Hello,

I have a 2003 Cooper S with 145k miles on it, and for the month I have owned the car, I have been using up a lot of coolant.

I had to replace the expansion tank just after I got the car, but I am still having to replenish the coolant fairly often, at least once a week.

The car does not smoke or have milky oil, so I am pretty sure head gasket is good to go.

I dont always see fluid on the ground under the car, when it does appear, it seems to be dripping off of the heat shield almost under the middle of the car, not under the engine itself. So where could the fluid be coming from? I cant see any leaks on the hoses or radiator. I have read that the thermostat housing or possibly the oil filter housing gasket might be my problem. Is there a good way to check what might be leaking? Or any other suggestions?

I appreciate the help. I just want to drive my car and not worry about my coolant level all the time.

 

I had thought I had a leaking thermostat housing. I thought I would have to put the car into service mode and take a lot of things apart to even get to where I could see it.

I discovered that by simply removing the tube that goes from the air filter to the throttle body that I could reach across and touch the thermostat housing, it was dry.

Also you can get a hand pump to screw on to the expansion tank, pressurize the system and look for leaks without burning your fingers.

 

I'm guessing when you say heatshield middle....you are talking about the backside of the motor...
That is where the oil cooler lines are (there is a coolant/oil loop) are located... Might have a failing gasket on it.....

 

I have found the source of the leak, it is the lower of the 2 lines going into the fire wall and the heater core. I have the lines on order, and will hopefully be able to change them with out too much hassle. Will let you know.

 

I was going to replace the thermostat gasket this afternoon, but when I got everything out of the way so I could see housing, it was dry. I could not find any sign of leakage, but it looses about a quart every few weeks.

I topped off the reservoir and will start putting it up on ramps every couple of days to check hoses that you mentioned.

 

The lines only leak when the car is warm, and its not a ton of fluid, so just keep that in mind when you check yours.

 

I am also having trouble with a leak in the the same place as the OP. I am suspecting the lower coolant tank hose, but haven't been able to confirm. It only leaks when I fill up the overflow tank - once that is empty it seems to stop and I never overheat even in summer.

I'd be curious if the OP ever solved his/her problem by replacing the heater core hoses? Mine is a 06 S.

Thanks!

 

I replaced the heater core hoses, only to find that the metal line that the hose connects to was damaged. I am waiting on parts to replace the metal line and then will hopefully be done chancing coolant leaks for a while.

If its your lower tank hose, it would be easy enough to change, I have had most of the system apart by now, and the only pain in the *** lines are the ones by the firewall.

-Kevin

 

That was quick! Thanks, Kevin, for that additional information. I will be taking a look at mine this weekend - keeping my fingers crossed it's not something that will take me all day to fix.

The hose I suspect is available from ECS for $39, so if that's it I'll consider myself lucky.

Wylie

 

No problem. I will have pictures posted once I get all the parts and get everything fixed. I am also looking at running a temporary fix by rerunning hoses and cancelling out the heater core all together until I have the parts on hand to fix it.

Kevin

 

Ok, so its taken longer then expected to get a chance to fix everything, but I finally got around to fixing the coolant leak in my car. The issue was one of the metal lines starting at the firewall and going into the heater core.




This is the reason its taken so long to do work to the Mini, I just got this in from the UK.

 

Is that a Triumph Vitesse? Neat car you sure don't see many of those about. How about some more info on your Triumph?

 

Yes, it is a Triumph Vitesse. And yes, it is right hand drive It is a 1969 mk2 Vitesse, which means it has the 2.0L inline six rather then the 1.6L. It also has a revised rear suspension compared to the mk1.
It is a numbers matching car, with 65k miles on it. The front brakes have been upgraded to drilled and slotted rotors, with stainless steel lines all around. It is a 4 speed manual with no overdrive, but cruising at 60mph is no problem.
The only things I plan on doing to the car are, suspension work, a hotter camshaft, and exhaust system, and new carbs. That will put me at about 150hp and should make it sound even better then it already does!