IsItAGoodCar
Reliability Guide

Common Problems with the
2008 Subaru Forester Mk2 (SG)

Final year of the SG Forester. The newest examples are now approaching 20 years old, so expect age-related wear on rubber components and suspension bushes. Well-cached examples with full service history are increasingly sought after.

What changed for 2008

  • •Final production year before SH replacement
  • •All models now equipped with ESP as standard

Common MOT watch-outs

  • !Head gasket failure on neglected 2.5L engines
  • !Self-levelling suspension complete failure
  • !Structural corrosion on chassis rails
4
Known Issues
1
Serious
3
Moderate
0
Minor

All Known Issues

Head Gasket Failure (2.5L Engines)

SeriousEngine

The 2.5L EJ25 engine in the SG XT is prone to external coolant and oil leaks from the head gaskets, eventually leading to overheating. UK MOT data records engine oil/coolant leaks and exhaust leaks as a recurring failure area on this generation.

Est. Repair Cost: £1,200–£2,000
Warning Signs:

Coolant smell from engine bay, Oil/coolant weeping at the block join, Bubbles in the expansion tank

What to Inspect:
  • Check the engine block join from underneath
  • Look for white residue around the expansion tank
  • Confirm if Multi-Layer Steel (MLS) gaskets have been fitted
Verified by IsItAGoodCar Research TeamUpdated

Self-Levelling Suspension (SLS) Failure

ModerateSuspension & Chassis

The original rear struts leak and sag over time, leaving the rear of the SG sitting low, especially when towing or loaded. Suspension is a leading MOT failure area on this generation, and genuine OEM SLS parts are expensive in the UK.

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

Rear sits noticeably lower, Bouncy ride over bumps, Fluid leaks on the rear struts

What to Inspect:
  • Check arch-to-tyre gap at the rear
  • Look for standard spring conversions as a positive sign
  • Inspect the struts for oil misting
Verified by IsItAGoodCar Research TeamUpdated

Rear Subframe and Mounting Point Corrosion

ModerateBodywork & Rust

UK road salt attacks the rear subframe and its suspension mounting points, often before the body panels look especially rusty. Corrosion around prescribed areas is a recorded MOT failure on this generation and can become structural if ignored.

Est. Repair Cost: £400–£1,200
Warning Signs:

Heavy rust scaling underneath, Corrosion advisories near suspension mounts, Seized suspension bolts

What to Inspect:
  • Inspect the rear cradle on a ramp if possible
  • Read past MOT corrosion advisories closely
  • Check for fresh underseal hiding flaky metal
Verified by IsItAGoodCar Research TeamUpdated

Exhaust System Corrosion and Leaks

ModerateExhaust & Emissions

The SG's exhaust, silencer and pipes rust under UK winter salt, causing loud blowing or rattling noises and potential MOT failure on exhaust noise, emissions or leaks. Once the car has covered high mileage on salty roads this is a common and predictable wear item.

Est. Repair Cost: £250–£600
Warning Signs:

Loud exhaust roar or rattling, Rattling from underneath the car, Failed MOT on exhaust noise or emissions

What to Inspect:
  • Listen for an exhaust blow with the engine cold
  • Inspect the silencer and pipes for rust holes
  • Check MOT history for repeated exhaust advisories
Verified by IsItAGoodCar Research TeamUpdated

Buying Tips for 2008 Subaru Forester Mk2 (SG)

  • Look for a full service history with timing belt changes
  • Check the cooling system for any signs of head gasket issues
  • Test the self-levelling suspension on a level surface
2006–2007
Check a 2008 Subaru Forester Mk2 (SG) by Registration