EddieboyS

Hi guys, have had a low coolant warning a couple of times in the past several months. Topped it up but can see no apparent leaks etc. Had my indie mechanic do a pressure test on the cooling system and he found no problem. At this point I'm hard pressed to understand what the issue might be. Has anyone seen this type of phantom coolant loss with their 550 or other e60 model?

Thanks, Ed

Isaiah_Charles

There's a coolant reservoir of some type behind the engine, hope it isnt that, GL..

JAYS545

There's a plastic tube under the radiator top bracket. Remove that metal strip and u should see it. That's where I had a leak. You can't see it just by looking at the engine.

ronmexico

Any ideas what the part is called? Or better yet, a part # ? I too am having this same kind of loss @ 90k.

jpar002

Had the same issue as JAYS545 on mine at around 90k. If I remember correctly, it goes from a 1/2" flexible hose to a rigid 1/4" plastic tube accross the span of the radiator. At the transition to the tube there is a brass fitting, mine had a hairline crack right there. I noticed it one day when I saw a tiny stream going down the radiator fan housing. I bought some 1/2" hose and a couple clamps and replaced the whole run to overflow tank.

E60I

I have the same problem right now. It's called the vent pipe. For an '06 530i, part number is 17127521775.

As an example, here is a link to part #4 : RealOEM.com * BMW E60 530i Cooling System Water Hoses

I am still waiting for my part to arrive. I wonder how long I can drive my car like that?

BimmerFan52

I repaired mine as I had the car apart while doing the water pump and thermostat and didn't want to wait for BMW to open to buy the part so I could close the engine back up.

On both ends of the center tube are flexible rubber tubes that connect to the radiator and coolant expansion tank, and are held on by permanent clamps to the plastic center tube (the plastic develops hairline cracks from heat and age).

Buy copper tubing (I think I used 5/16") and two small hose clamps. Cut the copper tube to length with about 1.5" inserted into each of the rubber pieces and then sized to fit across the top of the radiator so it lays in the original shape (You can used the original part as a template to size the copper tube before cutting off the clamps). As I remember parts were under $3.00 at Ace Hardware. The copper tube should outlast the rest of the car.

mag5qc

2004/545i/119,000km. Lately, during a drastic week long cold snap I'm getting a low coolant message during cold start-up. It doesn't seem to be urgent as it is happens in the morning only. After reading posts, now is the good time for me to evaluate the coolant tube and connections before trouble sets in.

Thanks everybody for the discussion.

E60I

I spent less than $14 on the copper tube and clamps at Pepboys' and did it this evening. The new tube looks awesome! :-)

While cleaning the reservoir tank, I broke the coolant meauring stick and couldn't retrieve it. In additions to other parts, I ordered the coolant reservoir, belt tensioner, pulley, bolt and belt tonight. At 82,000 miles, it looks like my car is falling apart. :-(

Thanks, BimmerFan52 for the ingenious idea!





QUOTE=BimmerFan52;1526798]I repaired mine as I had the car apart while doing the water pump and thermostat and didn't want to wait for BMW to open to buy the part so I could close the engine back up.

On both ends of the center tube are flexible rubber tubes that connect to the radiator and coolant expansion tank, and are held on by permanent clamps to the plastic center tube (the plastic develops hairline cracks from heat and age).

Buy copper tubing (I think I used 5/16") and two small hose clamps. Cut the copper tube to length with about 1.5" inserted into each of the rubber pieces and then sized to fit across the top of the radiator so it lays in the original shape (You can used the original part as a template to size the copper tube before cutting off the clamps). As I remember parts were under $3.00 at Ace Hardware. The copper tube should outlast the rest of the car.[/QUOTE]

EddieboyS

Thanks for all the info guys. Question though, shouldn't the pressure check my Indie shop did have provided an indication of the leak?