything... then the leaks start again! its defo coolant because my tank is empty when i look and with having white flags its easy to see the colour. i just want to know if anyone has had the same problem and knows what it is before i take it to the garage.

Thanks
Aidan

As well as the tank cap/mould lines check the thermostat housing

[Destructo]

sad61t said:

My understanding is that the MINI OEM plastic tanks have a mold-line that causes an inherent weakness in the design. The ONE & Cooper (Park Lane is an end-of line special edition Cooper?) have unpressurised systems with a fairly flimsy cap as it only needs to prevent the occasional loss from slop as you go over bumps, while the S has a pressurised system with a screw-on sealing cap.

After-market alloy tanks are available.

You are spot on. They molded the tank right at the half-way point and it is prone to cracking due to the repeated heat exposure. It's a serious engineering overlook by Mini.

Do you have any more information on those alloy tanks? Thanks!

[sad61t]

Destructo said:

You are spot on. They molded the tank right at the half-way point and it is prone to cracking due to the repeated heat exposure. It's a serious engineering overlook by Mini.

Do you have any more information on those alloy tanks? Thanks!

For an MCS, look at Forge Motorsport's tank. Lovely shiny alloy baubles, perfect for decorating the Christmas tree:
http://www.forgemotorsport.co.uk/content.asp?inc=p...