hey guys, does anyone of you have this trouble on your WRX? when i run on 4th gear and lower then 2k RPM, as long as i step on gas, my engine will make a ummmmmmmmm kind a viberation, it is almost as bad as you ran your car over those 1/2 inch high bumps. any idea of what is going on with that? please help. thank you million times.

 

yeah. you need to downshift. shift into 4th when you tach hits 3k minimum in 3rd.

if you wanna feel the same thing put your car in 3rd gear and try to get going from a dead stop.

 

Yah, that's your motor destroying itself. Keep the RPM's above 2K when cruising on flat ground and above 3K when accelerating or climbing hills.

 

o i c, thx guys. I used to have 91 legacy and it never does that kind of viberation. so now i got it, i know how to drive this one. thank you very much.

 

what damage does this cause to the engine?

 

Lugging means that you're calling upon the engine to accelerate from an engine speed that is well below the optimum point in the torque curve. You're asking it to do far more than it can from that engine speed (rpm). Opening the throttle even wider makes for little noticeable improvement - your engine just can't make the kind of power at that low of an rpm when under load (climbing a hill, higher numerical gear ratio). Downshift a gear or two to bring the engine speed back up into the main part of the power curve. Big trucks do this when they are attempting to travel up a steep grade like the Grapevine outside of Los Angeles.

As for what damage can be done to an engine that is lugged, probably very little in a modern engine with engine management and a knock sensor, but lugging puts a big strain on the engine components from the high load. Not good.

It's not harmful to drive a car at low rpm as long as you're not trying to accelerate. Steady state cruising at 35 mph in a WRX 5th gear is okay but you will have to downshift to accelerate quickly if the traffic conditions change.

 

lugging your engine is BADDDDDDD

 

can cause main bearing damged on crankshaft not good. Only 20hours labor + parts couple hundreds dollars

 

but if i where u i would check your driveshaft u-joint i had my bearing damaged do to salt , snow, water rusted u-joint and it would bind causing the same problem.