Draining coolant on E70 3.0
 

I feel silly asking this question, but I've spent 30+ min searching the forum and everywhere else I can think of, and I can't seem to find an answer on the proper procedure for draining the coolant out of an '08 3.0.

I want to do as thorough a drain and flush as possible, so I'd like to do the block too. Don't believe my radiator has the plastic screw the one other post I could find mentioned.

Please help the simpleton out.

Never looked on an E70 but typically on the inline 6's the drain bolt is between the first and second cylinders on the passenger side and only visible from below.

MPE50, it should be there driver side, kind of hard to see/feel. It is flush (no pun) mounted with a large "plus tip" slot for a screw driver. I was in the neighborhood just this weekend (07 3.0) For what it is worth, to get as much of the fluid out, I drained the system, refilled with straight di-water, and then ran the bubble removal sequence (x2). Hope this helps.

Ooops I was just talking about the radiator drain.

Thanks for the replies. Definitely didn't see anything on the bottom of the radiator. I had to replace the radiator at 45,000 miles, so it's the newer style.

And I'll look for the drain plug by the number two cylinder. I assume it probably looks like just any other bolt, or is there something to distinguish it as coolant?

You may need to just disconnect the radiator hose then if you cant see the drain hole or it doesnt exist. I read that it was on the driver side corner, i havent done mine yet.

I really don't think there is one. From what I've been reading, there isn't an engine drain plug on the n52 either for these years. Just recommendations to drain from the radiator hose, and the hose on the water pump to drain the engine. Not sure what was wrong with a drain plug...just like I'm not sure what was wrong with a dipstick. lol I guess it's mostly an attempt to force owners to go in for service.

Try this video: https://www.youtube.com/watch?v=-J6rf5NwrAQ

I had my coolant changed last week at the dealership for $160. Figured it was worth the money since I didn't see much out there for the N55 engine.

Dealerships don't drain the block when they do a coolant flush as it's not part of the documented procedure. Also probably why it's recommended every 2 years as you're really only replacing about 1/2 the coolant.

A drain (first) and fill (refill) is not essential to a complete flush, but it is more efficient.

If half of the contaminating solute remains after each partial drain and diluting refill, then ½^n, when n=5 is almost 100% gone.

If you burst your guts and crap into your belly, the doctor will do this serial dilution about ten times estimating that 1% of the bugs remain after each dilution. A homeopath uses the same procedure when he gives you tincture of cyanide.

https://en.wikipedia.org/wiki/Dilution_%28equation%29