I'm changing the antifreeze for winter and wanted to flush the system. The procedure calls for draining the radiator which I have figured out but it also says to vent the engine by loosening the air bleed vent screw located on the thermostat housing. Is this the housing the thermostat goes in for opening and closing the flow of antifreeze to the engine? If it is the only thing I see in sight is a screw in the housing with a hose attached to it. Would this be what they mean?

I thought since everything drained through the drain hose at the bottom of the radiator on the left through the drain hose that if I took out the thing I saw it would drain there?

I'm thinking the vent just lets air in and the antifreeze in the engine drains out through the radiator?

I'm thinking if this was loosened or the hose removed its going to drain from there or will it continue to drain out the radiator?

Thought I'd ask before I started!

This way if that is the screw vent I see I'll know where to put the pan?

Be sure to read this link, before beginning:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post235973

What car do you have? Year, Make, Model, Engine

I don't know what type of car you have but some do vent through the t'stat housing. The "screw" you see with hose is most likely a bleed valve, like on brake cylinders. It should unscrew to the right. Open it slightly as you fill the radiator and you should hear air coming out. When it is full, anti freeze mix should come out. Shut the valve, let the car warm up and reach normal temp and CAREFULLY crack the bleed screw again to make sure all of the air is out. I know some Honda's work this way.

1997 Plymouth Grand voyager SE 3.3

It said in the instructions to bleed so the antifreeze in the engine would drain also. I'm thinking I bleed it and the antifreeze in the engine will drain out through the radiator drain hose and maybe a few drips when I remove the vent screw?

Use the traditional green antifreeze:

http://www.valvoline.com/pdf/Zerex_CoolantChart.pdf

It's good practice to remove the bottom radiator hose at the radiator, in order to drain all sediment from the radiator. Just opening the drain is not enough.

Thanks.

You shouldn't have to remove the screw, it is hollow and vents when loosened. Let some of the fluid run out and close it back up. 3.3 is that the mitsubishi engine? I had a 3.8 great engine. Good luck

Put the antifreeze in then tap the starter with the radiator cap off. Then replace the cap run for a few minutes and remove the cap once more and top off if necessary