Parts for your 2008 Subaru Forester-Radiator

2008 Subaru Forester Radiator — What it does and how to look after it

Yes, a radiator is absolutely used on the 2008 Subaru Forester. Technical references including the Subaru 2008 Forester factory service manual (Cooling System section), Subaru Technical Information System (STIS), and OEM parts catalogues confirm the SH-chassis Forester runs a liquid-cooled EJ-series engine with a front-mounted aluminium crossflow radiator. On most automatic variants, the radiator also houses an internal transmission fluid warmer/cooler.

In everyday driving, the radiator’s job is to shed the engine’s heat into the airstream so the Forester stays in its happy temperature window. Coolant cycles from the engine to the radiator, gets cooled by airflow and the electric fans, then heads back through the thermostat to keep the temperature steady—whether it’s a quick school run or a long haul up the Kaimai Ranges.

As part of routine servicing, it pays to give the radiator and cooling system a bit of love. A clean, leak‑free radiator reduces overheating risk, protects head gaskets, and helps the heater work properly in winter. Subaru-approved long‑life coolant is a must, many 2008s originally ran green long‑life coolant (often serviced at about 5 years/125,000 km), while later services may use Subaru Super Long Life Coolant (blue), which can have longer intervals. Always follow the service manual schedule for the specific vehicle and driving conditions.

• Inspect for seepage, white/green crust on end tanks and cores, and swollen hoses.
• Check the radiator cap (around 1.1 bar spec). A tired cap can cause boiling and overflow.
• Ensure both fans cycle on with A/C and at temperature. Slow or dead fans cause hot-running in traffic.
• Use the correct premix ratio and bleed air properly, EJ engines don’t like air pockets.
• For autos, inspect the integrated trans cooler connections and keep ATF and coolant strictly separate.

If replacement’s on the cards, it’s straightforward for a competent home mechanic: let it cool, drain the system, remove the fan shrouds, disconnect upper/lower hoses (and ATF lines on autos—plug them), lift the radiator out, transfer rubbers and mounts, refit, and fill with the correct Subaru-spec coolant. Bleed with a spill-free funnel, run the heater on, and verify both fans cycle and there are no leaks. Expect about 6.5–7.0 litres capacity depending on engine and transmission. If unsure, a trusted workshop can pressure-test, flush, and replace the unit without any fuss.

Popular questions about 2008 Subaru Forester radiators

What coolant should be used, and how much does it take?
Subaru-approved long-life coolant is recommended—many owners now use Subaru Super Long Life (blue) or the specified green long‑life equivalent that meets Subaru specs. Capacity is typically about 6.5–7.0 litres depending on transmission and exact model. Always follow the owner’s manual or service manual for the correct spec and interval.

Do automatic 2008 Foresters have a transmission cooler in the radiator?
Most auto models run an internal ATF warmer/cooler inside the radiator end tank. When replacing the radiator, disconnect and cap the ATF lines carefully, avoid contamination, and check for any signs of cross‑contamination (milky ATF or coolant) which would require immediate attention.

How often should a radiator be replaced?
There isn’t a fixed replacement interval. Replace the radiator if there are leaks, cracked plastic tanks, blocked cores, overheating, or persistent coolant loss. Regular inspections and timely coolant changes will help the original radiator last much longer.