2013 Infiniti G37 3.7L Petrol · YJ13 JEO

The factory plastic heater hose coupler located against the passenger-side engine bay bulkhead degrades and becomes extremely brittle after repeated heat cycling. At higher mileages, the plastic fractures or shears completely under coolant system pressure, suddenly venting engine coolant onto the hot exhaust and ground. Because the coolant is lost within seconds, rapid engine overheating occurs. If the driver fails to shut down the engine immediately, cylinder head warping or head gasket failure can quickly follow. Replacing the fragile plastic connector with an aftermarket billet aluminium or brass barbed coupler is a standard preventative measure amongst UK specialists.

On the G37 Convertible (HV36), the complex three-piece electro-hydraulic folding hardtop system is vulnerable to microswitch misalignment, hydraulic pump pressure loss, and weatherseal deterioration. Wear in the roof latching linkages or failed position sensors can cause the roof to stall halfway through its 25-second cycle. Furthermore, drying weatherstrips and clogged rear drainage tubes allow rainwater to seep past the C-pillar seals into the luggage compartment, soaking the boot floor carpet and short-circuiting the roof control module and the Bose audio amplifier located beneath the trim panels.