Mini cooling systems - any knowledge out there?

Oscar · Post by **Oscar** » Mon Apr 16, 2007 2:59 pm

Hi

I've volunteered myself to investigate an overheating late-model mini. I think the rad is just blocked, but may be wrong. It all looks pretty simple, but is there anything I need to be aware of?

O

Stewart (oily!) · Post by **Stewart (oily!)** » Mon Apr 16, 2007 3:57 pm

Everything

they are just horrid, I suppose look for the obvious, blocked rads, the hoses used to be rather poor on them so give them all a squeeze as they can collapse internally, also check that the thermostat is opening.
Stewart

jeremy · Post by **jeremy** » Mon Apr 16, 2007 4:03 pm

By late model do you mean BMW mini or the British one with the A series engine (or A+ in this case.)

If its A or A+ the water pump will probably leak as they seemed to have a design life of about 2000 miles. If you have to replace it a non-genuine one is best.

I'd agree with Stewart - the usual culprits first!

Oscar · Post by **Oscar** » Mon Apr 16, 2007 4:25 pm

Hi there

No, I wouldn't go near a BMW mini. I mean the A-series - I think this model is called "British Open" from 1992. Apparently the water pump has recently been replaced, but the rad cap has rusty streams leading down from it, so I think it's been under the care of a "specialist" who is letting it lurch from problem to problem and trousering £250 a time.

Mind you the owner is no help - "Oh I just keep on filling it up, I'll chuck some radweld in it soon, be all right.."

I sent her off with a long shopping list of de-ionized water, radflush, coolant, thermostat, rad cap, and told her not to touch it until I saw it.

Thanks guys

O

Stewart (oily!) · Post by **Stewart (oily!)** » Mon Apr 16, 2007 4:33 pm

At least the head gasket is ridiculously simple to do

Stewart

tom · Post by **tom** » Mon Apr 16, 2007 5:11 pm

Right Oscar. Standard head gasket test, followed by replacement of rad cap. Check the cooling fan rotates if it is a front radded beast and then check the switch and stat. It won't be anything else, I'm sure. The a series is beautifully simple and a head job can usually be done without skimming in about an hour.

mountainmanUK · Post by **mountainmanUK** » Mon Apr 16, 2007 5:41 pm

Core plugs??

M · Post by M » Mon Apr 16, 2007 7:43 pm

I wouldnt mind betting the rad is silted too. Fairly eary to replace, though access to teh bottom hose can cause bouts of swearing.

Oscar · Post by **Oscar** » Wed Apr 18, 2007 9:05 am

Well, we were all right.

Bottom hose collapsed; at least one leak somewhere on the engine block - I think where the bottom hose connects; a silted rad; an original so therefore probably knackered thermostat; thermostat bolts seized; "coolant" the colour of rust; airlocks.

A sorely neglected cooling system that had thrown in the towel.

I told my friend to take it to her "specialist" for a quote on a complete refurb of the cooling system. I don't mind lending a hand, but there was a couple of days' work on this.

It's not a mini adventure.

DavidRutherford · Post by **DavidRutherford** » Wed Apr 18, 2007 10:08 am

Oscar wrote:I think it's been under the care of a "specialist"

Therin lies half the problem methinks. Why on earth would you need a specialist for a Mini? Every mechanic in the world can work on a mini, they are possibly the simplest and most basic car around. It strikes me that this "specialist" is very good at being useless.

A new rad&cap, thermostat, both hoses (if one's gone, the other's on it's way) core plug (I bet I know which one it is that's gone) a flush and some fresh coolant will see that car another 15 years no doubt.

And all that should cost well under £100. Parts for minis are irritatingly cheap.

Oscar also wrote:a couple of days' work on this.

Aside from the siezed thermostat bolts, that's about 3 hours work... really.

Doz · Post by **Doz** » Wed Apr 18, 2007 10:10 am

Bypass hose ..... ****shudder****

tom · Post by **tom** » Wed Apr 18, 2007 10:37 am

Bypass hose is easy. There is a dodge we old timers used that made it a ten minute job. As for the core plugs, I've seen more than one sealed with a big self tapper and some addlerite. Silted rad is much easier on a Mini (They are a doddle to flush unless the car has been run on radweld) and hoses are not a problem. Air locks are unheard of. Worst job is the stat bolts. Prepare for the drill to wander when you drill them out. Parts cost is minimal and if the mini is a good one, then it is well worth it.

Oscar · Post by **Oscar** » Wed Apr 18, 2007 10:53 am

It's a good one and worth saving.

Also probably not worth letting the "specialist"at.

Which core plug? and what is a core plug?

And what's the dodge?

jeremy · Post by **jeremy** » Wed Apr 18, 2007 11:14 am

I don't think 1300's (1275cc) have bypass hoses. Its the little hose going upwards from the water pump to the cylinder head under the thermostat. You can buy concertina hoses from accessory shops that can be fitted without trouble - BUT some are unre-inforced and I had one go after about 6 months.

Core plugs are the smooth metal discs which fit in the cores (holes in the block casting where the inner part of the mould was attached and the resultant sand was shaken out.) BMC used domed metal discs which were expanded in position by striking hard with a hammer. Difficult to re-fit with the engine in the car as you can't get a good swing on them - but you may be able to do them with a plug. I seem to recall one up behind the flywheel!

In my view they are best left alone unless they are leaking, in which case - araldite or whatever may work to seal them. Using anti-freeze should reduce corrosion and prolong their life.

M · Post by M » Wed Apr 18, 2007 11:21 am

tom wrote:. As for the core plugs, I've seen more than one sealed with a big self tapper and some addlerite.

Or a two bob coin* and some "chemical metal" as I did on an ADO16 once

*Younger listeners may wonder what one of these is, its a proper 10 pence piece when money was worth something and we still had ha'pennys and you could buy two blackjacks for a penny.....Ahh jumpers for goalposts, whatever happened to Laskys etc etc