Missing Coolant?

[hoe3]

My 93 325is is losing coolant somewhere. The CHECK COOLANT message pops up when I start up the engine and then goes out. I cannot find any leak anywhere and there are no puddles of coolant under the car after being driven or after sitting over night in the garage. Last nite I filled'er up to the Full line, let it run a few minutes sitting, and turned it off for the day. Next morning, starting up the engine, CHECK COOLANT message appears again and goes out. I checked the level of coolant and damned if it isnt way below full again! After driving the car I checked under the hood for any signs of leakage and find NOTHING! Does anyone have any idea of what is going on here? I have about 120K miles on the engine. Performance is normal and I dont get any engine overheating messages. The dash gauage always shows the needle right smack in the middle where it has always been. I am not a mechanic (you guessed that already) but I know this is not right. Ideas?

[MT-2500]

Originally Posted by hoe3

My 93 325is is losing coolant somewhere. The CHECK COOLANT message pops up when I start up the engine and then goes out. I cannot find any leak anywhere and there are no puddles of coolant under the car after being driven or after sitting over night in the garage. Last nite I filled'er up to the Full line, let it run a few minutes sitting, and turned it off for the day. Next morning, starting up the engine, CHECK COOLANT message appears again and goes out. I checked the level of coolant and damned if it isnt way below full again! After driving the car I checked under the hood for any signs of leakage and find NOTHING! Does anyone have any idea of what is going on here? I have about 120K miles on the engine. Performance is normal and I dont get any engine overheating messages. The dash gauage always shows the needle right smack in the middle where it has always been. I am not a mechanic (you guessed that already) but I know this is not right. Ideas?

First thing make sure no coolant is getting into engine oil or transmission fluid.
Any blue smoke out tail pipe or engine miss when first started.
Any coolant leaking into the floorboard?
Is coolant geting low in overflow tank or radiator or both?

They make a leak dye to put into coolant for them hard to find leaks.
Most repair shops have a pressure tester they can run on rad to find a slow leak and see if system is holding pressure.
Also if no external leaks can be found a head gasket test may be in order to.
http://tools.batauto.com/index.php?c...on=show_detail

The pressure test should be done on a cold engine then warmed up part way then checked hot.
I have saw a rad and other stuff leak at a certain tempture and not a other times.

[hoe3]

MT-2500 Thanks for the reply and suggestions. I will have to check the oil and tranny fluids as you suggest. No blue smoke or engine miss that I notice. No fluids on the floorboards. I am having to fill the overflow tank up to the Full line when engine is cold. As I said before I do not notice any performance problems with engine at any speed. It just runs like it always has. I have owned this beemer since it was new in 1993 and it runs the same today as it always has. I would think if I had a compression leak or bad head gaskets it would show up under the driving load.

Guess I better get it in to the Stealer to see what is up. Thanks!

[MT-2500]

Originally Posted by hoe3

MT-2500 Thanks for the reply and suggestions. I will have to check the oil and tranny fluids as you suggest. No blue smoke or engine miss that I notice. No fluids on the floorboards. I am having to fill the overflow tank up to the Full line when engine is cold. As I said before I do not notice any performance problems with engine at any speed. It just runs like it always has. I have owned this beemer since it was new in 1993 and it runs the same today as it always has. I would think if I had a compression leak or bad head gaskets it would show up under the driving load.

Guess I better get it in to the Stealer to see what is up. Thanks!

Well good luck.
Coolant leaks can be a pain to find at times.
Someone that works on that car and engine all of the time may know just where to look or check on it.
And head gasket can leak about 10 different ways.
The pressure test and adding dye to coolant and head gasket test is the best tools I know of to find them.

I have had some just leak at one certain tempture or just when the want to.
MT