2017 GLS550 Turbo A Underboost CEL

[rpaoness]

For the purposes of this week's engine removal, awesome - I have none of that stuff.

[rpaoness]

Overall removal went pretty uneventfully. Took probably 4.5-5 hours total. Includes me setting up and running my R134a recovery pump for a while. I tried to clean up the shop ahead of time and keep workbenches and tools organized, so that helped beyond my normal disaster of disorganization.

Only semi-hang up was that because I decided to hold the powertrain on jackstands, I couldn't roll it forward the 1-2 inches that would've been better for getting off the end of the driveshaft. While raising the body (lowering the drivetrain), the driveshaft hung up and lifted the transmission tail/rear cross member some before we realized it was hung up. Got a prybar and pushed it apart axially and it finally cleared and everything else was good.

Looking into the turbo, looks like just the passenger one is shot, not the drivers. And I think I only need to install the kit - I don't see any evidence of cracks. I would like a second opinion and assistance in putting together a shopping list for anything else that I should install while I have the powertrain out if you have any time tomorrow to look it over.

[rpaoness]

I stand corrected - while the drivers side is still tight enough to permit full closing with vacuum applied, the pivot is worn/wobbly. I’ll do at least the kit on both sides.

[kevm14]

Parts (ideal when engine out)
Oil centrifuge cover A2780100431 $121 https://www.mercedesbenzpartsshop.com/o ... 2780100431
Pass turbo lower coolant line 2782000800 $68 https://www.mercedesbenzpartsshop.com/o ... 2782000800

Parts (can do later)
Reseal both cam phaser covers
Reseal oil filter adapter/housing since it has to be removed anyway
Replace all four cam adjuster magnets (due to O-rings failing)
Reseal oil cooler (on timing cover)
Breather tube A2780180212 $34 https://www.mbpartsgiant.com/genuine/me ... 2780180212
The intake molded boot if cannot separate from tube A2780941391 $122 https://www.mercedesbenzpartsshop.com/o ... 2780941391

[rpaoness]

Ordered the centrifuge cover and the coolant line. Hopefully shipping is faster than the 6/20 delivery they listed.

[kevm14]

I mean if Mike is on vacation that alone will delay it. You could call Norbert tomorrow and inquire about your situation and I'm sure they'll do the best they can to help you.

[kevm14]

From today

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[kevm14]

Might be good as a last check to connect the vacuum pump to the upstream Y of the vacuum harness. Activate both wastegates at the same time and confirm they are consistently reaching closure at the same time.

[rpaoness]

Yeah - something else that aids your argument that they need to set "correctly" is that exhaust gas is pushing the valve open, so if one were to set the actuator such that 24"+ of vacuum closed it, there would be no reserve actuator force available to overcome the potentially 10psi of pressure force pushing the valve open. So dead/cold/no boost, it should take fewer "s to make it close.

[rpaoness]

Says it shipped, no tracking info yet though. https://tools.usps.com/tracking/9434636106059278849903,