BMW N55 Head Gasket & Head Stud Kit

OEM Head Gasket (BMW N55)

Genuine BMW head gasket for N55 engines (Part #11127599212). Proven reliable in high-horsepower and high-boost applications. For engines exceeding 800+ horsepower, O-ringing the cylinder head or block is required.

Cometic MLX Head Gasket (BMW N55)

A direct replacement for BMW part numbers 11127599212, 11127599213, 11127849620, and 11127849621, designed for N55B30 turbocharged inline-six engines.

Constructed with multiple layers of embossed stainless steel, the MLX gasket conforms to the head and block during the first heat cycle, creating a secure seal. The specialized ‘stopper’ layer prevents combustion seal failure by providing a torque-limiting surface.

Key Features:

• Improved sealing with proprietary coatings that create a micro-seal against fluids.
• Enhanced durability against blowouts with active spring-like layers.
• Not compatible with O-ringed or grooved engine blocks—requires smooth, flat surfaces.

Installation Guidelines:

1. Ensure all mating surfaces are clean, flat, and free of debris, oil, or coolant.
2. Align the gasket on the block without bending or twisting.
3. Install the cylinder head and fasteners, following the recommended torque sequence.
   
4. Do not use additional sealant; the gasket is pre-coated with Viton rubber.

ARP Head Stud Kit (BMW N55)

Upgrade your N55 engine with ARP’s high-performance head stud kit, a direct replacement for BMW part #11127853937. Compatible with multiple models, including:

Kit Includes:

• (14) 11mm studs
• (14) washers
• (14) nuts

This kit increases clamping force, improving head gasket sealing and preventing failures in high-boost applications. Essential for turbocharged and performance builds where higher cylinder pressures stress factory bolts.

1. To ensure proper thread engagement and accurate torque readings, clean ALL threads in the block. Chase if necessary with ARP Thread Chaser.

2. Clean and inspect all hardware prior to installation. Look for obvious defects or shipping damages, plus proper fit, length and dimension.

3. If the cylinder head studs protrude into a water jacket, lubricate the block threads of the studs with ARP THREAD SEALER.

4. Screw studs into the block “HAND TIGHT ONLY.”

5. Install the cylinder head(s) and check for binding or misalignment.

6. Lubricate the stud threads, nuts and washers with ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT.

Then install the washers and the nuts onto the studs and tighten them hand tight.

ARP recommends using the ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT that is provided with each kit as opposed to motor oil. This is due to higher friction on the studs as well as inconsistencies in the clamping force of the fasteners when motor oil or other low quality lubricants are used.

BMW N55 Applications:

1 Series

2010-2013 E82/E88 135i
2012-2016 F20/F21 M135i

2 Series

2014-2016 F22/F23 M235i
2016-2018 F87 M2

3 Series

2010-2015 E90/E91/E92/E93 335i
2012-2015 F30/F31/F34 335i
2015-2016 F30/F31 340i

4 Series

2013-2016 F32/F33/F36 435i
2016 F32/F33/F36 440i

5 Series

2010-2016 F10/F11 535i
2010-2017 F07 535i GT

6 Series

2011-2018 F12/F13/F06 640i Gran Coupe

7 Series

2012-2015 F01/F02 740i / 740Li

X1 Series

2013-2015 E84 X1 xDrive35i

X3 Series

2011-2017 F25 X3 xDrive35i

X4 Series

2014-2017 F26 X4 xDrive35i
2016-2017 F26 X4 M40i

X5 Series

2011-2018 E70/F15 X5 xDrive35i

X6 Series

2011-2019 E71/F16 X6 xDrive35i

ALPINA N55 Applications:

B3 Series

2013-2018 F30/F31 B3 Bi-Turbo

B4 Series

2014-2019 F32/F33 B4 Bi-Turbo

B5 Series

2010-2016 F10 B5 Bi-Turbo

B6 Series

2011-2018 F12/F13/F06 B6 Bi-Turbo Gran Coupe