My 93 mpv, 4 wheel drive, has a bad water leak behind engine. It stops or slows down sometimes but is worse if I have the air on, weird. Don't think it could be a freeze out plug or it would never slow down. All hoses except heater core hoses have been changed. Would the rear or front heater core hoses cause a leak behind the engine? And does anyone have a repair manual?

I'm not sure about the 93mpv but I have a 90 mpv with a water leak behind the engine also. It turns out one of the water hose from the left side of the engine block(underneath the air intake block) to the water temp. sensor(I think it calls water temp. sensor)rusted out and causes the water to leak. Hope this helps and good luck to you.