Hi,

my name is Dirk and I'm from Germany.
1.)My Van loosing water on the engine (staying for the hood left side). Finding water on the ground.

2.) Test drive another Venture, running fine but in the overdrive there was a jerk. Just one time on the test-drive about 55 mph goes to 65 mph.

 

Hi !(Hallo!)Likely leak is at the very back of the engine near the firewall . The heater hoses do connect to the firewall at the back of the engine,if one is torn,cracked or has come loose then it can cause this leak. It is difficult to see the back of the engine by the firewall from under the hood but you might be able to see the leak from under the vehicle looking at the firewall area and the back of the engine. A coolant pressure test will usually help locate the leak.Most shops and dealers have this pressure tester and this tester can be purchased at a parts or tool store as well. But it is possible that one of the heater core hoses are leaking at the back of the engine and is causing this here. The pressure tester should help you isolate the source of the leak.Make sure you pump it up to about 15 psi and then check for the leak.
Perhaps - leakage of these hoses (see the picture)

 

Alright, many thanks for sending the picture. I try it with the pressure.
The leak is on the side below waterpump. Waterpump loosing no water.

Do you know the mistake with the jerk in the overdrive?