Hello All,
I've been having trouble with my egr valve since way back when; yesterday, I bought some vacuum tubing by the foot and decided to replace all the old tubing up to the egr, and all under the hood as most of it was in pretty bad shape. I applied vacuum to the egr valve and audibly heard it click, so hopefully no problem there mechanically, other than it codes and doesn't seem to work when called for. While replacing tubing on the right side of engine, (facing engine compartment), I noticed a small circular valve with an inlet and outlet tube, and removed it to replace the tubing. Now, can someone tell me the correct orientation of this vacuum check valve as I think it's been installed upside down this whole time, (blue side up, black side with white numbering down), and if this has been the problem with the egr the whole time. If this is the case, it's just another reason to NEVER take it back to the local Mercedes dealer again, on top of the list of reasons I already have to never return. I'm still completing other retro-fits, and haven't started the car yet, so any input would be greatly appreciated.
Thanks,
E 320