I'm trying to perform a coolant change on my 08 535xiT, but am running into some issues. First, how on earth do you get at the radiator drain plug?


This picture was taken from above, but only because I couldn't get at it at all from underneath with the splash shields removed.

Also, is there a engine block drain on the N54? Where?

I'm trying to replace the expansion tank as well, but can't get the lower coolant hose off. I unclipped the connector, but the hose seems fused to the tank. Any tips on getting it off?



Thanks!

 

From underneath, the drain plug is accessible just above the lower radiator hose on the passenger side. Save yourself the hassle and get a replacement plug as it will likely leak after being opened. You'll also want to get a bit of tubing to guide the coolant to your bucket. If not, it'll run our from all over the place. Better yet, remove the lower hose to drain the coolant.

Don't worry about the expansion tank. They're MUCH more reliable than the E39's.

Draining the block is overkill, but then again so is changing any of the coolant before 100k. You can check the status of the coolant using a volt meter. It does last a loooooong time.

 

I'd just remove the lower radiator hose. Once you have pulled out the metal clip then uses a screwdriver or plastic pry bar and twist the fitting loose. Just don't pry too hard or you'll be buying a new hose.

 

Probably don't have a radiator plug.
Newer E60 don't have it anymore. Just disconnect lower rad. Hose instead.

 

I also just pulled the lower radiator hose off where it connect to the radiator too. First, loosen and pull back the clamp. Mine then actually pulled off pretty easily. Make sure you have something to catch the radiator fluid too.


I then ran the garden hose through the radiator to flush it out. After that, I hooked up my shop vac to the lower radiator hose and got out a little more fluid. I then buttoned it all up added distilled water and approved radiator fluid and did the bleed procedure (with a battery charger going) twice. It was an easy job.

 

Well, my 2010 E60 has a drain plug, but I do agree that disconnecting the hose is easier than using the drain plug, especially since the drain plug is prone to breaking.

 

My 2010 does not have a drain in the radiator. Mine is the 535 and after removing the inter cooler I was completely baffled. The only way I could drain it was to remove the radiator hose.

 

Hummm. My 2010 535i does (well hidden red plug on the driver's side of the radiator) but it drained so slow I ended up just pulling off a hose. The part number is 17112247346.