Jamie picked up the part at the Post Office since it was registered mail and no one was home when they tried yesterday.[ ]- Inspect vacuum pump check valve. I already bought a new one from Ukraine for $40. I'll be here in a month and a half. If mine is failed probably clean out the vacuum line and wastegate solenoid. I can also check for wastegate rod rattle at idle or when I press the brake pedal. I have no clue if mine is good or not but just adding this as a line item to check (I love my PM). UPDATE: I think I heard it rattle this morning in traffic so I hope the check valve arrives from Ukraine sooner than May. This issue can impact the way boost is delivered, particularly at lower RPM.
Looks...good.
Access is a little tight but nothing I haven't experienced a million times. This is easy, really. Honestly the hood service position was a big help considering this was at the back of the engine.
Slide elbow off valve, slide plastic line out of elbow, remove screw, and the check valve just comes out of the vacuum pump. I saw no oil in the waste gate solenoid line and also blew it out with air. Seemed fine.
Inspection of the old valve and elbow.
Visually, they both actually look perfectly fine. The mouth/suck test on the check valve also suggests the valve was perfectly fine. Yay? I think this car had a vacuum pump at some point, quite possibly because Mercedes doesn't actually sell this valve separately (or some other issue).
Time for a road test. I discovered this car seems to have the Mercedes-equivalent of Competitive Driving Mode, which GM pretty much invented over 20 years ago. Press once for "Sport" mode. Press and hold for T/C off.
Anyway, what's the verdict? It drives well. I will have to drive it more (including a cold start) to really see if that surging is gone or not. Maybe false alarm? I kept the old stuff because it quite possibly was totally fine.
I will have to try the brake test to see if the waste gate actuator rattles. I swear I heard it once before but never visually verified. I will have to do that and at least verify that the issue is not present (regardless if it was there before).
98,8xx miles.