Cooling System

The 987's mid-engine layout places the radiators at the front of the car, fed by ducting from the front bumper, with coolant pumped the length of the car to and from the rear-mounted flat-six. That long plumbing run, combined with age and heat cycling, makes several plastic-and-rubber components known wear points.

Coolant

Use Porsche G40 — a pink/violet Si-OAT coolant (Zerex G40 is an OEM-equivalent). Mix concentrate 50/50 with distilled water. Do not mix it with green/blue silicate or generic OAT coolants. Total system capacity is roughly 22.3 L on manual cars and 24.3 L on Tiptronic cars (extra ATF-cooler circuit). Porsche treats G40 as a lifetime fill, but many owners refresh it every 4-6 years.

Common failure points

Water pump: the shaft bearing wears, producing a knock, pulley wobble, and eventually a coolant leak from the weep hole. Most pumps use a plastic impeller; a quality plastic impeller is generally preferred over metal, which can damage the block if the bearing fails.
Coolant expansion tank: the plastic reservoir embrittles and cracks (often at the seams and cap), progressing from a slow seep to a sudden split that dumps coolant.
Front coolant pipe (987.1): the plastic pipe's rubber O-rings harden and weep at the front of the engine; Porsche revised the part several times, and some owners fit aluminium replacements.
Radiators and condensers: front-mounted and low, they collect leaves and debris that trap moisture and cause corrosion.

Bleeding

The system must be properly vacuum-filled or bled after any coolant work — trapped air pockets cause hot spots and false overheating. Keep an eye on the level and watch for crusty residue or a sweet smell that signals a slow leak.

Sources:

Coolant

Common failure points

Bleeding

Know your car inside out.