05 e320 cdi - Thermostat replecement
 

I have new coolant in system.... can i replace Tstat--w/out draining coolant?

any advice?

Is wahler- good tstat replacement part? will it come w/ Sensor?

Yes, Wahler is a good brand and may be the brand originally installed on your vehicle at the factory. It is one unit that includes the housing and sensor. I read, perhaps on this board, that if you siphon some of the coolant out, the T-stat can be changed with little or any loss of coolant.

Here is a link to Whaler at a good price ($51): E320 CDI T-stat by Wahler

If you don't need it fast, here is a Behr (also OEM) one for about $42 shipped from Berlin, Germany!: E320 CDI T-stat by Wahler

I considered changing my T-stat when I changed my coolant at 150k. Since the maintenance records indicated it had been done once before and given how you dion't have to drain the coolant, I decided to just keep a spare T-stat in my trunk for cross country trips.

You'll have to drain at least out of the cylinder head or 1/2 off the radiator because the oil filter cap is blocking the bottom bolt and the thermostat housing from been removed, and When you remove the thermostat the coolant will come gushing out of the cylinder head and straight into the oil filter housing.

Yes...just drain the expansion tank.

Watch this DIY video by Josh8loop.

https://www.youtube.com/watch?v=jiV9uhjwTQQ

Thanks!