Car Forum World

2003 Chevy venture, leaking antifreeze badly from someplace on behind of engine?? C?
Just had thermostat replaced and now have awful leak but only when car is running, can this be the dreaded intake gasket on this car. never been changed

The dreaded thing on the GM 60degree V6 Motors like your 3400 is the Intake Manifold Gaskets not the Headgasket. Im going to go ahead and say its either the lower intake manifold gasket or the other possiblility if it comes out and seems a pool on the ground is to check your heater core.

Check for heater hose clamp being loose or crack in the hose creating the leak.

Could be any no. of things. There are some garages that do a free check and estimate of what is wrong. Go to one of these and have them tell you what is wrong.

If it's showing on the passenger side, at the passenger cabin, then, I am sorry, but it's probably the dreaded head gasket, as they all seem to leak at the rear head on the passenger side. Have it properly identified to make sure.

THIS may sound silly but, go to your local auto parts store ask to rent a coolant pressure tester, go back to the place of car, jack up the front end, fill radiator with water and install tester on radiator, attempt to preserve pressure of about 10psi, now get under car with a light and attempt to watch the place of the leak. you may want to be able to find it without any trouble, if you can not then remove rhe accessories that are blocking your view....This may take a little while but you'll get a professional job done cheap..good luck