Originally Posted by straightboy
Love everything about my new Focus except that I was taken aback a little by rough, gentle shaking of the car when you let it creep forward with no acceleration. I first thought it might be stalling out or happening because of the strain of the A/C running. Still happens without A/C and sometimes to a small degree when you're completely stopped (foot on the brake). No change in the RPM's ever happens. Only have 200 miles on the car so I am willing to give it a little time to smooth out but I really wish it was smoother.
I've just got a 2012 Focus SE HB yesterday.
the car has a similar problem;
Drives well, but when it come to a complete stop, when rpm gradually fall just below 750 the car (or engine) starts shake (something like the engine hesitates and give impression that it is about to stall) while foot on brake. Interestingly, when A/C is on rpm keeps just around 750 and shakes less. Above 750rpm on idle there is no shake.
But the interesting thing is, I have test driven the same car before purchase and everything was so well while test driving, unlike after it is delivered.
What may change in between?
There can be many thing but first come into mind;
Does Ford use Premium gas when sending from factory, which increases performance and maybe give a smooth idle (can it make so much difference)?
Is Ford tune the engine for best mpg out of factory, or the dealership tunes before delivery (when delivered it was 30 km with 14.8 L/100km, and I know how the 20 km is spent)?
Is there anybody who has test driven the car which they have purchased and find some different experience before and after?
Is this a malfunction or just a simple fine tune, or just the matter of gas brand?
I did not find chance to consume the tank to try premium gas, but I will do so. Is there anybody who had similar problem and tried premium gas? Did this solved the problem?
I do not want to give the "brand new" to service for their experiments unless there is a real problem.