IsItAGoodCar
Reliability Guide

Common Problems with the
2013 Infiniti G (G37)

We've identified 2 known issues that can affect the 2013 Infiniti G (G37). 1 of these are serious faults that could be expensive to repair.

2
Known Issues
1
Serious
1
Moderate
0
Minor

All Known Issues

Heater Matrix Hose Plastic Connector Fracture

SeriousCooling System

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.

Est. Repair Cost: £150–£400
Warning Signs:

Sudden dumping of engine coolant underneath the passenger side of the vehicle, Sweet-smelling white steam billowing from behind the engine bay near the bulkhead, Engine temperature gauge needle rapidly climbing into the red zone, High coolant temperature warning light on the instrument cluster

What to Inspect:
  • Inspect the plastic heater core hose connector near the passenger-side firewall for cracking, chalking, or crusty white residue
  • Check whether the fragile factory plastic union has been upgraded to a durable brass or aluminium coupler
  • Check the coolant expansion tank level and pressure-test the cooling system for rapid pressure loss
Verified by IsItAGoodCar Research TeamUpdated

HV36 Convertible Roof Mechanism Sensor and Seal Failure

ModerateBodywork & Rust

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.

Est. Repair Cost: £400–£1,800
Warning Signs:

Folding hardtop stops moving mid-cycle and displays a roof malfunction warning on the instrument cluster, Audible chimes and refusal to unlatch or lock into the windscreen header rail, Water collecting in the spare wheel well or rear passenger footwells after rain, Damp musty smell in the cabin and intermittent sound distortion from the Bose headrest audio system

What to Inspect:
  • Operate the folding hardtop through complete open and close cycles multiple times, listening for hydraulic pump strain or hesitation
  • Inspect the boot carpet, spare wheel well, and amplifier mounting bay for signs of moisture or water staining
  • Examine the rubber seals along the roof seams and windscreen header rail for splits, flattening, or lack of lubrication
  • Pour water into the C-pillar water drainage channels to ensure water drains freely under the rear wheel arches
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 2013 Infiniti G (G37)

  • On pre-2013 3.7 V6 models, check for diagnostic fault codes P0011 or P0021, and carry out a mechanical oil pressure test at warm idle to verify oil gallery gasket integrity.
  • On G37 Convertible (HV36) models, operate the three-piece folding hardtop through its full open and close cycle, and inspect the boot floor and under-carpet areas for water ingress.
  • Inspect the plastic heater hose coupler on the passenger-side bulkhead for hairline cracks, brittleness, or dried white coolant residue, upgrading to a metal joiner where possible.
  • Examine the rear hydraulic compliance bushes on the front lower suspension arms for splitting or silicone fluid leakage, which causes motorway wandering and inner tyre shoulder wear.
  • Check the service history for regular 7-speed automatic transmission fluid changes and inspect the rear differential casing for oil misting or output seal leaks.
2012
Check a 2013 Infiniti G (G37) by Registration