MILIPARTS Thermostat Housing Assembly for 1.4L GM Cars — Upgraded Aluminum Direct-Fit for Buick/Chevy

MILIPARTS upgraded aluminum engine coolant thermostat housing is a direct-fit replacement designed to restore reliable engine temperature control on Buick Encore, Chevy Cruze, Sonic and Trax models.

If your vehicle is showing signs of coolant leakage, overheating, or age-related deterioration around the thermostat housing, this MILIPARTS assembly offers a durable, purpose-built option. Machined from upgraded aluminum and engineered to match OE mounting points and coolant passages, the unit replaces part numbers such as 55565336, 55579010 and 55593034 for selected 1.4L GM engines. The goal is simple: provide a long-lasting, corrosion-resistant outlet that fits without modification and helps the cooling system perform as intended.

Which vehicles and part numbers does this thermostat housing replace?

This housing was built to fit a range of GM compact vehicles that use the 1.4L engine and the same coolant outlet layout. Always cross-check your VIN or the existing part number before ordering to ensure compatibility.

• Compatible models: Buick Encore (2013–2020), Chevy Cruze (2011–2016, Cruze Limited 2016), Sonic (2012–2020), Trax (2013–2021).
• Replaces OE numbers: 25200455, 55565336, 55579010, 55593034 and related manufacturer codes.
• Designed as a direct replacement—no modifications required for vehicles that originally used these part numbers.

How does the upgraded aluminum design improve cooling system performance?

Aluminum offers improved heat dissipation and resistance to corrosion compared with many older housings made from lower-grade alloys or plastic. The upgraded construction helps the thermostat housing maintain dimensional stability under thermal cycling and resists warping or cracking that can cause leaks.

• Better thermal conductivity supports consistent coolant flow and temperature regulation.
• Higher resistance to corrosion and pressure extends service life in demanding engine conditions.
• Precision-machined mating surfaces reduce the risk of gasket deformation and coolant seepage.

Is installation straightforward and what should I check before fitting?

This assembly is engineered for direct-fit installation using the factory mounting points and connections on compatible vehicles. Replacing the housing is typically a moderate DIY job for a mechanically inclined owner or a routine task for a professional technician.

• Verify the OE number on your original part before purchasing to confirm fitment.
• Replace the thermostat gasket and hose clamps when installing to ensure a leak-free seal.
• Flush and refill the cooling system and bleed air pockets after installation for proper operation.

What quality and support can I expect from MILIPARTS?

MILIPARTS supplies this unit with attention to material selection and dimensional accuracy to match factory specifications. Customer support is available to assist with fitment questions and product concerns to help you avoid purchasing the wrong item or troubleshooting fitment issues.

• Manufactured from upgraded aluminum for improved durability and heat tolerance.
• Backed by MILIPARTS customer service—contactable for fitment verification and support.
• Storage note: keep the part sealed and dry to prevent plug oxidation when not installed.

Who is this for: This MILIPARTS thermostat housing assembly is intended for owners and technicians working on Buick Encore, Chevy Cruze, Sonic and Trax vehicles equipped with the 1.4L engine who need a direct OE-replacement housing that improves longevity and resists corrosion. If you want a precisely machined aluminum replacement that matches original mounting and coolant paths, this part is a practical choice. Always confirm your vehicle's year and existing part number before ordering to ensure proper fitment.