Water leaking fron back of engin

I couldn't find a heater hose diagram specific to the 1999 Chevrolet Venture with rear heat and air, but I can give you the general location of the heater hoses and how to identify which ones go to the rear heat. The heater hoses on a 1999 Chevy Venture are located on the passenger side of the engine compartment. There are two heater hoses, one that is hot and one that is cold. The hot heater hose will be connected to the heater core, which is located under the dashboard. The cold heater hose will be connected to the engine. To identify which heater hose goes to the rear heat, you can look for the hose that is connected to the heater core outlet that is labeled "Rear Heat." The other heater hose will be connected to the heater core outlet that is labeled "Heating Core Inlet." Once you have identified the heater hoses that go to the rear heat, you can reconnect them to the heater core. Be sure to use new clamps when you reconnect the hoses. Here are the steps on how to replace the heater hoses on a 1999 Chevy Venture with rear heat and air: Disconnect the negative battery cable. Drain the coolant from the radiator. Remove the heater hoses from the engine and heater core. Install the new heater hoses. Fill the cooling system with coolant. Reconnect the battery cable. Start the engine and check for leaks.

Sounds like a blocked heater core. Could be different reasons. You get any check engine lights? If not, you may want to back flush the heater core by using a garden hose and adapter you can get at an auto supply store. You would hook up a running garden hose to the side that is cold and hopefully the prtessure would unblock any sediment or blockage.

Hi there.
Well you can either have a problem with either radiator outer {dust/dirt in outer core of radiator or clogged up inside were water goes, or soft hoses,blowen head gasket plus a few others ,but first go to garage to were you blow up your tyres and use the air hose and blow out the radiator core where the air goes in, 2 drain out radiator water and then refill with water at 1 ltr at a time and then check your info car book and find how much water the radiator takes ,if it dosent take all the ltrs then the radiator is blocked inside.
if engine runs rough missing etc then get your Head gasket checked out.
When you say no heat is that with heat on gauge or no heat from heater, as it could be heater blockage same as radiator core. So let me know how you get on.

It sure sounds like the heater core, especially if you have water leaking inside the cabin. The two heater hoses only go from the engine to the firewall, and do not go into or through the firewall. They connect to the heater core right at the firewall.
Check carefully around the back side of the engine and the heater hoses, though. If a freeze plug is leaking, water will be dripping off the bottom of the engine. If it is leaking before the firewall, that would not be the heater core.

Your heater core has developed a leak - the wetness on the passenger side carpet is engine coolant
from a heater core leak, or a leak in one of the two hoses connected to the back of the heater core.
Your strategy: disassemble dash down to heater core, determine whether you'll need a new heater
core or new hose (or new hose clamp), then replace the offending part.

Could be the heater core, or where your heater hoses connect at the firewall. Heater core leak would more than likely put steam in the vents of you car when heater is on and hot and fan on. If the leak is just in the engine compartment, it`s a hose or a loose connection.

U can flush out the heater core by removing the heater hoses at the engine side and flushing clean water through both hoses.stop leak is junk,i would not advise using it,your right all it does is block the heater core.

yeah hose and clamps are the cheap easy way to go there, or if your lucky, the leak is right at the spot where the hose meets the metal and you can just cut the end off and put it back with the old clamp

the valve that allows the hot water into the heater core is not opening. most likely electronic issue. also check all vacuum and electric lines.

it is the heater water supply and return, that supply water to the heater core to supply heat using hot water from the engine, the hose clamp my be loose or the hose has a hole in it you have to trace it from unner the hood fire wall to where it connects to the heater under the dash