I have a similar thing in my 2004 Renault megane it doesnt always happen but sometimes it will shudder if sat in traffic.... I think it is something to do with the timing! but not sure
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If its an auto, its low gearbox oil and the shudder is the pump cavitiating
If the trye has gone out of round (an MOT failiure ) Yes the car will shudder when driving.
being low on fluid
EXCESS GAS IS BUILDING UP IN THE EXHUAST SYSTEM. ARE YOU USEING LOW GEAR WHEN THIS HAPPENS??? BECAUSE IF YOU ARE THATS WHY.
You may need to adjust the throtle or idle of the car. In older cars this is as simple as tightening a cable. So when the car is just idling it will naturally rev higher and not stall.
It's afraid
Could be in need of a tune up.
The engine revs and car doesn't move.
There are several reasons why your car may be overheating. Check the thermostat to be sure it isn't stuck. If the car revs up and down, the timing may need to be adjusted.
It's probably the clutch.
Because it revs low when it changes gear, an automatic gearbox should change when it is around midway through the revs, you should check this the next time you drive. Then take it too a garage and ask if they could reconfigure the gearbox.
because your engine at idol revs doesnt produce enough torque to move your vehicle. when you release your clutch (i assume you are meaning in gear) you are trying to make the car move. if you let your clutch out totally, your car would generally stall, although some cars can handle the torque requirements at low revs. the rpm (revs) goes down, & the car shakes, because the engine is struggling with this problem, & the engine is atached to the car, so it makes the whole car shake.