yes
No, it won't. Synthetic oil typically exceeds Toyota's recommendations for oil, so this will have no impact whatsoever on your warranty.
yes you can synthetic oil can go in any engine
No problem at all.Tip: Always use Fully Synthetic engine oil in your car/motorcycle.
In a Brand new engine it is recommended that you get the rings seated before you start using Synthetic oils. So run your engine for 3,000 miles and then you can switch to a Synthetic.
only possable if you have the same engine e.g 3s-fe to a 3s-fe but use the old manifolds and mounts for which the motor is going into ive done heaps of these but you cant change a 3s-fe in a 4s-fe then the mounts are slightly different but not hard to make new ones.
Engine or motor...???
After the break in period it is not an issue.
conventional. I wouldn't put synethic in it unless it has already had it in the engine. Synthetic is mostly used in high performance or new vehicles. Synthetic won't do anything for an older engine
Synthetic engine oil is considered better because it does not break down as fast. thus, if u use it as normal (tho its twice the cost) u almost have no probability of having too much friction inside your engine due to ur oil. Synthetic motor oil is recommended in almost every new car today. Although, most dealerships do not use it, cause it is very expensive.
Slug build up from your motor oil would cause the valve's to "tap" more.I would flush the engine using [http://www.auto-rx.com/index.html Auto_Rx Engine Cleaner].Then use a Quality Synthetic. Good Luck and Remember.Change Your Mind, Not Your Oil.Use the First In Synthetic Motor Oil's.See My Bio For Information & Contact Details.
For the first 1600 km's or 1000 miles on a new engine just use regular oil. The reason being is that you want MORE friction in the engine to help the parts wear properly for a good "break in", synthetic oil has such good lubrication properties that it can interfere with proper engine break in.
It's time for a new engine.