Subaru Repair & Service in Dubai

The boxer engine: pros and cons

Opposed pistons cancel each other’s primary forces, so the engine runs smoothly without balance shafts, and its flat shape sits low in the car — the reason the BRZ has a low centre of gravity. The costs: the engine is wide, it has two cylinder heads and two camshaft drives, and oil can collect differently in horizontal cylinders, so oil level and consumption deserve attention. Many routine jobs take longer than on an inline engine.

Spark plugs: the access problem

On a boxer the plugs sit at the outer ends of the engine, between the cylinder heads and the chassis rails. On the BRZ’s FA20 and FA24 there is very little room: the job needs thin-wall sockets, extensions and often moving intake parts or the battery tray aside. A plug cross-threaded in an aluminium head is an expensive mistake, so it is done cold, by hand-start, and to torque.

Cooling: proper bleeding

The horizontal cylinder heads trap air easily. After any coolant work the system must be bled following the procedure, with the heater on and the engine brought to temperature, until no air remains. An air pocket in a head causes local overheating and erratic temperature readings even when the expansion tank looks full.

Oil pickup blocked by sealant

Oil pans on these engines are sealed with RTV (room-temperature vulcanising) silicone instead of a gasket. On the FA24 engine in the 2022+ BRZ, GR86 and WRX there are documented cases of excess sealant breaking loose in hot oil and clogging the oil pickup strainer, starving the bearings of oil; no recall was issued. Whenever the oil pan comes off, we inspect and clean the pickup screen, and we apply sealant as a measured bead so nothing squeezes into the sump.

BRZ in depth

The first-generation BRZ (2012–2020) uses the 2.0-litre FA20 with Toyota’s D-4S port and direct injection, which limits carbon build-up on the intake valves; early cars were part of a valve-spring recall. The second generation (2022 on) has the 2.4-litre FA24 with more mid-range torque. Both are rear-wheel drive with a Torsen limited-slip differential on manual cars. On track, oil temperature, oil level and pressure behaviour in long corners are worth logging; an oil cooler and a baffled pan are common upgrades, together with brake fluid, pads and cooling.

Impreza, WRX and STI

Impreza uses the FB engines and, on recent cars, the Lineartronic CVT, which needs fluid service. Older EJ-engined WRX and STI models have their own known topics: head gaskets on the EJ25 and ring-land damage on hard-tuned EJ257s. Symmetrical all-wheel drive needs matched tyres on all four corners to protect the centre differential.