Myth? Plugged EGR burns geo metro exhaust valves?

[kamesama980]

Originally Posted by 8307c4

I don't know what exact damage it could cause but I do know EGR stands for exhaust gas recirculation... It is intended for cold engines to be able to warm up quicker for one, and if it is plugged and it stays in a closed loop then the exhaust will build up higher than normal temperatures during normal driving.

no it doesn't help warm up the engine. not in a gas engine anyway. looking through the diagrams for both cressidas I've had, it's disabled till the engine reaches operating temps.

Nor will it create higher exhaust manifold pressure either. there's this thing called the exhaust pipe to take care of that. if you clog a cat converter you can create enough backpressure to burn a valve but EGR does nothing of the sort. it's a small pipe off (usually one) exhaust port that channels a small amount of exhaust gasses back to the intake.

Originally Posted by 8307c4

The increase in temperature is minor during normal driving but can be substantial during heavy or sustained acceleration, so I do suppose high manifold temperatures could reach back towards the valves and affect them, but I don't know for sure.

again, exhaust mani pressure won't increase because of it. it does exactly what we talked about above... lowers combustion chamber temperatures.