M157 -Race Oil Thermostat Bypass

Permanently open oil thermostat engineered for Mercedes M157 engines. Always-open design routes oil continuously to the cooler for maximum flow and lower oil temperatures during sustained or spirited driving — ideal for track-focused use where minimising peak oil temps matters most.

Key features:

Permanently open — no moving parts, zero flow restriction
Direct-fit for M157 oil thermostat housings (vehicle-specific fit required)
CNC-machined aluminum construction with corrosion-resistant finish
Lightweight, durable design built for high-temp environments

Performance benefits:

Immediate, unrestricted oil flow to external coolers — reduces peak oil temps under high load
Lowers risk of oil viscosity breakdown and thermal-related wear on track or spirited runs
Eliminates thermostat failure (no sticking/partial opening)

Trade-offs / considerations:

Slower oil warm-up after cold starts and during low-load driving — oil reaches operating temp later
Oil will run cooler than stock at normal driving
Intended for race/track use, not optimal for owners prioritising rapid warm-up or strict emissions operation

Recommended use:

Track days, racing, high-performance/spirited driving and builds with large oil coolers
Warmer countries
Not recommended as a permanent daily-driver replacement if rapid oil warm-up or factory temperature ranges are required as such in colder countries

Installation notes:

Direct-replacement design. May require new O-ring.
Verify vehicle-specific fitment, orientation before installation
After installation, monitor oil temperature and level; use a temp gauge to confirm operating range