FIXED and RUNNING!!! Sudden loss of Coolant, steam coming from engine bay!

[bcredliner]

To test for a leak tap water is fine. You will be draining some of the system to fix the leak and you can easily drain the rest. It sounds like it was a catastrophic failure of a cooling system component rather than a big leak. Pressure testing is the best way to check the system but I don't think you will need to do so in this case. I would fill it up and see if it runs out anywhere on its own. If not, I would start it up and verify the source. Circumstances as you describe are most often a ruptured hose. Often the rupture is at a hose clamp. That's my guess to add to the others.

[David.X5]

If you think its the crossover pipes or pipe seals, I would replace the metal crossover pipes, too. The ends were pitted on mine, and I tried to polish that out, but it ended up with a slow steady leak there. Its never fun to do the job the second time... The metal pipes are not that pricey on the M62 and not that hard to remove. Spend some serious time cleaning the grooves where the end seals sit for those pipes. Mine were filled with corrosion and grit.

Anyway, the cross over pipe would not be high on my list as a source of a gusher either. The seal sits between two metal parts - even if the seal is toast, you wouldn't get a flood coming out. A burst hose or cracked plastic hose end would open up a big hole that could loose a lot of fluid in short order.

[wfwright2]

The other big leaker is the valley pan gasket/plate. BMW has provided an updated pan with gasket. Requires removal of intake manifold, coolant pipes, etc. It makes sense to renew the oil separator and crankcase ventilation fitting on intake manifold while you have dug in tat far.
I found the rear coolant manifold a pain to get re-installed.

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[pwvarley]

Originally Posted by wfwright2

The other big leaker is the valley pan gasket/plate. BMW has provided an updated pan with gasket. Requires removal of intake manifold, coolant pipes, etc. It makes sense to renew the oil separator and crankcase ventilation fitting on intake manifold while you have dug in tat far.
I found the rear coolant manifold a pain to get re-installed.

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I am adding a bunch of part numbers to a list so when I get under the car this weekend I already have everything written down.

I can't find anything on crankcase ventilation fitting for the intake manifold

If you could point it out that would be great

RealOEM.com - Online BMW Parts Catalog

[David.X5]

That cross over pipe is a heavy casting. Can't imagine it leaking. It has gaskets on each end (the two heads) and then the orings for the metal tubes in the middle.

The heater hoses run behind the block. Probably worth taking the engine acoustic cover off and looking around with a mirror to localize the source better.

[pwvarley]

Originally Posted by David.X5

That cross over pipe is a heavy casting. Can't imagine it leaking. It has gaskets on each end (the two heads) and then the orings for the metal tubes in the middle.

The heater hoses run behind the block. Probably worth taking the engine acoustic cover off and looking around with a mirror to localize the source better.

The accumulator is heavy casting or the pipes that go from one end to the other are? I thought someone mentioned it being a good idea to replace those along with the O Rings

[pwvarley]

After looking into everything I am tempted to order the Valley Pan service kit from ECS which includes the new valley pan and associated gaskets, the two gaskets for the for the water accumulator and then the o-rings for the coolant pipes as well as a few other gaskets I believe.

They have a BMW one listed which includes the BMW valley pan or one assemblies by ECS with an upgraded valley pan. I was pretty sure the Valley pan was bad so would the upgraded one be the better option?

Also while I am doing that anything else besides the oil separator that I should switch out while I am there and ordering parts? No other mechanical issues with the car as of now, so this would be preventative

[David.X5]

Valley pan is different. I thought you were asking about the crossover - the metal casting that the metal tubes slide into at the rear of the engine. That cross over is heavy. The metal tubes are pretty lightweight. The valley pan is medium, but corrodes at the gasket sealing surface over time, so the putted gasket surface becomes the limiting factor.

[Helihover]

I wouldn't buy the valley pan kit or what ever your looking at. It's a rip off. Total price for a VP gasket repair should not exceed 15 bucks (this doesn't include the ccv). Buy yourself a tube of black rtv sealant instead of a new VP.

You could replace the ccv diafram, rear coolant hoses, intake gaskets, ect ect.

Been real busy at work lately, but I'm trying to follow this thread. I've done this procedure 2-3 times now and know this area well.

[bcredliner]

I wouldn't be buying parts on a seems to conclusion. The key here is a sudden loss of coolant and I assume with no prior indication of a coolant leak. If the leak showed without starting the engine that indicates a major leak that doesn't even need the system pressurized. I suggest you do what you need to do to confirm the source and start with eliminating all hoses. Have you removed the plastic cover under the engine and jacked it up so you can take a flashlight and look up toward the top to of the engine?