Rattling metallic noise engine on start up ON 2013 CHRYSLER 200 LX

Have the exhaust system checked, that would be the most common source of a rattle.

battery in keyfob may need replaced

The oil light means that you have low oil pressure. The rattling noise confirms the diagnosis. There are a few things to check immediately. First check the oil level. If it is low, fill to normal level and retest. If it is normal, verify that you have had the oil changed when due. Clogged oil filters can cause the symptoms. If neither of these is the case, you may have to have the oil pump serviced. The problem could also be with the oil pickup assembly in the oil pan sump. These need to checked out by a mechanic.

1. Engine Noise. With a bad oil pump sufficient engine oil will not get to all parts of the engine, especially the top end, and you will get engine noise with metal parts that would normally be lubricated and quiet knocking due to metal to metal contact. Engines with hydraulic lifters that become noisy can be a sign that they have insufficient oil supply. In addition to the hydraulic lifters, your valve train may begin to make noise if your oil pump begins to fail. Valve train components need to be properly lubricated as well. A bad oil pump can result in a lot of additional noise from your valve train system.

2. Higher engine temperature. Poor lubrication because of poor oil flow generated from the pump will cause friction in the engine and the engine temperature will rise. Good oil flow is essential for lubrication and reducing friction to a minimum.

3. Low oil pressure. The oil pump generates oil flow through the engine but tolerances between metal parts produce the oil pressure. Very worn engine bearings will result in low oil pressure. Thus a worn engine will have low oil pressure even though the oil pump may be fine and there is no issue with the oil pressure relief valve either. However you will also experience low oil pressure due to a failing oil pump because poor oil flow will also result in lower oil pressure.

If your oil pressure warning light has been triggered in your engine, the causes of the low pressure need to be properly investigated because the problem may not be with the oil pump. People replace oil pumps assuming that is always the problem and then still have low oil pressure because the pump was not the problem to begin with.

Oooooooo... I think that engine is GONE, Miguel... not even rebuildable, I think it's ruined.

The drain plug or oil filter may have been loose, allowing the oil to drip out, but since you didn't find any oil on the ground, that's doubtful. What's MORE likely is that you threw a rod (the rattling noise), and that rod broke a hole in the side of the crankcase and blew all your oil out the hole. If I'm right, that engine can't be salvaged... none of its internal parts are good for anything but scrap metal now.

"Rattling" is normally due to one of two things:

1. On heavy acceleration, rattling is usually due to low octane fuel.
2. If at all times, it can be due to low oil pressure.
   
   Rattling can also occur if the engine timing is way out specs. This will normally be accompanied by a substantial loss of power on acceleration.

not the water pump as the noise will remain constant hot or cold
you leave very important details like make . model , year and engine type petrol or diesel so answering becomes a hit and miss affair
if the engine has a timing chain it indicates that the hydraulic adjuster is loose until oil pressure is built up which equates to a badly worn chain
next if an incorrect oil filter was used , the oil will drain back over night and , chains, rockers, hydraulic lifters will all rattle until pressure is built up
incorrect oil viscosity will drain down quickly and will take time to build up pressure as well
you may have to find an accredited service shop and leave it there over night so that the diagnosis can be made in the same conditions for them as for you and then get a quote

Have you checked your oil? Sounds like you may have run it way low, the loud metallic noise is probably metal on metal contact inside your engine, add oil and it that fixes it, count yourself lucky, if not need to take it to a shop.

check oil pressure possible valve tapping -start vehicle and open hood if the noise is on top and sounds like metal tapping u may have a problem with a bad lifter ,oil pressure not lubing head,bent valve/push rod,loose rocker arm. if noise towards front check belts and pulleys-power steering level

This may be due to old oil. I'd first try changing the oil. The viscosity of old oil may be to thin causing serious run off in the top end. All of the lubrication may be off of the valve assembly causing it to chatter and make these noises until the motor can re-lubricate the valve train.

Also, it may be due to low oil, to heavy of a wieght of oil (such as 15w40 or 20x50). I believe with most of the 04's the recommended oil weight is 5w30.

Try an oil change and see if the noise goes away. If it doesn't I'd do a quick visual inspection under the hood for rattling parts while the engine is running. It could just be a loose housing or something causing the noise. Hope this helps bud!