Used Alfa Romeo 155 Door Lock Mechanism

You need to confirm the side — NS (nearside, passenger left) or OS (offside, driver right) — and the year of your car, as the 155 was produced from 1992 to 1998 and there are differences to be aware of across that production run. The 155 was only ever made as a four-door saloon, so door count is not a variable here, but side is critical as NS and OS mechanisms are mirror images of each other and are not interchangeable. Give the breaker your full registration so they can cross-reference the exact spec of your car.

The 155 received a facelift in 1995 which included exterior and interior updates, and it is not certain that door lock mechanisms are fully interchangeable across this boundary. Name the boundary to the breaker — pre-facelift (1992–1995) versus post-facelift (1995–1998) — and ask them to confirm compatibility against your specific registration before purchasing. Do not assume a part from either era will simply swap over without checking.

No, the engine makes no difference to door lock mechanism fitment — whether your 155 has a 1.8, 2.0 Twin Spark, 2.5 V6, or any other variant, the mechanism is determined by the door and side, not the drivetrain. Trim levels on the 155 — such as the base, Lusso, or Q4 variants — do not alter the door frame or lock mechanism fitment either. You may find cosmetic differences in interior hardware finish between trims, but the underlying mechanism should correspond to the same side and production period.

No, NS (nearside, passenger side) and OS (offside, driver side) door lock mechanisms are handed — they are mirror images and will not work if fitted to the wrong side. Always specify clearly which side you need when contacting a breaker, and double-check this against your own car before ordering. Fitting the wrong side is a common and avoidable mistake.

The Q4 was a four-wheel-drive variant of the 155 saloon but shared the same body shell and door structure as the rest of the 155 range, so the door lock mechanism fitment follows the same rules — side (NS or OS) and production period are what matter. The Q4's drivetrain differences are entirely mechanical and have no bearing on door hardware. Confirm with the breaker against your registration to be sure, but you should not need to seek out a Q4-specific part.

Year does matter because the 155 ran from 1992 to 1998 and the 1995 facelift introduced changes that may affect parts compatibility, including potentially door components. While some parts from across the production run may interchange, you should not assume this is the case for the lock mechanism without checking — tell the breaker both your car's year and registration and ask them to confirm the part is from a compatible year. Buying a part from the correct era of production is the safest approach.