14 replies to this topic

[Tonkleton]

 

Morning.....

please forgive me as i am not a technical person and i dont know an awful lot about cars...just that i love my mini!

Im currently driving a 2004 (54 plate) Mini Cooper that has done 87,000..... I brought this at the end of June and it has just gone back to the shop twice becuase it was overheating... The temp gage was peaking at the maximum and when i checked in the engine it looked as if there was no water in it and the lid had popped on the water 'tank'

the first time they replaced the 1st fan, i drove it home fine, no problems, drove it to work the next day - the same thing happened.... took it back to the place they said it was an airlock and not the head gasket etc....

i drove it to work this morning and it was fine - however when i checked the engine when i got to work - the water is empty - although the fan wasnt coming on and it didnt over heat.

The guy who fixed it told me that is an 'overflow' so it sometimes doesnt have anything in it, that it sucks the water out and pushes the water back in -  is this right?

 

I guess my question is should the place where you put the water and coolant in always have something in it - up to the fill here line or is this guy right?

 

Im concerned about driving it home if the same thing is gong to happen and its going to over heat?

 

Hope this makes sense

 

thanks!

[Alex_B]

The overflow should have water in it up to the minimum line otherwise you won't know how much coolant is in the car, I would be topping up and taking back to the garage to investigate where it's going, it could have a leak or it could be the head gasket letting water into a cylinder

[Tonkleton]

Thanks...... is this a bad problem....? should i top it up then see?

[Tonkleton]

Also the guy said to me it was an airlock......

[SecretSugar]

http://www.mini2.com...1611j1167675j11

 

Hope this helps :)

[jaydee]

I can bet its the termostat that needs replacement.

Also, you need to fill from the rad cap, but also need to fill up the expansion tank aswell

Edited by jaydee, 05 September 2013 - 09:36 AM.

[Ethel]

2004 makes it a Bini, it will fill via the expansion tank. 

 

An airlock would just mean there was air trapped in the system, possibly the heater, the circulating water should swap places with it so the air goes to the expansion tank instead. If that's the case you just need to top up the water. If the level continues to drop you're losing it somewhere, if the engine is getting too hot the filler cap lets the steam out, like the valve on a pressure cooker. So it could be overheating, or it could just be a faulty cap.

 

Alternatively you could have a leak somewhere else, if it's via the head gasket it sometimes shows up as a creamy coloured deposit in the oil filler, or by air from the cylinders pressurising the cooling system  before it gets hot - squeeze a radiator hose to test.

[Tonkleton]

is a leak a huge fault? should i keep topping up the water?

[Ethel]

It'd be worth fixing for the cost of antifreeze alone. Otherwise it depends on where it's leaking. A hose might not be so bad, though it's only likely to get worse, and if it won't hold pressure it will overheat & risk detonation -  melted pistons are defo not good. A leak at a gasket could result in erosion to the mating faces - expensive machining to make them flat again.

[jaydee]

2004 makes it a Bini, it will fill via the expansion tank. 

 

 

It wont fill via the expansion tank, you really need to fill up via the rad cap, you MUST fill it from the rad cap, and bleed the system via the three small bleeding valves in the system.

 

You really must have the thermostat checked, the old type white gaske cause this problem, try the later type with the grey gasket.

[cal844]

yeah thats correct Jaydee, fill the rad then bleed, then top up and fill the expansion tank?!

[Ethel]

I used google images to confirm the tank location, but Minimania's site does mention filling via the thermostat housing, but expansion tank on "S" models.

[jaydee]

Forgot how many times i've done this

I usually open the bleeding screws a bit then fill up from the rad cap, if coolant goes out the screws, close them gently (theyre made out of a very soft plastic) and fill the rad cap to the top. Fill up the expasion tank then. The still will be some little air in the system, so start up the car with the rad cap open, then slowly release the bleeding screws to let some air escape. One of the bleeders wont work until thermostat opens, i think its the one on the rad top hose. Close rad cap before car gets up to temp or it will spray all the coolant out like a nigara falls!

Use a 50% glycol ethilene and distillated water mix.

[jaydee]

I used google images to confirm the tank location, but Minimania's site does mention filling via the thermostat housing, but expansion tank on "S" models.

 

The rad cap is on the thermostat housing.

Wont work on Cooper and One models, and even the S models with pressurized expansion tank require the same filling procedure.

Although filling the pressurized expansion tank might work, i wouldnt actually reccomend that, you'll be letting way too much air enter in the system, binis can be a pain to bleed if filled up that way.

[jaydee]

is a leak a huge fault? should i keep topping up the water?

 

I wouldnt go for the costantly topping up option, best to fix it

Thermostat gasket fault is more evident with egnine cold. Another weak point to check is the rad itself, but 99% its the thermostat failing.

Try bleeding first, check all pipes and the rad, if still loosing water, then with engine stone cold, start up engine and look under the bonnet and under the engine, you'll see the thermostat dripping out coolant.

Once you're sure its the thermostat, replace the complete unit, not the gasket only.