gretamay

I've got an '04 545i sport with 80K on it. My records with BMWs began with E3, E12, E23, E28, etc. so I am a fan of the manufacturer. I perform all of the service myself at 1/2 the intervals specified by BMW. My problem is that I have a recurring coolant loss. I've replaced the reservoir and all of the hoses, and there is nothing in the oil. I cannot find any evidence of a cracked radiator but occasionally I get a squeek from what I think is the water pump. I don't want to start a massive part swap trying to find the problem and would rather focus on the problem itself. Has anyone got a similar situation, or perhaps, guide me to a probable cause?

bahamutzyro

i have an 04 545i. i just took my car to the dealer because i got a low coolant warning. i then put some coolant in the resevoir. the next day the reservoir was empty. i took the car to the dealer as its cpo. the service rep said that its probably the overflow reservoir. i dropped it off on thursday 2/25/2010. still havent gotten it back or a phone call. the brightside is i got a 2010 335i xdrive fully loaded loaner so i dont care how long they take!

miguex

it might be O-ring problem! you better pray it is not because it can bring your car on major repair for just replace the O-ring.

See this: https://5series.net/forums/topic/937...st__p__1109003

See this video for the solution (around $1600 and much better than $5K that most dealers do)