6 replies to this topic

[Poppa]

Hi all I hope someone can offer advice...
After only 9 miles today My 1993 spi cooper decided to overheat on me on the motorway.
The recovery guy turned up & discovered i have a cracked expansion tank & all so the rad cap had decided to leak too.( where the underneath part joins the actual cap) My questions are What would have caused this & where can I get a new expansion tank as all the suppliers i have called tell me they are no longer made!!!!!!!. Or would i be able to use a diferent tank? Many thanks

[Pauly]

SPI's never had an expansion tank, they are fitted with side mounted radiator with built in filler (like other minis), only later MPI models had expansion tanks.

Unless its been fitted with a front mounted rad.

Paul.

Edited by Pauly, 02 May 2009 - 12:19 PM.

[Poppa]

SPI's never had an expansion tank, they are fitted with side mounted radiator with built in filler (like other minis), only later MPI models had expansion tanks.

Unless its been fitted with a front mounted rad.

Paul.

I have a side mounted rad &well mine has one mounted under the passenger side wing & if they werent made, how come parts places have them on their lists but are no longer available?

Edited by Poppa, 02 May 2009 - 12:24 PM.

[Aria Aradhea]

Some SPi and later 1275 Minis did come fitted with expansion tank, also some export models.

The overheating may be caused by the rad cap leaking, causing pressure loss in the system. This could also be the factor contributing to the cracking of the expansion tank, the coolant's so hot it cracked the plastic tank. The rad cap for cars with expansion tanks needed the correct cap like this: Mini Spares link..

First, the obvious thing is to replace the rad cap. If you can source another expansion tank, then use the specified cap. But if you decide to ditch the expansion tank, then the regular 15lbs cap will be fine. As I understand it, the expansion cap works by storing the excess water that were being spewed from the system when hot and then, thanks to the pressurised system, retract it back to the radiator. In theory, no water loss should happen. You can remove the expansion tank without worries, because unlike the ones on the MPi, it's not an integral part of the cooling system, just an add-on.

Second, check your cooling system thoroughly. Flush your rad, check the waterpump, thermostat etc. to make sure that everything is in order.

Somebody will surely come along with a better advise and knowledge than me, but I believe that's the least thing to do...

Edited by Aria Aradhea, 02 May 2009 - 01:11 PM.

[Poppa]

Some SPi and later 1275 Minis did come fitted with expansion tank, also some export models.

The overheating may be caused by the rad cap leaking, causing pressure loss in the system. This could also be the factor contributing to the cracking of the expansion tank, the coolant's so hot it cracked the plastic tank. The rad cap for cars with expansion tanks needed the correct cap like this: Mini Spares link...

First, the obvious thing is to replace the rad cap. If you can source another expansion tank, then use the specified cap. But if you decide to ditch the expansion tank, then the regular 15lbs cap will be fine. As I understand it, the expansion cap works by storing the excess water that were being spewed from the system when hot and then, thanks to the pressurised system, retract it back to the radiator. In theory, no water loss should happen. You can remove the expansion tank without worries, because unlike the ones on the MPi, it's not an integral part of the cooling system, just an add-on.

Second, check your cooling system thoroughly. Flush your rad, check the waterpump, thermostat etc. to make sure that everything is in order.

Somebody will surely come along with a better advise and knowledge than me, but I believe that's the least thing to do...

Thankyou for that reply, You have cleared up for me, that i would be able to run the car without the tank, till I can get another.
But would i have to block the overflow pipe to create a seal or would i just leave as is?

[Pauly]

SPI's never had an expansion tank, they are fitted with side mounted radiator with built in filler (like other minis), only later MPI models had expansion tanks.

Unless its been fitted with a front mounted rad.

Paul.

I have a side mounted rad &well mine has one mounted under the passenger side wing & if they werent made, how come parts places have them on their lists but are no longer available?

Thats a overflow canister (bolted to the inner wing right underneath the wing??), any excess water or if it overheats then it will flow into this tank, it doesn't effect engine running, and most people bin them, when they are putting on a new wing etc. Wouldn't worry about it. If the rad cap is leaking then replace it.

If it overheats whilst driving then it can be either a broken thermostat or possible headgasket failure.

[Poppa]

Thankyou! I just had it running on the drive & within about 5 mins she overheated. So will be flushing the system & changing the thermostat. Hopefully its nothing more serious!