Been almost 1000 miles after engine replacement. From very beginning I've been noticing some coolant being spewed out around the intercooler expansion tank.
To make it clear. This only happens when going really highrevs / redline and under load. I can drive around all day long and there will be no signs of it. Need to be pushing the engine for this to happen.
This is the part I'm talking about:
http://www.realoem.com/bmw/showparts.do?model=YA81&mospid=55015&btnr=17_0677&hg=17&fg=05&lang=enUS
It's definitely in the epicentre of the problem but I'm not sure if it's coming from the cap or from a crack in the expansion tank (the SA did a pressure test with over 1 bar pressure and there was no signs of coolant anywhere on the tank).
What I observe , is some coolant accumulated in this small "pit" marked red:
And some drops all over the engine. Here's schematically how the distribution of drops that I usually see , there's also quite a large coolant stain on the inside of the hood of course:
(not the actual engine)
So I'm sure it's not coolant overfill, especially since quite a bit of it has been already "flown" out.
Not sure if it's still a crack in the expansion tank - I don't know if ~ 1 bar pressure test is enough and how much pressure is developed during high revved engine operation (turbocharger operation) ???
The "picture" and the distribution of coolant DOES point to a crack in that "pit" spot as the most likely reason.
Or it's just the cap, which I'm also not sure if it's a pressure cap or just a regular cap that is NOT supposed to let any coolant out. The SA said it's a pressure cap but if you look at the part description in the realoem link above it says "02 Cover lid", and if you look at the main expansion tank cap here:
http://www.realoem.com/bmw/showparts.do?model=YA81&mospid=55015&btnr=17_0615&hg=17&fg=30&lang=en
It says "06 Radiator cap 2,0BAR"
which to me looks like it's the pressure cap and the other one isn't. So it could be the cap - although I can't see how the coolant can be distributed that way if it came from "under" the cap ...
p.s. now that I thought about it looking at the pics I made, it actually could - if you imagine the coolant flying out from the cap area initially forwards and at some point being blown off and backwards since a) the car if moving fast and b) radiator fan blowing it backwards, then the drops would indeed be appearing on the engine cover like that.
To make it clear. This only happens when going really highrevs / redline and under load. I can drive around all day long and there will be no signs of it. Need to be pushing the engine for this to happen.
This is the part I'm talking about:
http://www.realoem.com/bmw/showparts.do?model=YA81&mospid=55015&btnr=17_0677&hg=17&fg=05&lang=enUS
It's definitely in the epicentre of the problem but I'm not sure if it's coming from the cap or from a crack in the expansion tank (the SA did a pressure test with over 1 bar pressure and there was no signs of coolant anywhere on the tank).
What I observe , is some coolant accumulated in this small "pit" marked red:
And some drops all over the engine. Here's schematically how the distribution of drops that I usually see , there's also quite a large coolant stain on the inside of the hood of course:
(not the actual engine)
So I'm sure it's not coolant overfill, especially since quite a bit of it has been already "flown" out.
Not sure if it's still a crack in the expansion tank - I don't know if ~ 1 bar pressure test is enough and how much pressure is developed during high revved engine operation (turbocharger operation) ???
The "picture" and the distribution of coolant DOES point to a crack in that "pit" spot as the most likely reason.
Or it's just the cap, which I'm also not sure if it's a pressure cap or just a regular cap that is NOT supposed to let any coolant out. The SA said it's a pressure cap but if you look at the part description in the realoem link above it says "02 Cover lid", and if you look at the main expansion tank cap here:
http://www.realoem.com/bmw/showparts.do?model=YA81&mospid=55015&btnr=17_0615&hg=17&fg=30&lang=en
It says "06 Radiator cap 2,0BAR"
which to me looks like it's the pressure cap and the other one isn't. So it could be the cap - although I can't see how the coolant can be distributed that way if it came from "under" the cap ...
p.s. now that I thought about it looking at the pics I made, it actually could - if you imagine the coolant flying out from the cap area initially forwards and at some point being blown off and backwards since a) the car if moving fast and b) radiator fan blowing it backwards, then the drops would indeed be appearing on the engine cover like that.