The Radiator Is 2WD Specific

The 2RZ radiator is a 19" x 25" x 1" core for two-wheel-drive trucks, which is where most 2RZ Tacomas live. It is an OE-spec replacement with a single-row aluminium core and plastic tanks.

Measure your existing core before ordering. The larger 21" and 23" cores used behind the 2.7 and 3.4 are different parts.

Water Pump — Do It With the Timing Chain

The water pump is a new OEM-quality Japanese unit and the gasket is included.

Fit it whenever you do the timing chain. Both live behind the same front cover and the labour is almost entirely shared. Replacing the pump six months later means paying for that teardown twice. A spare gasket is available separately.

The 180-Degree Thermostat

The factory thermostat opens at 195°F and cycles fully open and fully closed, which swings coolant temperature rather than holding it.

The 180-degree thermostat runs cooler and, more usefully, holds temperature more consistently. A cooler, steadier engine means a denser intake charge and longer component life.

Buy the gasket with it — thermostats do not include one, and the round rubber housing gasket is what stops it weeping.

Fans

The 16" Flex-a-lite flex fan flattens its blades as engine speed rises — maximum airflow at low rpm where you need it, minimum drag at highway speed where you do not. Less parasitic loss at cruise means slightly more power and slightly better economy, and the low-rpm airflow is what a towing or crawling truck actually needs.

A flex fan needs a spacer to sit at the right depth: buy the fan and 3" billet spacer together, or the spacer separately.

Running the factory dual electric fans with one damaged blade? The replacement blade is sold individually — far better than buying the whole assembly.

Caps

The 1 3/4" radiator cap is a Sankei OEM-style Japanese part, stainless, rated at 13 lb (0.9 kg/cm²). Toyota used two cap sizes — a small 1 3/4" and a large 2 1/4". Measure rather than assuming.

If It Is Running Hot

  1. Cap. One that will not hold pressure lowers the boiling point of the whole system. Cheapest part here.
  2. Thermostat. A tired one sticks part-closed.
  3. Water pump. Eroded impeller vanes move less coolant while looking fine.
  4. Airflow. A clogged core or a fan not moving air at low speed.
  5. Then the radiator.

Hot only when crawling or towing is an airflow problem. Hot at highway speed is a flow or capacity problem. Tell us when it happens.

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