Hello everybody !

My name is Michael and I am the owner of a 1.6 ti-vct '05 Focus. I have owned it since summer '09 and I'm thrilled with it, except one small issue that I can't really get rid of.

When I first took it into service for oil and filters changes, the mechanic used a type of oil that wasn't suited for my car. After that, my car started making a noise at start up, especially in the summer and with a warm engine (which was diagnosed by another mechanic and after another 2 or 3 oil changes has disappeared almost completely) and a small hesitation / trembling of the engine in the 1800-2000 rpm range in 2nd and 3rd gear. It's a slight hesitation, you can't really notice it if you aren't expecting it, but I'd like my car to run smooth through the entire rpm range. I haven't managed to find out the cause of this issue, even though I went to a lot of mechanics and sincer I'm taking my car into service next month for cam belt and auxiliary belts replacement, I'd thought I could solve this issue as well.

I'd appreciate any tip or piece of advice you could give me. Thanks in advance.

The tremor os normal on the ti vct at that rev range hence no diagnosis its to do with the valves a small flat spot in the rev range best tip get a cambelt kit tensioner and belt done on the car

I can't really tell how normal that juddering is since it wasn't there when I bought the car...

Its normal if its a mild judder you notice it others wont some say its the fuel filter which cant be changed as its part of the fuel sender so some injector cleaner is best to use 1800-2000 is where the cam starts to open the intake outtake valves they improved this on the newer ti vct