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Mini loosing coolant!!

5K views 11 replies 8 participants last post by  TRISH66 
#1 ·
Hi i have a 2002 mini one and over the past few months its been loosing coolant. Ive replaced the filler cap on the expansion tank and the pressure cap which haven't worked. I've recently had the car in a local garage and theyve pressure tested it and said there's no leaks so it will more than likely be getting into the engine so will need a new head gasket which will cost around £400. Has anyone else had this? I've been filling the water up almost every day,the car doesnt run very well in the morning until it warms up. And after running for a while the engine smells very hot but the temp gauge only shows half way? Some info would be greatly appreciated thanks
 
#3 ·
My R52 started sipping coolant this spring and then went to gulping a liter or more a day. My shop replaced the thermostat and the housing and now she still drinks a little, but only on the hottest days. Seems to be a known design flaw. Have your shop look and when they can't find it tell them to drive the car for 45-60 mins then they should see the leak.
 
#3 ·
Before tearing the engine apart I'd make very sure you don't have any external leaks. Favourite places to go are the thermostat housing or the lower corners of the radiator. They're difficult to spot because it's fairly tight, add a dye to the coolant and check it that way.
A pressure test on it's own will not always show up a leak, it could be a hairline crack somewhere which only leaks when hot due to expansion.
 
#4 ·
This seems very common, i have just sorted the same problem and it was a combination of the 2 speed radiator fan not working at low speed and would only come on fast speed, the thermostat was not working properly slow to start opening and not opening very far causing lack of circulation and coolant boiling and loosing it through the expansion tank. Still not a cheap fix though, it may end up being the head gasket but i would want more than a guess if i'm paying

The temp gauge is very dumbed down and sits in the centre over a very wide temp range and if you see it rise further its getting very hot.

Do a search there is a lot of info about loss of coolant, coolant boiling etc

One thing i dont understand is if its had a pressure test and shows no leaks how can a garage say it must be leaking into the engine, check the dip stick and see what colour oil is, creamy colour indicates water in oil, thought a garage would know that, or if it was leaking into combustion chamber you would be followed by a cloud of steam
 
#5 ·
If garage cant find a leak after doing a pressure test did they do a headgasket test with a sniffer ? If it starts and runs lumpy first thing in morning and then clears after a minute or so then this is typical signs of water getting into bores overnight and burning off when started hence the lumpy/misfiring running .
£400 is well cheap for recplacing headgasket so id snap there arm off for that price !
 
#6 ·
Hi thanks for the input guys I'm really not sure what to do next other than buy some of the stuff to put in with the coolant to try and seal it, does anyone know what that stuffs like. I've heard good and bad things about it? I know that the fan does work as I've heard it come on once or twice, but only when it's been running for a long time. So not sure if that's the problem as if it didn't come on when it was supposed to the water would boil dry? Also I've checked the oil cap and dipstick, no sign of any gunk?
 
#7 ·
Another potential leak point besides the thermostat housing is the back of the water pump. Unfortunately, you will need to remove the pump to inspect evidence of leaking from 2 x drain points. Also, remove the S Belt and check for play in the water pump pulley as this can indicate if the bearing and or seal could be worn, on some models, the pump impeller also corrodes with resulting poor pumping ability causing the car to overheat. I can post pics later when I get home from work to indicate the weep holes on the water pump.

P.S. do NOT add any sealant to the cooling system to stop any possible leaks, this will cause more issues than it will ever solve. make sure you use the correct coolant with a 50/50 mix with distilled water, only ever use tap water in an emergency as the correct coolant 50/50 mix aids not only in cooling the engine but also minimise corrosion.
 
#10 ·
No, tap water will kill it more slowly. Your head gasket has gone. 400 is a bargain, does it include skimming? I just did mine and the machining cost me 170. If you want to keep the car bite the bullet and get it done, otherwise sell me the car and I will do it for fun! The reason your temp gauge is useless it that it is not a real gauge. It sits in the middle over a wide range of temps to keep people happy, drivers get freaked out nowadays if the gauge moves. It only moves to hot when you have no water left. (Ask me how I know!)

Gordon in Northallerton
 
#12 ·
No, tap water will kill it more slowly. Your head gasket has gone. 400 is a bargain, does it include skimming? I just did mine and the machining cost me 170. If you want to keep the car bite the bullet and get it done, otherwise sell me the car and I will do it for fun! The reason your temp gauge is useless it that it is not a real gauge. It sits in the middle over a wide range of temps to keep people happy, drivers get freaked out nowadays if the gauge moves. It only moves to hot when you have no water left. (Ask me how I know!)

Gordon in Northallerton
gordon any idea why my mini cooper is loosing coolant/water, ive changed the seals and 0 rings in the rocker cover and also changed the thermostat housing had the radiator changed and now found out i have a crack in the water pump .im ready to give up will changing the water pump stop it from getting very hot and loosing water?
 
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