LJTX545I

Over the past month I started to get low coolant level warnings. At first I thought it was maybe due to the cooler weather, so I just topped it off and drove on. 3 weeks later, the light came back on and I added more - not more than a pint each time. Last week I had to add coolant twice - and now the leak is more obvious. I scheduled service for other more routine maintenance next week, I need to see what I can do to keep driving until I can get in.

thanks for your help.

LJTX545I

For starters, anybody know what am I going to find there once I get under the cover plate over the radiator?

luigi524td

Might help to know what e60 you have, its age and mileage.

Coolant leaks are nothing to fool with. Might be a simple hose or clamp letting go or something more testy like a failing water pump ... or worse ...

gatemaster

04/545/Step/SportSusp
I have 2 leaks, 1 is coolant, 1 is under transmission oil pan.
Suggest you try to unscrew the 2 fasteners that hold down the expansion tank in the engine bay (open hood, look to the left where the expansion tank is located). The expansion tank can then be pulled straight up, check the hose clips as you pull up and un-clip until you can lift out the expansion tank. The tank has a "hollow" corner when viewed from the bottom (use a mirror) which is where the overflow drains out. If you have a crack in the expansion tank or a cracked hose near the tank, you will see it. In my case, i am thinking the expansion tank cap (i use to call it the "radiator cap") is not holding pressure.
BTW, if you remove the forward debris shield and 2 more 8mm screws in the wheel well cover, you will see the bottom of the expansion tank, barely. You will also probably get an eyeful of coolant so wear some glasses, etc. My guess, it could be: leaking hose, cracked expansion tank, or expansion tank cap. realoem.com has the parts & prices.

Don't know about the source of my transmission leak, going to independent shop tomorrow.
I dropped the 2piece debris shield to track where the leaks are, the vehicle height makes all under-vehicle work a pain. Using blocks under the wheels to get minimal access.

good luck, mike

LJTX545I

Thanks.

Here's what I found under the hood latch holding cover (for lack of a better term). It wasn't broken like that until I pulled up on the tube, of course, but it was cracked.

LJTX545I

So the guys at work helped me change it to a stainless tube. Pretty easy fix, fortunately. If this does not solve the problem, I will have to check under the reservoir, but since the coolant had pooled near the top I think this will do it.

jelski

got also water coolant message since last week. looks like i will be screwing off some parts tomorow and hope to find the same problem. i have droven 96000 km btw with my car.
like this this forum is quite usefull

LJTX545I

Just some additional info. My car is almost to 66000 miles. I've added nearly 14000 miles since purchasing the car in July. This is an 05 545i. Most of my driving is on the highway.