Honda Turbo

From the 1.0 VTEC to the 1.6 i-DTEC: why the same Honda 1.5-litre engine covers four distinct turbos

The most common identification pitfall with Honda turbos concerns the engine block L15B7: this engine code is shared by three different commercial designations — 1.5 T Si, 1.5 VTEC Turbo and 1.5 Turbo — fitted to the Civic and the Accord depending on the market and the year. Yet the manufacturer references associated with this block are not interchangeable: the volute geometry, the actuator type and the CHRA dimensions vary from one application to another. Relying on the engine code alone, without cross-referencing the model and the commercial variant, will systematically lead to an ordering error.

1.5 T and 1.6 i-DTEC: two families, two failure patterns

The 1.5 T (codes L15BM and L15BN) fitted to certain Civics differs from the L15B7: two distinct codes, two distinct turbos, with no overlap whatsoever in manufacturer references. The 1.5 T is particularly prone to carbon deposit build-up in the oil circuit when used predominantly for short urban journeys, which accelerates bearing wear. The 1.6 i-DTEC 120 (code N16A1) found on the CR-V and the diesel Civic uses a variable geometry; failures on this turbo are often attributable to a clogged EGR valve or a blocked DPF, both of which cause excessive oil consumption and damage the bearings. In both cases, it is essential to identify and rectify the root cause before any replacement, otherwise a new turbo can be destroyed very quickly.

1.0 VTEC 129 (P10A2): the most recent, the trickiest to identify

The 1.0 VTEC 129 (code P10A2) is fitted to the latest generations of three-cylinder Civic. It is the most recent engine in this range and the one most commonly confused with the 1.5-litre units: different engine capacity, a completely distinct code, and specific manufacturer references. Classic symptoms across the entire range — a whistling noise on acceleration, blue smoke on start-up, loss of power or the vehicle entering limp mode — point towards the turbo, but a precise diagnosis of the lubrication circuit and intake pressure remains essential before drawing any conclusions. All turbos listed on this page are new parts, sold direct, with no old unit to return.