Overheating?

[onebdi]

Hi, this may have been discussed before but I am new here and was wondering.....

There has been a lot of discussion about blocking the egr valve to reduce smoking, so I bought my ball bearing and read the bumph and the I thought...blocking the egr, in theory, means that the combustion temperature is raised as the fuel burn is more efficient. Bearing in mind that Lucidas have a bad reputation in the head gasket department, I am wondering if blocking the egr valve is going to invite overheating and headgasket problems.

Discuss and give your answers. Points will be awarded for precise information and your ability to show a good working knowledge of the subject. Points will be deducted for answering incorrectly or posting recipes for flapjack.

Thanks

[propnut]

A secondary effect of the action of the EGR valve is reduced combustion chamber temperatures. Ask yourself if you really want to block something off which is going to raise temperatures in a car that already suffers CRACKED HEADS and NOT Head Gasket problems and you can decide for yourself. There are many people who have noted the initial signs of a cracked head, have taken off the head to find the gasket ok but the tell tale signs of cracks between the valves. This nonsense about the gasket going first and then taking out the head is perpetuated by those who 1. Don't want to accept there is a fundamental head problem 2. Have a personal interest in obviating the facts.

The reason the car smokes when the egr valve sticks open is because too much exhaust gas gets past into the combustion chamber. This seriously dilutes the amount of oxygen that can be drawn into the chamber resulting in an overly rich air/fuel mix. As there is not enough oxygen to burn the given volume of fuel the excess gets ejected as black smoke. The ejected black smoke/un burnt fuel then get s sucked back into the chamber making the situation even worse and this results in a run away snow ball effect.

Elementary high school physics my dear Watson.

The EGR valve is there for a purpose rather than block it off just fit a new one or a good used one.