Can you go without a thermostat in a 79 300 td
 

Replacing the thermostat and was wondering if I could go without one complete? Will this cool better?

No.
Aside from keeping the temperature pretty even, another function of the thermostat is that it acts like a restrictor, i.e. it keeps the coolant in the radiator long enough to actually get cooled down by the airflow through it.
Would'nt be the first time I've seen somebody trying to rectify a small problem, only to create a much bigger one. ;)

Manny ,have you ever done a water pump on one of these ,sounds like you have to remove the harmonic balance ,is this true?79 300td

No, sorry.
Maybe if you post this in the Diesel Forum, some of the Old Smokeys over there can answer that for you. ;)

The thermostat has 2 functions.

1) To block flow to the radiator when it is cold thus allowing all the coolant to bypass and re-enter the block.

2) To block the bypass circuit allowing all coolant to flow through the radiator when the thermostat is fully open.

Without the thermostat in place, only half the coolant will flow through the radiator when the engine is hot and half will flow through the bypass circuit since the thermostat will not be there to restrict the bypass circuit.

The end result is the car will run warmer without the thermostat.

very good explanation
 

of the function of the t stat.

and i would add that it will run hot in hot weather and cold in cold weather.

definately not recommended except in an emergency and not for long.

tom w

Run one, don't try to he a hero.

You don't have to remove the harmonic balancer to replace the water pump. Not too bad a job. Be sure to replace with exactly what Mercedes calls for (gasket/pump). Nothing special, just stock.

Stay away from green coolant.

Haasman