1999 Pontiac Montana

Smells problem
1999 Pontiac Montana 6 cyl Wheel Drive Type unknown Automatic 129000 miles

We have been having some major problems with coolant, first the water pump went out a month ago so we replaced it, we are now leaking antifreeze everywhere again this time its coming from the back side of the motor, we followed the hoses and this doesn't seem to be it either, and the headgasket would cause the oil to be white or milky color which its not, do you have any suggestions on what it could be? Thank you so much, for your time

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