russlan44

i got a weird slow coolant leak from both sides, checked my hoses none of them have any drops, recently started drops in garage, hope its not my radiator, but looks like it is, anyone else gets this?
07 525
auto
58.xxx

sam.s

I'm getting a leak somewhere as well. I had the radiator completely replaced a few months ago but it is still leaking. The dealer doesn't know where the leak is. I'm having to add around a litre of coolant every 3000km. The underbody cover is pooling with leaking coolant but none of the hose is wet. It's odd as I'm not sure where the leak is and what needs to be replaced. I've had this problem for over a year now. Even independent BMW shops don't know how to fix this.

inktoxicated

ur radiator is shot, most likely the fins are corroded and cracked. same thing with mine at 50k buy a behr online for 200 and u can install it with a freind in a few hours

http://forums.bimmerforums.com/forum....php?t=1709606

calvillor

its from your temp sensor, I bought a new radiator and didnt have to use it, buy a new temp sensor and ir will come with a new O ring, that is where its leaking from.

sam.s

Is it possible to just buy the o ring or would I need to replace the temp sensor as well? Also whereabout is the sensor, is it in the engine block or the radiator? Thanks

pcy

temp sensor is attached to the hose (lower radiator hose, on the passenger side). You can buy the o-ring separately.

I went thru the same song and dance... replaced o-ring, then the temp sensor, then the hose, then the radiator. What's your lesson from my experience? :-)

reflection

perhaps its the pump? in my case it is

rockabilly_Drummer

i have a 2006 530i, it has a small leak on the drivers side, i cant see where it is originating from. all the hoses look dry and in good condition, i figured it is the rad. i have bought a new one and am planning to install over the holidays but im debating whether to replace the water pump and expansion tank while i'm at it (my expansion tank float broke off) obviously i dont want to spend $$$ on replacing parts that are perfectly ok, but reading some forums and people who have had radiator trouble say they end up doing a complete cooling overhaul. Any suggestions anyone has would be gratefully received. if i do go with a complete overhaul what else would i need to replace?

pcy

Before you replace any part, you need to identify the source of the leak. There is a thin hose at the top of the radiator (that connects to coolant reservoir). That thin hose is known to leak.

Coolant reservoir is not that expensive... around $40. Your car has an electric water pump and it's little over $300.

rockabilly_Drummer

the coolant res. it on the passenger side, this leak is appearing on the drivers side under the auto. trans. cooler area.. i cant identify where the leak is originating from as all hoses etc appear to be dry. thanks for the input tho.