Hi,

I own a 2006 Cooper S and my temp gauge has shot up to the max a few times so I brought it in to the dealer and turns out there was a leak so they fixed that, then a couple of months later, same indication with the temp gauge so I brought it again and I was told that there's no leak and due to evaporation, I just need to check my coolant and top it off when required.

So my question is, is it a common need to check and top off the coolant occasionally? If so, what is the procedure, just open cap and pour coolant fluid and close cap?

According to the mini manual, the coolant tank is sealed tight, so technically the coolant shouldn't be going anywhere even despite evaporation. I also though the coolant fluid just recycles so topping off isn't necessary, and my friends who drive other brands of vechicles just flushes every few years or so and never had to top it off once.

Any comments would be appreciated, I've never dealt with any car maintenance before

 

A small amount of loss is normal, but if you're topping it off every month or two, you've got a leak somewhere.

- Mark

 

Something to check is that your not overfilling the tank.

The tank should not be fuller than the minimal line when cold.
When looking into the tank should should be able to see the "shark fins" above the coolant level.
They should be just visible above the fluid level.

If you don't see them you've overfilled the tank and it will purge the excess through the cap.

I was forever re-filling my tank, I thought I had a leak, till I quit overfilling the tank.
I now go at least 12 months without adding any fluid and when I do add it's maybe an ounce.

Did the dealer do a pressure check as well as checking for a thermostat leak? If not they should.

Hope this helps...

 

Thanks for posting that kazlot. I've always had a hard time checking the level because for me, it is impossible to see the level through the tank to see if it lines up with the marks on the outside. Looking for the "shark fins" (good term by the way), makes it much easier.

Funny thing, my MCS came overfilled and I never saw the "shark fins". After having my thermostat gasket replaced due to leaking, the coolant was refilled to the fins and hasn't moved since.

 

I went through this issue as well. See this thread for more information on how to bleed the system.

https://www.northamericanmotoring.co...-resovoir.html

 

I have a small flashlight. When I check the coolant level [when cold], I remove the cap shine the flash light in the top and I can see where the level is. The only time I ever had to top off in my 06 S was when the thermostat housing started leaking - which is a common problem on these cars.