6X OEM BOSCH Fuel Injectors 7531634 Fits 06-12 BMW 3.0L X3 X5 Z4 328i 328xi 528i

KOEED · Automotive Fuel System · Bosch Port Injection · In stock

What Are the 6X OEM Bosch Fuel Injectors 7531634?

This is a set of six (6) OEM Bosch fuel injectors, part number 7531634, supplied as factory-new units. These injectors are the correct port-fuel-injection component for the BMW N52 and N51 3.0-liter naturally aspirated inline-six engines produced between 2006 and 2012. Bosch manufactured these injectors as the original equipment supplier to BMW, so the part is dimensionally, electrically, and hydraulically identical to the injectors installed on the assembly line in Munich and Spartanburg. The 7531634 is an EV6-style solenoid-actuated pintle injector with a multi-hole nozzle plate designed to deliver a conical spray pattern optimized for the N52's intake port geometry and tumble-flap airflow characteristics.

In short: If your BMW N52 or N51 engine is showing lean-bank codes, rough cold idle, or misfires on specific cylinders that follow an injector swap, a fresh set of six OEM Bosch 7531634 injectors restores the factory fuel map — same spray pattern, same dead-time latency, same flow rate the DME was calibrated for.

Why the 7531634 Injector Matters on N52 Engines

1. Matched to the MSV80 / MSD80 DME Fuel Map

What it means: The Bosch 7531634 has a specific injector dead-time curve (opening latency versus battery voltage) and a static flow rate (grams per second at 3 bar fuel pressure) that are baked into the BMW DME calibration tables. Aftermarket injectors with different dead-time or flow characteristics cause fuel-trim drift because the DME thinks it is commanding a certain pulse width for a given mass of fuel, but the actual delivered mass is off by 5-10 percent.
Why it matters: On N52 engines, long-term fuel trim (LTFT) corrections beyond 10 percent trigger check-engine codes (P0171/P0174 lean bank 1/bank 2) and can mask other underlying problems — vacuum leaks, failing MAF sensors, weak pre-cat O2 sensors.
Result: Drop-in replacement that does not require DME re-calibration — fuel trims return to the near-zero range they were at when the engine left the factory.

2. Multi-Hole Nozzle for Cold-Start Emissions

What it means: The injector nozzle plate has multiple precisely-drilled orifices (typically 4 to 6 holes depending on the exact Bosch sub-variant) that atomize fuel into a fine, evenly-distributed cone that mixes with intake air before entering the combustion chamber — even during cold enrichment when fuel vaporization is poor.
Why it matters: EU5/LEV-II emissions compliance on the N52 engine depended heavily on cold-start fuel atomization. A worn or partially-clogged injector nozzle drips fuel rather than spraying it, leading to unburned hydrocarbons, cold-start misfires (P0300-P0306), and failed emissions tests.
Result: Clean cold starts with stable idle within seconds of cranking and no raw-fuel smell from the tailpipe during warm-up.

3. Complete 6-Piece Set for Bank-Balanced Replacement

What it means: This listing provides all six injectors in one purchase — not an odd count that leaves you mixing old and new injectors across the two cylinder banks.
Why it matters: Replacing only the injectors on the faulted bank (cylinders 1-3 or 4-6) while the other bank runs 150,000-mile originals creates a fuel-delivery imbalance between banks that the DME will chase with split fuel-trim adaptation. Over time, the new injectors on one bank and worn injectors on the other create a persistent bank-to-bank AFR difference that degrades catalytic converter efficiency and fuel economy.
Result: Balanced fuel delivery across all six cylinders from day one, with even long-term fuel trims on both banks.

Verified Vehicle Compatibility

Always confirm part number fitment by VIN. The N52 was produced in multiple variants (B25, B30) and some markets received the N53 direct-injection engine instead of the N52. The 7531634 injector is a port-injection component — it does NOT fit N53, N54, or N55 direct-injection engines.

Key Specifications

When to Replace All Six Injectors (Not Just the Faulted One)

• Persistent P0171 + P0174 (lean both banks): If fuel trims are climbing on both banks simultaneously, the problem is likely under-delivering injectors across the entire set — not a single-bank vacuum leak
• Cylinder-specific misfires that move with the injector: If you swap injectors between cylinders and the misfire follows the injector, that injector's flow rate or spray pattern has degraded
• Hard cold starts with rough idle for 30-60 seconds: Leaking pintle seats allow fuel to drip into the intake port after shutdown — on the next cold start, that cylinder is flooded and misfires until the excess fuel clears
• Fuel odor from the oil dipstick: Leaking injectors wash fuel past the piston rings into the crankcase, diluting the oil and reducing its lubricity — a set replacement is urgent
• Preventative at timing belt / water pump service interval: On N52 engines approaching 120,000-150,000 miles, replacing the injector set while the intake manifold is off for the starter or PCV job saves labor hours

Frequently Asked Questions

"Do these Bosch injectors require coding or programming after installation on my BMW?"

For the N52 port-injection engine, the Bosch 7531634 injectors generally do NOT require individual injector calibration coding (IQA/Injector Quantity Adjustment) — unlike the piezo direct injectors on the N54/N55 that each carry a unique flow-rate code printed on the injector body. The N52 DME uses a common injector characterization table for all six injectors. That said, we recommend clearing fuel-trim adaptations (using INPA, ISTA, or a capable third-party scan tool) after installation so the DME re-learns short-term and long-term fuel trims from the baseline calibration rather than carrying over old trim data from the worn injectors.

"I pulled one injector and it says a different BMW part number — is the 7531634 still the right one?"

BMW used multiple OE part number revisions for N52 injectors over the production run (2004-2015, including the N52's lifespan in the 1 Series and 5 Series). Bosch supplied all of them under the same 7531634 Bosch manufacturing number. The BMW label on the injector body may carry different BMW-internal part numbers depending on the model year and supply-chain revision, but the Bosch 7531634 is the factory cross-reference. Send us a photo of your old injector showing the BMW label and we will confirm compatibility before you order.

"Should I replace the injector seals and decoupling rings at the same time?"

Yes — always replace the upper and lower O-ring seals whenever an injector is removed from the fuel rail and intake manifold. The old seals harden with heat cycling and will not re-seal reliably. If your N52 uses plastic decoupling rings (small spacers between the injector tip and the intake port bore), inspect them for cracking and replace as needed — they prevent false-air ingestion around the injector tip, which will cause lean misfires that look identical to injector failure. KOEED can supply the seal kit with the injector set — mention it in your RFQ.

"I have an N51 SULEV engine — does this injector still apply?"

The N51 is the Super Ultra-Low Emission Vehicle variant of the N52, sold primarily in California-emissions and Northeast-green-states markets. The fuel injectors are physically interchangeable between N52 and N51 — the Bosch 7531634 fits both. The differences between N51 and N52 are primarily in the emissions equipment (secondary air pump, radiator with a special coating, different DME calibration), not in the fuel injector hardware. Confirm your engine code from the under-hood emissions label or VIN decode to be certain.

"Can KOEED supply just one or two injectors instead of the full set of six?"

This listing is for the complete 6-piece set. For individual injectors or partial sets, email your requirement to Moritta@KOEED.COM and we will check individual-unit availability. We strongly recommend replacing all six injectors together on high-mileage engines — but we understand budget and diagnostic constraints, and we can accommodate smaller quantities when stock permits.

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