Using off the shelf stop leak solutions?=problems?
 

Ok here is the dilemma, been getting highly stressed over a mystery coolant leak on my 3.0D e53 2004 X5, should I use off the shelf stop leak solutions? Will it cause any problems trying?

My coolant level rod drops from MAX to halfway between MAX and MIN after say 550miles /900km of combined driving bit of town and highway….cannot see any visible leaks, think I bled the system ok last time I topped up..and even though the amount I top up is just half a small cup full, I don’t want to have to top up every 1000km.

Hmmm and doing compression checks worries me cos I don’t wanna hear it is a gasket or head/block issue, not on a car like this.

Any ideas from any bmw persons out there would be great?can I mess up the x using these things?

ps got a slight hiss when i opened the coolant reservoir cap last time, if it is trapped air how can air remain trapped yet coolant be lost?don't understand?

My advice is not to add leak stoping products... they can clog the ducts inside, hence stop the cycle and cause you to overheat. it happened to me with my old pathfinder... you will have to flush the system and clean it out again...

The solution to your problem is pressurize your system to find out where the leak is, and then either weld it (if the radiator is punctured), or change a possibly old hose... and if it is more serious, then what can i tell you? yuo have to do it anyway... not seeing a risk doesn't mean that it does not exist... take it from a risk manager :)

you can't see the leak, cause it is minimal, and it tends to evaporate on the high temperature...

about the hiss, leaking occures at very high pressure, and in a matter of few drops, so of course the system still builds pressure like normal systems, and the vapor is still formed and trapped...

good luck with the repairs...

Guess you are right, well gonna keep an eye on it, do have a weird feeling it maybe leaking near the webasto auxillary heater as the area on the body work near one hose that feeds the heater is slight rust coloured.thanks for the feedback