Could be any number of reasons. First if the check engine light is on, make sure you read the codes which will give you clues as to what is wrong. It could be a misfiring cylinder, bad/dead spark plug, warped cylinder, damaged or missing motor mount, or even a damaged/worn timing chain. A simple cause would be bad fuel or water in fuel, or a clogged air filter. Check your oil level, spark plugs, and air filter first, these are easy and inexpensive to replace.
http://www.carspace.com/guides/Toyota-Echo-How-to-change-oil
You have to take out the engine to get to it.
5kg
The Toyota Echo has an inline 4 cylinder engine. The number one cylinder on all inline 4 cylinder engines is the first piston at the front of the engine. The front of the engine is the end that is opposite the transmission.
Yes.
How to open hood on Toyota echo
Follow the positive battery cable down to the engine. It is bolted to the starter.
On top of the engine, but you have to remove the cover to see them.
yes
If you are asking if you can tow with a Toyota echo, the answer is yes. See related link for a video of a Toyota Echo towing a small trailer (and off roading).
no oil
No, it can't do that. Maximum you can get is trouble codes...