When the engine is revved sligtly, ie 2k, the engine shakes. Can this caused by a sticky valve, leads breaking down, 1 piston not fully working, or something else.

OR

Is this normal for a Scooby.

CAR - Impreza Turbo MY99 - V Reg

Cheers

 

mine shakes if rev it quick from idle, and, if when standing still rev to about 6000rpm and take foot off accelerator quick,

i think this is normal, saw a max'd sti7 giving it some while stationary at a recent cruise i went to, and you could see the whole car shaking!

 

ive got the same age of car
and mines shakes too..
esp at 1500 revs

i used to think it was a problem

maybe is

 

A flat four is perfectly balanced for first and second order forces. Third order forces are not balanced, and the engine tends to rock around an axis at 90deg to the longitudinal axis in the horizontal axis (i.e. around an imaginary line in the same plane as the cylinder bores). The long period of this vibration in comparison with the first and second order forces makes it more noticable at idle / low revs. This is perfectly normal.

The engine will also rock around the longitudinal axis as you blip the throttle due to torque reaction.

Hope this helps.

Cheers,

Alex

[Edited by AlexM - 3/22/2002 2:16:45 PM]

 

cheers alex!
nice explaination