13 replies to this topic

[CharlieCroker]

Hello,
I took my newly purchased 1996 Mini Cooper 'S' to stanford Hall yesterday with the drive taking about 1hr 10 mins and in that time i never ventured over 70 MPH. Once we were in sight of Stanford Hall we hit a queue of traffic waiting to get in. It was at this point that my temperture gauge went off the scale, i managed to get in the grounds and park up. I lifted the bonnet and the radiator seemed to be boiling like a kettle, i went off and came back a few hours later to check the radiator. The water had not all dissapeared but there was a good 1/2 ltr gone.
Once i was ready to set off back home i topped the water up and put on a new 15lb radiator cap as the old one looked perished and made my way home again not going over 70 MPH, the temerture hit half way and stayed there all the way home with the radiator loosing only a little water.
My question is is this normal or do i have a problem with the car? I did ask someone at the meet and they said it might be the electric fan not cutting in when it should? how would i check this?
Someone else said it might be the head gasket but i hope to god its not.

Any tips or advice much appreciated.

Ash

[minidaves]

possible sticky themostat or bunged up rad, remove stat do a proper rad flush, fit ned stat and then fill with new antifreeze,

dave

[mrslaphead]

Mines doing the same at the moment, and its the electric fan not kicking in.
On mine its corrosion of the wires going into the relay plug.
You could check the temp sender in the bottom of the rad is working or check the fuse.

Hope that helps

[bmcecosse]

It only heated up when you stopped - so yes - it's likely just the electric fan. to test it - replicate what happened before! Drive it hard - then sit idling for ages and see what happens.

[badlyspeltbouy]

I'd be careful, mine overheated as the electric fan didn't kick in and it blew the head gasket, warped the engine mounts and a ton more, was off the road for a few weeks. All better now though.

[bmcecosse]

" warped the engine mounts " ?????????

[taffy1967]

To test the electric auxiliary cooling fan (I am assuming it's a side mounted radiator on an SPi Mini Cooper as 1996 was the changeover year), whip the grille off and remove the 2 spade connector terminals from the lower front of the radiator.

Connect the spade connectors together with a paper clip and then switch on the ignition. The electric auxiliary cooling fan should then start blowing (keep your hands well clear).

If it does work, then the sender unit in the radiator may be faulty.

It it doesn't work (even if the relay is making a clicking noise), then check the in-line fuses behind the air filter box on the bulkhead.

I believe it's the in-line fuse with the 15amp fuse and the 'Blue/Red Wire' that you need to check.

Let us know how you get on.

Oh and you really need to fit a 15lb radiator cap with a rubber seal for an air tight fit, otherwise the coolant will escape: -

Click Me.

I believe Somerford Minis sell the seals separately?

Edited by taffy1967, 15 September 2009 - 10:55 PM.

[CharlieCroker]

To test the electric auxiliary cooling fan (I am assuming it's a side mounted radiator on an SPi Mini Cooper as 1996 was the changeover year), whip the grille off and remove the 2 spade connector terminals from the lower front of the radiator.

Connect the spade connectors together with a paper clip and then switch on the ignition. The electric auxiliary cooling fan should then start blowing (keep your hands well clear).

If it does work, then the sender unit in the radiator may be faulty.

It it doesn't work (even if the relay is making a clicking noise), then check the in-line fuses behind the air filter box on the bulkhead.

I believe it's the in-line fuse with the 15amp fuse and the 'Blue/Red Wire' that you need to check.

Let us know how you get on.

Oh and you really need to fit a 15lb radiator cap with a rubber seal for an air tight fit, otherwise the coolant will escape: -

Click Me.

I believe Somerford Minis sell the seals separately?

I tried the paperclip trick and yes the fan did start to work so does this mean it is the sender unit within the radiator? If so are these easy to replace and how much would one be?

Thanks for the help..

Ash

[taffy1967]

To test the electric auxiliary cooling fan (I am assuming it's a side mounted radiator on an SPi Mini Cooper as 1996 was the changeover year), whip the grille off and remove the 2 spade connector terminals from the lower front of the radiator.

Connect the spade connectors together with a paper clip and then switch on the ignition. The electric auxiliary cooling fan should then start blowing (keep your hands well clear).

If it does work, then the sender unit in the radiator may be faulty.

It it doesn't work (even if the relay is making a clicking noise), then check the in-line fuses behind the air filter box on the bulkhead.

I believe it's the in-line fuse with the 15amp fuse and the 'Blue/Red Wire' that you need to check.

Let us know how you get on.

Oh and you really need to fit a 15lb radiator cap with a rubber seal for an air tight fit, otherwise the coolant will escape: -

Click Me.

I believe Somerford Minis sell the seals separately?

I tried the paperclip trick and yes the fan did start to work so does this mean it is the sender unit within the radiator? If so are these easy to replace and how much would one be?

Thanks for the help..

Ash

It could be the sender unit and if it's the original type then it just pulls out I believe? A replacement isn't too expensive: -

Click Me.

Mini Spares also supply a newer screw in type, but that's only compatible with the new type radiators they supply.

[CharlieCroker]

taffy1967 - you say the sender unit just pulls out, does the radiator have to be drained to be able to do this?

Also would you know how i would do a rad flush on the model of mini i have ? (1996 cooper)

Also i am reading a lot about putting antifreeze/coolant in the radiator, do you fillm up totally with this or add a bit of water as well?

Soz for so many questions but i am propper thick at geeting me head round this and i'm a proper mechanical novice as well!!

Cheers,

Ash

[taffy1967]

I believe it just pulls out (?) and the coolant does need draining first. Although I suppose you could drain it by pulling the temp sender unit out and using a bucket or something to catch the escaping coolant?

Failing that, you need to remove the bottom hose from the lower rear of the radiator by unscrewing the jubilee clip. It can be a pretty fiddly job, although I've heard there are other ways around it which I'm not too sure of myself.

Then after the coolant has escaped you can refit the hose (don't bother putting the jubilee clip back on just yet) and fill it up with just water or a flushing agent from Halfords or any motor factors and follow the instructions on what to do. Also make sure you have the heater tap open (pulled out) so the heater matrix gets flushed out the same time.

After you've drained the flushing agent, you'll need to refit the radiator hose again (this time refit and tighten the jubilee clip) and add a mixture of anti-freeze and water to the correct ratio. Some use a 50/50 mix or greater?

If you want to completely remove the radiator, then it can be a pain with your type as the expansion tank (which sits beneath the N/S inner wing) hose is near impossible to remove from in front of the radiator cap/spout. Don't try forcing it as you could snap the fixing itself. Removing the hose from the expansion tank itself is generally easier and then you just need to pull it's hose through the inner wing grommet and then leave it hang from the radiator.

After that you just need to undo the radiator bracket bolts on the top, plus the large securing bolt on the bracket at it's base and then carefully lift the radiator up and out of the car. It's not too difficult, but you have got the larger electric auxiliary cooling fan to watch out for and you really don't want to damage the radiators matrix/fins (or whatever their called).

Then you can flush and back flush the radiator whilst it's off the car.

[Pauly]

You may also need to replace the header tank cap aswell, otherwise the overheating will continue.

Paul.

[CharlieCroker]

Hello Paul,

What's that look like? ( header tank cap )

Cheers,

Ash

[Pauly]

The clear plastic tank at the top right hand corner, that cap loses its seal and causes overheating.

Is it a MPI or SPI. SPI have a side mounted radiator with a visable fan.

Paul.