It's a small diameter screw, easy to break if you twist too hard. Without wrenching experience it would be pretty easy to break thinking you weren't turning too hard.

When the cover is off, you (or your mechanic) might be able to use a small cold chisel to coax the broken end of the screw around enough to then grab it with pliers.

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1987 W201 190D

This is one of the few jobs that I use a torque wrench. "Inconsequentially low" will usually result in a leak..........while too tight will also result in a leak because the cover deforms.

12 lb.-ft. works perfectly. Surprisingly, it's tighter than one might expect with a 1/4" ratchet.

The Spiral ones are OK on hard bolts. But, on an extremely stuck grade 5 bolt the spiral wants to screw into it and expand it; and this can make it even harder to get out.
I also found that the Spiral ones pictured can be extremely bad to use on broken brass fittings if they are also stuck good (I used to work in a Ship Yard; every metal carodes or rust given enough time and exposure).

The newer spiral Ezee-Outs do not have as deep or as steep of a spiral and may not expand the bolt like the Older style do.

The Square ones like the ones in the picture have delicate edges that can sometimes get damaged but are great for removing broken off brass fittings.
I could not easily find a picture of the Snap-On ones but they make a Square Ezee-Out with a twist at the end that does not have the delicate edges. Those are the ones that I used most often on bolts. I tried to save my other Square ones for Brass.

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84 300D, 82 Volvo 244Gl Diesel

To be honest I've never had a 601 open...but a quick look at EPC with a VIN from another '84 190D shows hydraulic lifters.

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Dale

http://i52.photobucket.com/albums/g1...MG_2277sig.jpg

1990 300D 2.5 Turbo -155k
2000 E430 - 103k
2014 Jeep Grand Cherokee Ecodiesel 4x4 - 11k
2014 VW Passat TDI SE - 7k Bro's Diesel
2006 E320 CDI - 128k Pop's Benz

Pre-glow - A moment of silence in honor of Rudolph Diesel

I did the same thing - I lopped off the top of the bolt below the nut and then used vice grips and plenty of PB Blaster to get the bolt out of the valve cover and engine block.

BTW, even at my MB dealer (which seems to be 10-15% higher than others), the replacement parts were under $5.

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Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

I think the torque specs on those are 10 Nm.

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

I did a check and you're correct.........only 7 lb.-ft. for the 603........surprisingly different from the 12 lb.-ft. on the 617.