Hi have an volvo c30 1.6 petrol 2008.

problem : when accelerate in second gear (normal not slow) car unevenly shuddery moves forward.. When its past like 2,5k rpm ist like okay. With other gears no problem at all. If i accelerate harder shuddering becomes more noticable.

But sometimes its like fine, usualy when i just taken the car or when i just give the gas in first gear till around 3k rpm. and then shift second its okay
But when the car is full with my friends no matter how hard i start in first gear, when putting in 2nd and accelerate i will feel the vibe a lot. Its like shuddering forward, then i put in 3rd ands its perfectly fine.
i know i shift at enought rpm, thats not the problem.

changed spark plugs, filters etc, --nothing..

i know it should go smooth in every gear but 2nd gives me this problem around 20 - 40 km/h .Have no idea

could be drivetrain shaft problem or just problem in gearbox ? could be the fluid ? Mounts ?

cheers guys.

p.s. where is the fuel filter located for this car ? in the gastank ??

 

easy fix - just keep the rpm above 2k after 1st gear switch to 2nd.
That means need to drive in first till around 3k rpm and then switch