Understanding Coolant Lines
In a water-cooled Porsche engine, coolant plays a vital role—it keeps your engine running at the right temperature. That familiar pink liquid is mostly water mixed with ethylene glycol. This mix lowers the freezing point in cold weather and raises the boiling point when it’s hot, preventing your engine from overheating or the coolant from turning into gas. Since heat transfers more efficiently between a solid and a liquid than between a solid and a gas, keeping the coolant in liquid form is crucial.
Your engine is surrounded by a water jacket, where the water pump circulates coolant through the system. The coolant flows through hoses and pipes to the front of your Porsche, where the radiator cools it down before it cycles back to the engine. Typically, the system holds about 24 to 28 litres of coolant, mixed roughly 50/50 with water. The coolant lines themselves are relatively broad to ensure efficient flow and temperature management.
Coolant Connections: Where Problems Can Start
The coolant system combines rubber hoses and aluminium pipes, each joined with different fittings made from various materials. Over time, these fittings can corrode and start to leak. A common issue we fix is leaks in the coolant cross-over pipes near the front axle—this area has many joins, making it more prone to problems.
You might notice a faint sweet smell if there’s a leak, or see white crusty deposits where the coolant has dried and hardened around the joints. If you turn your steering wheel to full lock and peek into the wheel arch, you can spot black rubber pipes with these white deposits. Underneath the car, aluminium pipes run back toward the engine, hidden beneath the undertrays, connecting to fittings at the front of the engine.
The Specific Problem with Metzger Engine GT3s
This issue mainly affects Metzger engine GT3 models and involves the connection points where coolant pipes attach to the engine itself. These two large pipes are held in place by a push-fit with a C-clip. If either the pipe connection or the clip fails, coolant can spray out under high pressure—often over the rear of the car and tyres. While any coolant leak is serious, this becomes especially dangerous on track days, when you and other drivers are pushing the limits of grip. Plus, losing coolant risks severe engine damage from overheating.
The Solution: Pinning Your Coolant Lines
Though it sounds dramatic—and videos from the Nürburgring show just how messy it can get—this problem is actually quite rare. The best fix is to remove the engine and weld, or “pin,” the coolant lines to secure them permanently. Since engine removal takes about 10 hours, it’s often wise to combine this work with other maintenance to make it more cost-effective.
If you use your Porsche heavily on the track, where running temperatures soar and the risks of failure increase, pinning the coolant lines proactively is a smart preventative measure. While your car’s up on the lift, our technicians can also check the condition of all your coolant lines and connections to ensure everything else is in top shape.
