Hi I have a quick question about topping off the coolant system. My manual says “The coolant is correct when the upper end of the red float is at least even with the upper edge of the filler neck, but no more than .8 inches above it - that is, up to the second mark on the float.” My mechanic told me if you overfill the coolant system it will just spit out the excess coolant like a baby drinking beer… Every 3 months my car’s coolant level goes from max of the float to min of the float and I’ve been topping it off with a cup of coolant/water to bring back to max. So the question is do I have leak or is the coolant system getting rid of excess coolant to bring the float back to min?
Also another question… how bad is it to overfill the coolant system by a little bit?
If it is spitting out the excess, don’t fill to the max the next time it goes to the min. Check it in a month. If it doesn’t go down, just leave it and don’t add any more.
If it does go down, you have a leak somewhere. If you can’t see a leak, it might be a leaking head gasket letting it go out the exhaust.
@Mustangman Being a computer tech should have got that one Thanks. How bad is it to overfill the coolant system by a tiny bit? Like maybe what would be a quarter inch above the max?
The cooling system shouldn’t lose any coolant. If it does and you can’t find any leaks the pressure cap on the reservoir may be weak and allowing coolant to escape as a vapor.
All good advice from all of the above posts.
I know this is common sense, but I will mention it anyway. when checking the level check it when the engine is cold. If you check it when it’s cold and then latter check it when it is hot you will get 2 different measurements.
And at 23 years old you’re right to keep on top of your car’s cooling system, BMW cooling systems need more care (read parts replacement) than others, including water pumps, radiators, etc.
It’s a little tempting to throw the whole cup of coolant/water in because where else can you put it? Mine’s ethylene glycol not propylene (most are propylene right?) so I’m not supposed to throw it anywhere convenient… definitely not driving to the dump or wherever to just get rid of a little coolant.
Most any shop or auto parts store will take it off your hands, or just flush it down the sewer system, just not out in the yard or storm drain… check local laws to be safe…
Why not just put it back in the jug it came out of???
My 2012 Camry stays just below the cold level and will spit it out if I add any coolant but never drops below that position if I don’t add any coolant and has done that since new.
The factory marks are not always exactly accurate. The book says my car takes 4.7 qts of oil but it always takes the full 5 quarts of oil to get it to the full mark on the dipstick.
Thanks. How bad is it to overfill the coolant system by a tiny bit? Like maybe what would be a quarter inch above the max?
