M62 coolant crossover pipe cracked into 4 pieces after cold start

[eirikr]

First time posting here.

99K miles, everything works and (seems) normal and engine was running smooth. Been away for two months and parked in the garage with battery tender. Returned home and started the engine, idle for about 10 min and temp guage not moving at all. Shut down the engine and found coolant leaking from the back of the engine. Outside temp was freezing, about 26-28F, but I think inside the garage it's just above freezing.

Crawled under the car and found a crack on the crossover pipe, when I got to the pipe I found that it actually cracked into 4 pieces.



I replaced the crossover pipe and bleeded and refilled the coolant. Started the engine and ran it for a few minutes to around 115F, then coolant started leaking from the LH ignition coil cover. I removed the cover and found the ignition coils filled with coolant. In the photo I already soaked up some coolant, it was filled to the edge.



After I removed the valve cover and soaked up all the coolant, I found where the coolant is leaking from:





I've searched many forums and found nothing similiar to this failure. The pipe cracked into 4 pieces seems very unusual.

Any idea or suggestion? I am thinking it is a cracked head or block.

Thanks