Antifreeze leak in a 1999 plymouth voyager. Lookslike its coming from around oil pan. Water pump replaced last year.Also no heat

..wwwoooaaa.... sounds like you have either: a cracked head, a cracked block, a leaking head gasket, leaking intake gasket,..your antifreeze should NOT mix with anything...

.UNLESS YOU POURED THE ANTIFREEZE INTO THE OIL FILL NECK!!!

Let's give this a shot... first is the question because the oil pressure light stays on when running? The first video tells how to accurately diagnose the pressure switch for fault (most common with Voyagers).
Auto Repair Maintenance How to Check if an Oil Pump Is Bad

The second is how to remove the oil pan to get to the oil pump if it is bad... this guy is just changing the gasket but the work is the same for your Voyager...
Replace oil pan gasket on 01 Dodge Caravan

And last, if it turns out to be just the sender as is most of the cases this next video shows how to change the sender unit on a Caravan which is a Voyager in sheep's clothing...
dodge caravan oil sending unit replacment

on most cars
get it clean, drive around the block
then look, the gasket that leaks is the cause. replace it.
gasket ,o-ring or seal.

or use the UV dye and lamp tool, for $15 and find it more easy.
2 way there are. only.
clean and look, and dye and look.
besides total rebuild.

3.3 AND3.8 ENGINES TAKE OFF SERPENTINE BELT 15MM ON BELT TENSIONER . REMOVE 2 HOSES OFF PUMP. 5 ?BOLTS AROUND WATER PUMP. IT WILL COME OFF WITH ANTIFREEZE LEAKING OUT. HAVE DRAIN PAN UNDER . ALSO IT IS GOOD TIME TO CHANGE THE LOWER HOSES. REINSTALL WITH NEW GASKET, FILL SYSTEM, PUT HEAT ON HOT AND RUN UNTIL THERMOSTATE OPENS, AND CHECK FOR LEAKS, TORQUE IF NESSESARY ( ENGINE OFF)!!REFILL AT SIDE TANK

Check the oil pan and see if it doesn't go there if it does then maybe your head gasket is bad. and if you are leaking just while you driving then it could be a Freeze block plug or bad water pump. Good luck

The oil pump removal procedure for Plymouth Voyager 2000.
A oil pump is usually located in the oil pan. If you want to change the oil pump and replace it with a new one, roll up your sleeves and get ready for some dirty work.
The procedure to remove oil pump is as follows:--

• Drive your vehicle up onto ramps or lifts so you have room to work as you pull out the oil pump. You could also use a jack, but make sure you brace the front wheels so they don't roll. In addition, set the emergency break firmly into position so the car doesn't roll.
• Remove the engine front cover then drain the engine oil and take out the oil pan. It is under the engine and looks like the bottom of the motor.
• Unscrew the oil pump mounting bolts with a wrench and proceed to remove the oil pump itself by pulling it down and out of the engine. Avoid getting any contaminants into the oil pump assembly while removing.

The Water pump removal procedure for Plymouth Voyager 2000.
The water pump is the heart of the Plymouth Voyager's cooling system, circulating the coolant. When the water pump is faulty, it can cause serious damage to the engine of your Plymouth Voyager.

• Disconnect the negative battery cable.Place a drain pan underneath the radiator. When the engine is cool, drain the cooling system from the radiator into the pan.
• Remove the right inner splash shield and the accessory drive belts. Support the engine underneath and remove the right motor mount with the bracket.
• Take off the front cover and remove the timing belt along with the timing belt idler pulley. Also remove the camshaft sprockets, the rear cover to the timing belt and the alternator with its bracket.
• Loosen and remove the bolts to the water pump and remove it from the engine.Install the new water pump after inserting a new o-ring gasket. Tighten the bolts to 105-inch lbs. Make sure that the pump can move freely by rotating it by hand.
• Replace all components in reverse order. Tighten the camshaft sprocket bolts to 75 foot pounds and the timing belt idler pulley to 45 foot pounds.
• Refill the cooling system with coolant and reconnect the negative battery cable. Start the engine and check for leaks when it reaches normal operating temperatures.

Loud noises coming from the cooling system could be a sign that your water pump needs replacing. A leak in the coolant may also be an indicator. You can expect that a water pump will need to be changed every 70 to 100 thousand miles or so in a Plymouth Voyager vehicle.
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What's probably happening is the weep hole on the water pump is leaking water. The weep hole is a warning sign that the water pump needs replaced. You don't have any heat because the impeller in the water pump is no longer circulating water.

go to http://www.autozone.com/autozone/homePage.jsp and sign up, put in your vehicles info and click on repair guides, they have oil pan remove and replace but no guide for the oil pump but its located in the oil pan and usually held on with 2 bolts and a gasket inside the pan, Tough job probably need someone with mechanical experience to help with this.

check your oil for antifreeze in the block if there is any there more than its a gasket

were at on the passenger side? If its in the front floorboard,passengers side.the heater core may be leaking antifreeze.Also the a/c drain it also located in the same area.check your antifreeze,if not low,drive for a few miles with a/c on,stop on dry level place.there should be water dripping under passengers front.that is were the a/c drain is supposed to be.