One tire valve stem looks like it popped out a little on my 08 Rabbit, and is leaking badly. Cam I screw it in with a standard valve stem wrench, or does it need to go t the dealer?

the best way to find out the leak is to immerge tire in water you will see the leak. don't forget to check the valve without cap

There is a hex screw on the lock ring you need to loosen with a Allen wrench

I can tell you some things about this and what you decide to do about it is up to you.

Here is what can happen. The valve depends on the valve spring to close the valve. If there is a leaking oil stem seal, the oil can try to run into the cylinder. As it does this, the valve starts sticking as the valve stem gunks up. The valve spring can also be weak or broken and fail to close the valve.

You can change the valve spring and the oil seal on the stem on some motors by placing the cam where the valve is closed. Then using an adapter, force air into the problem cylinder(at the sparkplug hole) and the air pressure will keep the valve from falling into the engine. You then use a valve spring compressor and swap the springs and replace the stem seal.

On some motors, the cam is on top and in the way. Other motors use the overhead cam to press a rocker arm with the valve offset and accessible. The pushrod was eliminated and even lifters were eliminated. You can get loaner tools at Autozone, Advance, or Oreilys.

Another option is to have your head sent out and rebuilt or go to Car-parts.com for Salvaged heads with shipment to your door and all the contact info you need to get the part.

If you remove the head you will need new head bolts as the old ones stretch. Of course a Torque wrench is highly recommended as the 4 cylinder heads were subject to bad head gaskets.

You should take out the number 1 plug and look at how it is burning. You may have a water leak causing the valve to fail. The clicking noise can be the valve failing to return to its base. Hydraulic lifters can collapse too. But your noise is the extra space in the valve train causd by a sticking valve, bad lifter, or broken spring.

There are some Paperback books with pictures to do this job. You can see if you fell comfortable about trying to fix it yourself.

Hi, if you are referring to the tire pressure sensors they are actually the valve stems that you put air into the tire with, the sensor is inside the tire and it is not able to be taken out without taking the tire off of the rim and removing the sensor and installing a standard valve stem. But if you remove the sensor your little tire warning light will stay on. Good luck

air contracts in colder air temps and is normal that tires could be a little lower but should be fine when you start driving as the air heats up..if its just one tire check for a leak or something in the tire(small screw, nail) that would cause air to leak out in the cold temps. if all tires are doing that check valve stems and tighten them with valve stem tool available at any auto parts store. If tires were replaced they might not have replaced the valve stems and that could be it too.

yes as well as the rim

mix some water and liquid dish soap
spray onto the valve stem and around the rim where it meets to tire and watch for bubbles

Replace the valve stem or have it replaced. There is a special tool to unscrew the valve stem. Remove the wheel and tire from the car and depress the pin in the stem to release the air in the tire. When you have about 90% of the air out of the tire, insert the tool into the stem an turn counterclockwise to remove. After you install the new valve stem, get a ride to a gas station that offers free air and fill the tire up. As long as the tire is still seated to the lip of the rim (check just for your safety but I very highly doubt it unseated from the rim) and fill the tire to the cold psi rating which is stamped on the sidewall of the tire. If you want to check the tire itself for a slow leak prior to doing the steps above, here is what to do. Get a pan or plastic tub that is sightly wider and longer than the tire and rim. Fill the tub with water and set them it in the water (while it is still filled with air) and slowly roll the tire in place and look for small air bubbles to rise. If you see bubbles, there is a leak.

if its 1 tire low obviously look for a nail in the tread or a leaky valve stem. if you cannot find a nail/screws etc in the tread. take stem cap off spray windex on stem right into the center, if you see bubbles, your stem is leaking, replace the core, cheap... available at auto stores, also need special tool to remove stem( cheap).
if all 4 are low, might be due to cold temps, tires loose i think 3 psi per 10 deg drop in temp,

Could be a couple things, I'd look at either a bad valve stem or to see if the bead is leaking. Take a spray bottle with some soapy water in it and spray it on the valve stem and all along the inside and outside beads. If you see bubbling anywhere that's where the air is leaking out. Any chance you may have run over a nail or something on the way home?

not just chrysler, there are many wheels from manufactures that have the same type of problems. chances are they will not help you.