vanwiek

In the attached picture, is the device circled in yellow with MOT on the top the purge valve or "regeneration switchover valve" as the service cd calls it? On my '00 E320 you can here this device ticking and can feel it pulsating very easily. On the '94 I have never heard it or been able to feel it working. If it is what i think it is I know it deals with fuel vapor. What issues might I have if it doesn't work?

Thanks

Kestas

Been there. Charcoal finds its way down the vacuum line to the purge valve. Take it off and shake the granules out of the unit and vacuum lines.

vanwiek

Thanks, I'll try it tonight.

vanwiek

I took it out and cleaned it with WD-40 as suggested by Arthur Dalton on mercedesshop. I also hooked to to 12+ volts while it was out and it did work but with not much force. Once it was back in I stated the engine and waited until all the required conditions were met for it to activate, it never did. I then put a LED on the pins and confirmed the ECM is commanding the purge valve. I checked the codes and got nothing. Then I pulled the suction line to the valve and the valve stating pulsing, again not with much force. I am theorizing that the vacuum from the engine is to much for this weak valve to overcome and it cannot open. Although the valve technically works it is to weak to preform its function in the evap system.

I'm going to replace it.

qw35

thank mb world

notabenex

Any more info? I have same issue. Thanks

virtual_law

I know it's been 15 years but do you by any chance remember if your 'weak purge valve' theory was correct by swapping it with a new unit?