I'm hooking a MityVac up to the EGR valve on an M103 six cylinder. I'm seeing the shaft inside moving up as I pump the handle, pulls about 5 on the gauge, then slowly slips back down again. Is the valve good or bad?

Everything I've read says if it doesn't HOLD vacuum, it's bad. However, common sense tells me it's bad if it won't even actuate. It seems to be actuating fine, it just slips back down.

__________________
'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)

Should hold vacuum!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks. So mine is bad.

It's not showing a CEL - how critical is this part to passing an emissions inspection?

Considering the ridiculous cost of this part new, it would be best for me if I could get away with not replacing it.

__________________
'02 BMW 325i
'85 300D 450k
'93 190E 2.6 170k(killed by tree)
'08 Ducati Hypermotard 1100S 6k
'06 Ducati S2R800 14k(sold)