Check coolant level (sporadic)
 

Hey guys,

My X has 200,000Km's (125,000 Miles) on the clock and for the past month I've had to fill up the coolant level regularly.

I check the level daily but the strange thing is that the level doesn't move and then one day it'll just be empty (with the odd occasion I'll notice a huge pool of coolant on the floor).

Because there is the odd leak onto the floor I'm assuming it is something outside the engine like a hose or the expansion tank.

It only happens every once and a while though which has me a little confused or I'm leaving a pool of coolant at the mall without noticing it...

Anyway I've done a search of the forums and it seems that there are two issues, the coolant tank and the pipe running under the intake manifold, I'd rather go the expansion tank first. Do you think that's what it is?

----- I should add that where I live it never gets anywhere near freezing - minimum 10 celsius or 50 fahrenheit -----

Wild Guess

-> https://www.agacoolantpipe.com/product/n62-coolant-pipe
-> BMP Design: BMW V8 Coolant Leak on N62 Engine - YouTube

Mate, if it's leaking there will be trace evidence at the source. Shouldn't be rocket science to locate it before you start buying parts randomly.

Ants - You would think so... but no dice so far - It's like a valve opens - drops its guts and then closes again, as I said it goes for weeks without losing a single drop then all of a sudden loses a shiteload

sounds odd to me mate. in all my years on the spanners, i've never experienced a fluid leak that leaves no trace of its source.

Check the lower radiator hose temp. sensor.
The O-Ring is potentially suspect........it will hold when the coolant is warm and drain when cold.

Charlie

So the latest - I drove over to my parents tonight and got the warning about 5 mins before I got there, when I arrived there was a fast drop of green coming from around the front left suspension - out from the "stiffening plate" and the reservoir was bone dry.

I looked around to see if any coolant pipes looked soaked but everything looked dry (from the top with a torch).

If I had a leaking valley pan pipe it would be shooting into the cylinders wouldn't it and therefore not draining out the bottom so I'm assuming I can disregard that possibility (Is my logic correct?) so my only other guess is that I have a busted fitting somewhere outside and possibly at the back of the engine...

I haven't cracked out the Bentley manual yet but will have a look tomorrow

Thoughts/opinions

My opinion is, you need to get under the vehicle and have a good look. You saw coolant draining out near the left suspension, so trace it back from there. You have a good lead, but if you don't follow it, how can anyone help you?

Thanks Antz, I was hoping that someone who has had this problem before would chime in and mention whether they had coolant in the intake... that's basically what I was after. I do appreciate your help but I was trying to garner some information prior to having to find a level surface and unbolt the stiffening plate to try and find the coolant leak itself.

Feel around the bottom of the expansion tank.
My seam was leaking and it took a while to find it.