Parts for your 2012 Subaru Forester-Radiator

2012 Subaru Forester Radiator — what it does, how to look after it, and when to replace it

A radiator is absolutely relevant and fitted to the 2012 Subaru Forester. Technical sources that document this include the Subaru Factory Service Manual for the 2012 Forester (Cooling System section), the Subaru Electronic Parts Catalogue for the SH series (Radiator Assembly in Section 45 – Cooling), and Subaru Technical Information System service bulletins covering the FB-series engines. These documents describe the radiator, fans, cap, hoses, thermostat and coolant specs used on the 2012 model.

On this Forester, the radiator’s job is to pull heat out of the engine coolant so the FB-series engine can run at the right temperature in Aussie and Kiwi conditions. Coolant flows from the engine to the radiator, air passes through the fins, and the electric fans help out at idle or in traffic. Keep it happy and the engine stays efficient, quiet, and long-lived.

As part of regular servicing, the radiator and cooling system deserve a quick once-over. Look for any pink/white crust around seams (dried coolant), soft or swollen hoses, oil-like sheen in the header or overflow tank, and check that the fans kick in after warm-up. Subaru’s long-life blue coolant is designed for extended service, but it still needs periodic replacement per the logbook, use the correct Subaru-spec phosphate OAT coolant and don’t mix colours. Top-ups should be made with premixed 50/50 demineralised water and the right concentrate if you’re not using a premix.

Replacement is usually on condition: impact damage, leaks from the plastic side tanks, clogged cores, or persistent overheating are the big triggers. When fitting a new unit, a quality OEM-equivalent radiator is the safe bet. For automatic models, the radiator may include an internal transmission fluid cooler—cap the lines during the swap and check ATF level afterwards. Always fit a new radiator cap and fresh hose clamps, and consider upper/lower hoses if they’re more than a few years old.

Bleeding air is critical: fill slowly with a spill-free funnel, set the heater to HOT, run the engine to operating temp, squeeze the upper hose to burp bubbles, then top the overflow to the FULL mark once it cools. After a few drives, recheck levels. If there are ongoing issues—sweet smell, bubbles in the overflow, or temp spikes—get a pressure test and chemical block test done.

• Watch-for signs: rising temps in traffic, low heater output, or coolant loss with no obvious leak.
• Good habits: annual inspections, correct coolant, clean radiator fins, and cap replacement every few years.

Popular questions about 2012 Subaru Forester radiators

How do you know the radiator is failing on a 2012 Forester?
Common clues are slow overheating at idle, coolant smell after parking, pink/white residue on the side tanks, and damp patches around the lower corners. The heater blowing lukewarm on a cold day or the temp gauge creeping up in traffic can also point to a partially blocked core or weak cap. A cooling system pressure test will usually confirm it.

What coolant should be used in Australia or New Zealand?
Use a Subaru-approved long-life blue coolant (phosphate OAT chemistry). Stick with one type—don’t mix green and blue. If you’re unsure, drain and refill with the correct Subaru-spec coolant premixed 50/50 with demineralised water. Follow the service schedule in the owner’s manual for change intervals.

Can the radiator affect the automatic transmission?
On many 2012 Forester autos, the radiator includes an internal transmission fluid cooler. A leaking internal cooler can risk ATF contamination or coolant loss. When replacing the radiator, cap the ATF lines, refit carefully, and check ATF level and condition afterwards. If in doubt, have a technician inspect for cross-contamination.