Cant remove oil fill cap on my 1999 dodge grand caravan

There are a few things that can cause this,you will have to remove the wheel and brake drum to inspect it . Seized wheel bearing, grease or oil on brake linings,seized cable,if hydraulic seized wheel cylinder pistons. If the linings have oil or grease on them replace them on both sides for even braking.

There are two possibilities, one is the thermostat. Many people remove them which spoils the whole heating / cooling system. Since you changed the thermostat, I would check the heater valve on the heater which allows the hot water to circulate through the heating system.
It may be necessary to remove the heater box and flush the heater core since you talk about a lot of rust, which could have clogged the heater core and / or the pipes leading to the heater.

The oil filter location on the 2012 Dodge Grand Caravan with a 3.6L engine is on top of the engine. Standing in front of the van, look slightly to your left on top of he engine. just where the air intake goes to the engine. You will see a 2.5 in black cap with a large hex nut make on top. The cap is labeled "Do Not Open With Engine Running'. You filter is inside this cylinder.

The oil cap depending on what motor you have is on top of the valve cover or on top of an extension tube along side the valve cover and it will look like the picture below, might be black in color. these simply unscrew to remove.
Here is a short video and there are more on this page to help you. If this was helpful a vote on the thumbs up would be greatly appreciated for the free advice. Thanks for using Fix Ya

http://www.ehow.com/video_4949202_oil-change-remove-oil-cap.html

This indicates that there is low oil pressure, check the oil pump pressure, could be wearing out.

OPEN GAS CAP FLAP THEN YOU NEED TO DRAIN GAS BELOW FILLER NECK.THEN LOOSEN REMOVE SCREWS IN THE GAS CAP FLAP AREA WHERE FILLER TUBE CONNECTS THEN GO UNDERNEATH VAN LOOSEN REMOVE HOSE CLAMPS AND REMOVE THE HOSE AT THE FILLER NECK BELOW THE GAS TANK.SPRAY WD40 AROUND HOSE AREA AT METAL FILLER TUBE STICK OUT GAS TANK.CAREFULLY USE LARGE PAIR OF CHANNEL LOCK PLIERS TO REMOVE WORK HOSE OFF METAL TUBE FROM GAS TANK. IF YOU CANT REMOVE HOSE WITH HANDS.BECAREFUL NOT TO MAKE ANY SPARKS.PLACE RAGS AROUND ANY METAL PARTS TO KEEP CHANNEL LOCKS FROM HITTING METAL MAKING SPARKS.

This sounds like you may have a hole in your radiator. First pull your radiator cap off while the car is off look in there and see if there is any fluid in there. If not fill with antifreeze. Once you have done this wait a minute and see if it leaks out if so then there is a leak in the radiator. Next if this doesn't provide an answer look at your hoses you could have a leak in one of the hoses from the radiator to the engine.

yes it will swap and you have to remove it from the bottom of the van remove the screw/clips from inside the filler door and then from underneth disconect the filler tube ti tank and the vent hose to the tank i belive there is a bracket also holding the filler tube to the body with one bolt then it snakes out of the va r insalating is just reverse

I have a '98 Grand Voyager 3.3 L V-6, it's located on the passenger side fender at about the middle of the engine compartment, should be clearly labeled. countrycurt0