What Exactly does Adjusting the Valves Do?
 

Does it prolong the engine? Make it run quietier? Get better fuel consumption? Exactly what is it suppose to do?

What if it is done incorrectly, what damage can result from that?

Thanks

Gray 1985 300D

First, Yes.

Second, $$$.

Valves that are too tight means valves do not close all the way resulting in lower compression, which leads to increased fuel consumption, carbon build up, burned valves, and in extreme cases, piston and valve contact.

Valves that are too loose does not allow proper air intake and poor exhuast expelling. Again, poor fuel economy increased carbon buildup from unburned fuel. If carbon gets trapped on the valve seat, theheat from the premarutely escaping gasses can also burn a valve.

Too much carbon chokes the entire intake and exhaust systems, blocks the prechamber and glow plugs, amoung other things.

Whiskey Dan gave you the condensed version, which is extremely accurate.

ditto with Whiskeydan and RR Grassi...........think of those valves as valves of a human heart! They control the flow of oxygen rich blood and also the flow of oxygen depleted blood. If the valves don't orchestrate opening and closing on time or don't fully open or close then efficiency is lost and you are fatigued because of oxygen deprivation and a build up of waste products in your system.;)

Thats my last Friday lecture!

Cheers from sunny Cape Cod

Is there a DIY link for the adjustment?

yep...
http://www.dieselgiant.com/valveadjustment.htm