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Solve the two most common coolant-related failures on the Audi 4.0T platform with the TGK Motorsport Coolant Reliability Bundle — combining our Billet Front Thermostat Piping Kit and Coolant Shutoff Valve Delete Kit for a permanent, leak-free solution built for long-term performance and peace of mind.
The Audi 4.0T engine is notorious for elusive coolant leaks and hidden overheating risks, often stemming from two weak points in the cooling system: the plastic thermostat coolant elbow and the vacuum-actuated coolant shutoff valve. These factory components may seem minor, but both are known to fail in ways that can lead to coolant loss, engine overheating, or even catastrophic damage — often without obvious symptoms until it’s too late.
This bundle includes both of TGK Motorsport’s billet-engineered solutions, eliminating plastic failure points and upgrading critical seals to ensure maximum durability under all operating conditions.
Front Thermostat Billet Piping Kit
The front thermostat elbow on the Audi 4.0T uses a single O-ring and a molded plastic body prone to warping and degradation from heat cycles. Over time, the O-ring loses its ability to seal — especially in colder temps — causing coolant leaks that are difficult to trace.
Our billet replacement elbow is CNC-machined from 6061-T6 aluminum and designed with a dual-gasket sealing system, ensuring redundancy and long-term leak prevention. This upgrade eliminates the guesswork from diagnosing cold-start coolant leaks and provides a rock-solid solution for a known problem area.
Coolant Shutoff Valve Delete Kit
The OEM vacuum-actuated shutoff valve is designed to block coolant flow at cold start to help the engine warm up faster. However, it’s also known to fail in the closed position, preventing coolant from circulating entirely — a dangerous failure that can cause severe overheating.
Our delete kit removes this weak point altogether, restoring full-time coolant flow and simplifying the cooling system. Machined from 6061 billet aluminum, it ensures optimal cooling performance and eliminates the risk of a failed shutoff valve taking out your engine.
Why Upgrade Both?
By addressing both failure points in a single upgrade, the TGK Motorsport Coolant Reliability Bundle ensures your 4.0T’s cooling system is prepared for daily driving, spirited use, or demanding track conditions. Whether you're troubleshooting a persistent leak or doing preventative maintenance, this bundle provides a permanent, performance-focused solution for one of the engine’s most vulnerable systems.
