very slow water leak?
I recently bought a 1995 bmw 540i and have done a few things to bring it back to par.
However, I have been having to add some Prestone 50/50 to cap off the fluid. It is such
a small amount each few times I drive it in the very hot Oklahoma summer that I have
not been too worried about driving it. I watch the temperature gauge closely and it
never gets hot. The add coolant light comes on every few days. Since this is my first
BMW of any vintage I would like to know if this is normal or should I take it in for a
system pressure check to find where the fluid is going or should I wait for the fluid loss
to get worse so I can determine for myself a needed repair. This may sound silly but I
fear sometimes that a repair shop may find a minor problem but tell me I need some
major work. I feel if I wait the fluid loss will become apparent. I am not the least
mechanical and am a pessimist when it comes to auto repair shops. Is there an easy
way for me to determine such small amounts of fluid loss?
Places like auto zone have a kit to pressurize your cooling system so you can find the leak. They don't charge you to use it.
The BMW's don't have much coolant capacity and your flirting with having your system fail on you. If you have anywhere near 100K, it's time to replace your coolant system components suspect your coolant tank is leaking. Replace all the components in the coolant system and you should be good for another 100K. Go to this link and scroll down to coolant system......http://www.bimmerfest.com/forums/showthread.php?t=525152
Be sure to take your BMW to a shop that specializes in imports or your local BMW dealer. Your average local garage or auto repair place won't know much about your car. My Nephew found that out the hard way with his '98 528i. HTH. -Jim
BMW uses cheap plastic components in the cooling systems of most of their cars, which require complete overhaul every 80k or so. You could just track down the part that needs replacing, it usually start with the expansion tank, or one of the hoses, but you will end up replacing everything because the plastic just rots as it ages. I own an E39 540(1997-2003), it is not too similar to the E34(1989-1995), but they share a lot of issues with each other, overheating is the #1 killer of V8 E34/E39, if you enjoy your 540, this is something you want to take care of asap.
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