Removing Stubborn Diesel Fuel Injector Heat Shield Washers with Special Tool

Applies to all 200D 220D 240D 300D 300CD 300TD 300SD 190D 300SDL 350SD and 350SDL

Removing stuck diesel fuel injector heat shield washers can be a real challenge. This can happen if they are not changed when the injector is removed or they have been in a high mileage oil burning engine for a long time. When they are stuck, they are really stuck! The normal pick tool is just not strong enough to pop them out. Many have resorted to pry tools, heat, chemicals, and modified pliers. Heat sometimes works, but you have to be careful not to use too much heat or you can damage the seal between the pre-chamber and head. I have had limited success using strong oven cleaner and letting it soak overnight. But nothing works as well as the tool and technique I will describe here:

Problem & Solution

Common among these chassis:

W110 W111 W112 Sedan

The object is to drive something down into the center hole so tightly that it will hold to the washer when you pull up on it. If it is not too stuck you can use a flat blade screw driver and jam it into the hole as shown in these pictures. Just tap the screw driver into the center hole, twist and lift out.

If it is really stuck the screw driver won’t work. Enter the thread tap. By using just the right size you can turn the tap down into the center hole of the heat shield crush washer. Once you know the tap has a firm hold on the washer, grab the other end of the tap with a pair of vise grips and pull up hard while lightly rocking the tap back and forth.

A correct size bolt might work but it does not have the taper or the sharp cutting threads of a thread tap. Cheap tap and die sets are not expensive and they are handy tools to have in your tool box. As you can see I use them for a lot more that just cutting new or cleaning up old threads!