Thermostat - Right direction
 

I have a 2011 4matic and I have gotten the engine light come on twice in the last 4 weeks. I pulled the code and have gotten P0128 each time. I will be buying an Wahler thermostat housing and gasket online from Autohaus two questions:

Has anyone had good results from buying a thermostat outside of the dealer?

Also I also looks like there is a pulley that needs to be removed to get the thermostat off is that so?

Any help would be greatly appreciated I'm mechanically incline just want to make sure going in the right direction in this repair.

http://workshop-manuals.com/mercedes...ons/page_6895/ + next page

http://www.new-part.com/product/merc...ler-2722000515


I did mine with this source and Kongistiger's link.... about an hour and a half...

Did mine last weekend. Really easy. Drain coolant, whilst it drains you can remove the cover, loosen tensioner, remove the idler pulley. Usually you can now remove the top hose, little screw driver to help it out can help then use a sucker to suck out the coolant in the housing to minimise the spill. Then remove the 2 e torx bolts, disconnect the electric connector by pulling the tab backwards and then pulling off the connector. Fit the Wahler thermostat making sure gasket goes on correctly, it has taps that go into the bolt holes to ensure it doesn't move. Fit in reverse order, fill the coolant back up and burp. Was around 30 mins all in.