16 replies to this topic

[Geordie Skydiver]

Ok, so my 1295 stage 3 mini has 3 rads, the normal side mount, a small front mount and another small side mount, i've just reassembled the engine after a head skim, and it ran quite hot on its first go, but only two of the rads had any heat in them.

Is the water pump not up to the job?

Is it possible to fit an secondary external water pump?

The 3rd rad is after that heater valve thing, could that be facked? (it leaks too... so I guess it is buggered)

I need to keep this sucker cool, thats reason I had to skim the head in the first place...

Any suggestions?

[Sprocket]

Suspect there may be a few things here.

I'll start by saying that there should be no need for this many rads on any 1293 in any state of tune, a standard rad should just about cope, even more so in this C**p weather we are having. They may actualy cause over cooling when you finaly get the system working. Just to make you aware.

Having said that, the extra rads you hvae may well be air locked and hence no circulation. Also note that there is only one way the fan should be fitted to the engine, the fans has 'engine side' stamped into one face of the center and should be fitted as such. What water pump are you using and with which size pulley, the pump to use is the 'large' cast impellor one and the large pulley. Is the thermostat fitted the correct way up. Has the main rad been back flushed??

Hope this will give you a few more ideas as to where to look for the problem.

[Bungle]

you can get a replacement electric water pump

[Dan]

Good god do you live in the Sahara?
There is just no need for that much cooling, a standard size two core rad or an aluminium replacement will be more than adequate.

Is the heater valve open? If not water won't be getting through it.

[miniboo]

have you got a pic of this crazy overcooled mini?

[nev_payne]

Surely a 4 core and a 13row oil cooler surfices the needs of a 1293??? if it was a 1400 or a vauxhall/v-tec then yes you have a valid point.

[Clubby1275GT]

u may aswell encase ur 1293 in your home freezer and put that one wheels!

[Geordie Skydiver]

Woah there tigers, I didn't design it, I bought it like that.

It seems one of the smaller rads is the heater matrix, but the valve is knackered I reckon.

The fan is a seperate electric one with its own swtich, there is also a digital temp gauge with the temp sender mounted onto the top of the thermostat housing.

When I bought the car the top rad hose was 3 ft long (i'm not kidding, it was coiled up under the bonnet) and the standard rad wasn't bolted in. I've refitted these as they should be.

I don't know what water pump is on there.

I only ran it with water in, no coolant as I wanted to check the plumbing before I did any real driving.

It doesn't have an oil cooler.

I'll try and get a picture to post up, I'd like to get this sorted and maybe ditch one of the smaller rads, there just isn't much room under there.

[pikey7]

honestly mate, dump all those non standard ones. From the sounds of it they are just more hassle than they are worth.

A standard rad does the job adequately when in good nick. a 2-core one is better. Just make sure your pump is good (if you're unsure, they are only £15-odd), the thermostat is good and is the right value, and your hoses are in good nick and you won't have a problem.

It'll save you about 20kg on the front end too!

[Jammy]

As Pikey says, ditch 2 of the rads! Even the standard rad was ok on my 1425 during the summer! I simply swapped to one super cool 2 core rad from MiniSpares because I got paranoid! lol

[Dan]

The sender for the temp gauge being in the top of the thermostat housing will stop it working. It won't get exposed to any hot water until the thermostat opens and it will probably close again before the sender has reacted fully so it will always read cool. The sender needs to be before the thermostat, like where it's supposed to be as standard.

Get a mechanical fan back on it, Mini's need one even if there is an electric fan as well.

Ditch both the auxiliary rads mate, they are rarely needed on road going Mini's and a two core rad works a lot better (the two core cools better than the old 4 core by the way).

[Purple Tom]

also while you're fiddling about with fans and radiators, fit the uprated deep impellor water pump.

I installed my 1293 in a bit a hurry last year, and all I could get at the time was a crappy Halfords water pump. It ran really hot in Germany,up into the red on occasion - when I got back I bought the deep impellor pump and the difference was startling, cools so much better now.

My 1293 just has:

Cast deep impellor water pump
2-core 'super cool' radiator
New hoses
Flushed heater
50/50 coolant/water mix
Switchable electric fan (only just fitted that so never driven with it yet).

Plenty of cooling.

[Geordie Skydiver]

The sender for the temp gauge being in the top of the thermostat housing will stop it working

It works fine, the standard one is still fitted and works fine, this one just gives an indication of the temp of the cylinder head, its not even plumbing in, just bonded to the outside of the thermostat housing.

For now then, just to get the car running and MOT'd etc I'm gonna do the following.

1. Ditch 2 small rads.
2. 50/50 mix.
3. Have the electric fan running constantly. (unless its seriously cold)

Does this sound reasonable?

In the future I'll probably fit the better water pump and a newer main radiator, if I don't sell the car first. All the hoses are new anyway.

Thanks again for the advice.

[Dan]

It's not an air cooled engine, the cylinder head temperature will be nearly the same as the main coolant temperature. And it's still only giving you the coolant temp if it's on the thermostat housing. Keep it if you like it but it's not actually doing much.

I'd still be inclined to fit a mechanical fan. Nothing can go wrong with a mechanical fan other than total failure of the blade. The electric fans aren't designed for continuous duty, the motor might fail at any time if it's running permanantly and then you'll be screwed.

You may well have a good water pump anyway. The deep impeller version isn't actually uprated, it was standard for lots of 1275's and all injections. It's just that as standard it has a well made cast iron impeller whereas the cheap parts shop ones have a pressed steel impeller which is much less efficient. These have been fitted to lots of cars and are pretty rubbish.

[Purple Tom]

just do you can see the difference between good (on the left), and bad (on the right) when it comes to water pumps....