Labouring an engine

[obi_waynne]

What exactly happens when you labour an engine? It is clearly not happy, is usually close to stalling and there is lots of judder and vibration.

But why is this the case? What causes it and how bad is it for the engine?

 

[crowley]

That question is way to complex for me but I would say it puts a strain on the crank, because that's in direct contact with the transmission?

 

[HDi fun]

Far worse than people think. My Dad labours his cars (30mph in fifth !!!) because he believes that going over 2500rpm will kill the engine instantly. He actually thinks he is preserving the mechanical bits!!!

Four cylinder engines are less tolerant of low revs than those with five or more cylinders.

 

[obi_waynne]

I'm going on the assumption that low rpm means more vibration in the engine, you are well outside of the peak power band which can't help and the engine is desperately trying to avoid stalling under load and dumping more fuel/air.

 

[HDi fun]

I'm going on the assumption that low rpm means more vibration in the engine, you are well outside of the peak power band which can't help and the engine is desperately trying to avoid stalling under load and dumping more fuel/air.

You're totally correct. My Dad, however, sees the power band as something to be avoided.

 

[obi_waynne]

Power corrupts!