My 940 LPT does the same thing.
A few days ago I replaced the rear backbox(£34) as rusted through/ advisory on MOT. Fitted new BM box and fired up to cure exhaust paste and water was dripping out of join until hot enough to set. Then spitting out of tailpipe! Always done it when weather cold and no coolant loss.
The new Klarius tailpipe is so badly bent/ formed I didn't fit it as so restrictive. Re-fitted old one. Will be going back to ECP.
The exhaust is Euroflow and lasted 5 years. The over axle pipe will need doing next, about a year but midbox to cat still looks OK. Downpipe and BM cat good. May try a Volvo system next time, although didn't last 3-4 years on my 240. Parked on grass and not used much. At least should be bent/formed well.
James.
