engine

PCV Valve

for 2012 Mercedes-Benz S65 AMG 6.0L V12 BiTurbo M275 · RWD

Difficulty

Easy

Time

24 min

Tools

Steps

✓Fact-checked. Built from OLP's spec database, then independently fact-checked line by line with every correction applied. Master-tech sign-off by Chris Hackleman is queued. Cross-check torque values against the factory manual, and stop if anything looks unsafe. How our data is made.

Replace the PCV (Positive Crankcase Ventilation) valve on the M275 6.0L BiTurbo V12 engine to restore proper crankcase pressure regulation and prevent oil leaks or rough idle conditions.

Warnings

⚠Engine must be cool to the touch before beginning work to prevent burns from hot components.

ℹ️The M275 V12 has two cylinder banks; verify which PCV valve requires replacement before beginning.

⚠Do not overtighten the PCV valve as the housing is plastic and can crack easily.

Tools required

10mm socket and ratchetEssential

Torque wrench (5-50 Nm range)Essential

Flathead screwdriver

Needle-nose pliersEssential

Clean shop towelsEssential

Brake cleaner or degreaser

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Parts

PCV valve × 1 — A2750160131 or equivalent OEM
PCV valve O-ring/seal × 1 — Typically included with valve

As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.

Preparation

Allow engine to cool completely if recently operated
Park vehicle on level surface and engage parking brake
Locate the PCV valve on the valve cover of the affected bank (typically integrated into valve cover or attached via grommet)
Ensure adequate workspace around the engine bay; may need to remove engine cover panels for access

Procedure

1
Remove engine cover
Lift the decorative engine cover upward to disengage the mounting grommets. The cover is typically held by friction mounts and does not require tools. Set aside in a clean area.
2
Disconnect PCV hose
Locate the PCV valve on the valve cover. Using needle-nose pliers or by hand, carefully release the hose clamp securing the ventilation hose to the PCV valve. Gently twist and pull the hose away from the valve. Expect minor oil residue inside the hose.
3
Remove old PCV valve
The PCV valve threads into the valve cover or is press-fit into a grommet. If threaded, rotate counterclockwise by hand to remove. If press-fit, gently twist and pull the valve straight out of the rubber grommet. Inspect the mounting area for cracks or damage.
4
Clean mounting area
Use clean shop towels and brake cleaner to remove any oil residue, dirt, or debris from the valve cover mounting hole and surrounding area. Inspect the O-ring groove or grommet for damage. Replace grommet if cracked or deformed.
5
Install new PCV valve
Verify the new PCV valve includes a fresh O-ring or seal. Lightly lubricate the O-ring with clean engine oil. If threaded, hand-thread the valve clockwise into the valve cover until finger-tight, then use a torque wrench to tighten to specification. If press-fit, firmly press the valve straight into the grommet until fully seated.
Torque spec
PCV Valve8 Nm (6 lb-ft)
6
Reconnect PCV hose
Inspect the ventilation hose for cracks or deterioration; replace if necessary. Push the hose firmly onto the PCV valve nipple until fully seated. Secure with the hose clamp, ensuring proper positioning to prevent vacuum leaks.
7
Reinstall engine cover
Align the engine cover mounting grommets with their corresponding posts on the engine. Press down firmly until all grommets are fully engaged and the cover is secure.

Reassembly

Double-check all hose connections are secure and clamps are properly positioned
Verify no tools or shop towels were left in the engine bay

Verification

Start the engine and listen for any unusual hissing or vacuum leak sounds around the PCV valve area
Allow engine to idle for 2-3 minutes and verify smooth idle quality with no rough running
Check for oil leaks around the PCV valve mounting point
Rev engine gently to 2000-3000 RPM and verify no oil mist or vapor escaping from valve cover area
Use a scan tool to verify no new fault codes related to fuel trim or air metering issues

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