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BMW

Genuine BMW Downpipe to Mid-Pipe Exhaust Gasket N54/N55 | OEM 18307553603 | Fits 1/3/5/7 Series, X1, X6, Z4 (E82 E88 E90 E91 E92 E93 E60 E61 F01 F02 E84 E71 E89)

Genuine BMW Downpipe to Mid-Pipe Exhaust Gasket N54/N55 | OEM 18307553603 | Fits 1/3/5/7 Series, X1, X6, Z4 (E82 E88 E90 E91 E92 E93 E60 E61 F01 F02 E84 E71 E89)

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Heads-up on cancellations & returns: if you cancel an order or return an item, you won't get back 100% of what you paid. We apply a 10% restocking fee, the outbound shipping is non-refundable, and we have to pass on Shopify / PayPal payment processing fees; these aren't returned to us when we refund you. International orders also lose on exchange-rate spread in both directions. If the original packaging is damaged or missing, a reboxing charge applies. For international orders specifically, if you refuse to pay our shipping invoice or supply a prepaid label after placing the order, the same deductions apply. We're upfront about this — please be sure of your purchase before ordering.

OEM BMW exhaust joint sealing ring for turbocharged N54 and N55 engines. This factory BMW seal sits between the front pipe and centre section to create a leak-free connection, keeping boost response crisp and exhaust fumes out of the cabin. Perfect when refreshing a tired system or installing performance front pipes, sports cat systems or catless pipes on 135i, 335i, 535i, 740i, X1 35i, X6 35i and Z4 35i models.

Part number: 18307553603 - also searched as 18 30 7 553 603. Genuine original equipment for precise fit, long service life and a reliable gas-tight seal.

Why enthusiasts choose this OE sealing ring

  • Original BMW component - exact dimensions for the turbo outlet to centre pipe join
  • Prevents blow-by, soot marks and exhaust smells caused by a tired or crushed gasket
  • Ideal when fitting high-flow catted front pipes or decat systems to N54B30 and N55B30 engines
  • Keeps back-pressure and spool consistent for smooth power delivery and stable O2 sensor readings
  • Straight swap OE part - no guesswork, no trimming, no drama

We fit these in-house at MJ Modifications and they simply work. Our customers report clean flanges, zero leaks and trouble-free installation every time. If you are chasing reliability on a tuned BMW, this is the small part that makes a big difference.

Compatibility

For BMW vehicles equipped with the N54 or N55 engine only. Typical applications include:

  • 1 Series 135i - E82 Coupe, E88 Convertible
  • 3 Series 335i - E90 Saloon, E91 Touring, E92 Coupe, E93 Convertible
  • 5 Series 535i - E60 Saloon LCI, E61 Touring LCI
  • 7 Series 740i - F01, F02
  • X1 xDrive35i - E84
  • X6 xDrive35i - E71
  • Z4 sDrive35i / sDrive35is - E89

If you are unsure, we will verify fitment before dispatch. Add your UK registration or last 7 of the VIN at checkout.

What this gasket solves

  • Stops leaks at the turbo down pipe to middle section flange
  • Prevents CELs caused by exhaust leaks influencing lambda readings
  • Reduces metallic rasp and unwanted whistle from a poor seal
  • Protects your performance investment during down pipe upgrades

Fitting and support

Want it installed by specialists We can help. MJ Modifications in Warwickshire offers professional fitting for exhaust and turbo hardware. Request a quote at info@mjmodifications.co.uk.

Warranty

Two-year manufacturer warranty for UK customers and one-year for international customers when a compatible VIN is provided at checkout.

Also known as - common search queries

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