Irregular sound of injectors in Chevrolet Optra

Good afternoon friends, I would like someone to be an annoying matter in my Chevrolet Optra.

It turns bought that bought this car with 33000 km. He used 10W30 oil on the recommendation of the manual, he decided Motor to the pretext that this lubricated more, again took another concessionaire and put this type of oil again. He has a good time of this and I have a furtle sound of a Tac Tact, let's have the idea of ​​a band in which at a point in this band is something metallic and when he turns when passing through his pulley, he hits that tac tac point. I have been told that this sound is of the injectors, but before that sound was imperceptible, in addition the vehicle when it accelerates at about 1500 rpm that sound is presented.

Maybe if someone can help me, because I have a jied that it is something of the engine that begins to annoy and ends in probable repair damage.

Thanks and sorry for the discomfort
t

Hello. Look, as you explain that "tac-tac" that you hear may not be injectors, but rather of hydraulic tachys, I say it because you mentioned that they changed the type of oil they use, and with 33,000 km., It was not yet to do it yet.

Hello because with that mileage of your car you should continue using the Sae 10W-30 oil you did not have to increase the viscosity.