WrenchWench

So, I had engine trouble codes, P0299 (turbo under boost), P1190, and P1523, and I decided to take the car to the shop for a smoke test/diagnosis, which was overpriced, but a timesaver. They call me back, and tell me the issue is the turbo wastegate (likely, the spring or the diaphragm are busted), but they're not sold separately from a whole new turbo kit, and with parts and labor, it would be $3700 to fix...

I said, F that, tried to find it separately online and could only find Amazon aftermarket ones for $30-40. I was skeptical, but I figured, for $40, I could test it out.

The work to replace the part was super simple and I was able to do it within an hour or so, and I'd tested the old part (it was busted; didn't hold a vacuum), and I tested the new part (held a vacuum), before installing it.

Unfortunately, my OBDII scanner couldn't clear the permanent P0299 code, so I drove it awhile, and nothing changed.

Well, I decided to start replacing sensors, and the easiest route was to go to the MB dealership near my house, and offhandedly, I asked them about selling that part separately, as I was somewhat apprehensive about using cheap parts on a German vehicle (I kept thinking the spring PSI may be different and operate outside of the MB appropriate pressure sensor ranges), and the guy said, "Yes, we do! We used to not sell it separately, but we just started getting them in, but even we can't click on it on the website to select it, but we can sell it to you."

I ditched the sensors idea/rabbit hole, forked up $200 (painful vs $40, but it was worth it by this point), then I went home, replaced the part, cleared the codes, let the car sit for a couple of minutes while I worried I just wasted $200, and restarted the car.

It idled like garbage for 5-15 seconds, then it regulated itself, and it started idling smoothly...I looked at the dashboard, and no check engine light! I'm still anxiously waiting for the check engine light to re-appear, but I'm hopeful my 2018 C300 (M274) was just not liking the cheap part, and all is good on my turbo now!

I took a picture of the part (the MB one I replaced) and box (with the part number) to share with y'all, in case it helps someone. $200 vs $3700, imo, is worth it.

Thanks to everyone who posted before me, as I've been googling like mad trying to figure out what to do. Hope my post helps y'all!

Mercedes wastegate/vacuum cell

Replacement part info

PeterUbers

Good stuff

Faast

What scanner do you have that clears the CEL? I have a Foxwell nt 530 and I can't/don't know how to clear the CEL?

JettaRed

iTrader: (1)

Are you saying you don't know how to clear codes, or that your efforts fail? What code are you trying to clear? Is it CURRENT or STORED? Does your Foxwell NT530 have the BENZ software?