17 replies to this topic

[powermadcoop]

Mini Cooper SPi
1992

Hi

After travelling to Birmingham the other day from Halifax (about two and a half hours with no stops) after getting out of my car i realised that my overflow pipe from my radiator had chucked out some larrrvly brown coolant.

All the way down the motorway at about 90 my temp gauge sat mainly in the top of the white line

The only other thing i noticed is that my heater ocassionally blew cold

I could do with a coolant change anyway but is that all it might be? I dont want to keep driving it if its potentially a head gasket. I know minis arent prone to HG failure anyway but I tend to be having some bad luck recently with one thing and another!

There no funny smoke from the exhaust apart from a tiny bit on startup sometimes but i just put this down to condensation in my exhaust? and no mayo in the oil from what i can see.

Just looking for ideas on other stuff I could do whilst im working on it this weekend.

Cheers

Joel

[WiredbyWilson]

sounds like an airlock it the heater is blowing cold.

have you disturbed the system lately? top the rad up and run the car with the heater tap open and make sure the air gets warm. don't put the rad cap back on and keep an eye on the water level.

[Ethel]

It needs some water in it. If the water level is too low to cover the temperature sensor it will read low. The heater blowing cold is a sure sign things aren't well. Hopefully there's no permanent damage, A Series lumps are cast iron so tough as old boots compared to aluminium heads 'n blocks. Keep an eye on the water level, you may need a new radiator cap - and a head gasket if you've been unlucky.

[powermadcoop]

the rad cap is fairly newish and its not been touched. the water level is over the fins too in the rad so its not too low.

Ill just run it up to operating temp with the cap off and see how it goes from there!

[Disco Dan]

I'd make sure you dont have any leaks - also check to make sure your heater tap valve on the block is working correctly. And as others have said, check your fluid - even when the water is above the fins you can still add more to it before it rises!

[powermadcoop]

ive always got the tap open and taken the cable off of it. the pipes to the matrix always seem hot too but it blows hot and cold itermitently

ill give it a really good flush this weekend as well as running it with the top off tonight

Joel

[taffy1967]

You might need a new thermostat too.

[M44K TS]

could be a water pump problem, if it's not pumping round the water, the matrix will blow itself cold, the engine block will boil the water and generally not be a good mix. i think if you remove the top hose with the radiator full, it should start and pump through the water out of the top hose, which should mean the water pump is ok.

[Ethel]

could be a water pump problem, if it's not pumping round the water, the matrix will blow itself cold, the engine block will boil the water and generally not be a good mix. i think if you remove the top hose with the radiator full, it should start and pump through the water out of the top hose, which should mean the water pump is ok.

That makes sense, if there's ample water it will circulate through the heater regardless of what the thermostat is doing. If it's being blown out of the overflow then the water is getting hot enough to boil off, even at pressure.

[taffy1967]

could be a water pump problem, if it's not pumping round the water, the matrix will blow itself cold, the engine block will boil the water and generally not be a good mix. i think if you remove the top hose with the radiator full, it should start and pump through the water out of the top hose, which should mean the water pump is ok.

That makes sense, if there's ample water it will circulate through the heater regardless of what the thermostat is doing. If it's being blown out of the overflow then the water is getting hot enough to boil off, even at pressure.

Then how come on 2 separate occasions (with a previous Mini and my current Mini) did changing the faulty thermostat cure a cold blowing heater?

Previous Mini had the heater tap/valve on the cylinder head, whilst current Mini has the later MG Metro type set-up.

Edited by taffy1967, 13 August 2008 - 06:27 PM.

[M44K TS]

well i didn't say it WAS a water pump, just a possibility, thermostat would be my first port of call as they're sub £5 i think

[taffy1967]

well i didn't say it WAS a water pump, just a possibility, thermostat would be my first port of call as they're sub £5 i think

I was replying to what Ethel said.

[M44K TS]

ahhhh lol i see

[bananaman]

Run your engine until it's hot, hopefully the top of your radiator will heat up once the thermostat opens, then switch off and feel the bottom of your radiator, that should be hot too. If it's not, then possibly the thermostat, maybe a blocked rad. I'd give it a good flush through (backwards will flush out any debris sitting in the system)

I tend to take my radiator out when I do mine, and give it a good once over, make sure the gills are okay and not blocked with dead flies or anything.

This may sound silly, but make sure your fan is in the right way, it goes smooth side to the water pump. It still blows air the wrong way round, but it's terrible ineffeciant.

Plus, if your coolant is rusty looking, it needs a change and a flush through anyway, this should improve things no end.

[powermadcoop]

cheers for this.

stat should be fine as my top hose heats up once im up to operating temp

also had a new water pump 2 years ago with the larger impelor (if thats how you spell it) whoch does work as most of the time it doesnt do this only on LONG motorway jourmeys

Fans deffo on the right way round too.

so if i rule out the above its just down to crappy water and possible blockage.

it is just propper brown. probably due to two years of only ever putting water in it and no coolant!

its funny how us mini users have problems with one rad! my mates got a focus RS and thats got FOUR! (to quote jezza on the veyron)

thats nearly as many as my house!