Nissan Ga15 engine

I have problems with my Nissan Sunny Ex Saloon engine a month ago they repaired the entire engine but what is everything.
He got out of the workshop but when it runs good section, he starts to throw white smoke and if the speed decreases it is normalized but in what smokes smoke me oil.
They opened it again to the cula they changed the guides and the seals but is still the same as it can be passing already crazy?

Hello, you will see me if the pistons are new, if not you can have problems in the guides of the piston segments the segment seat very spent greetings

Thank you for Repander I tell you the pistons are all new as the rings fallen so that it is standard.
thank you

rectified the shirts? If everything is fine and changed, you have to shoot so that everything is done, that is, to manage it normally preferably without passing 2500 rpm, for a period of 1000 kilometers before saying if something is wrong, but if what burns is oil, keep in mind that if your engine repaired it already when it was burst it can only be residues in the exhaust line.

Thank you for repander, the truth is no longer an idea because it makes this to smoke it as you mention almost like 2000 km between 60 and 70 km but this engine continues to throw smoke disassembled all the escape to see if it has waste but nothing is all normal, I repeat it is only when I give it in a straight line at a constant speed I generate this problem.