{"product_id":"for-subaru-ej20-ej25-engines-cylinder-4-coolant-mod-cooling-mod-kit-for-subaru-wrx-sti-forester-xt-legacy-gt","title":"Cylinder 4 Coolant Mod Kit for Subaru EJ20 \u0026 EJ25 Engines","description":"\u003cp\u003eCylinder 4 cooling imbalance has long been a known weakness on turbocharged EJ-series engines. This Cylinder 4 Coolant Mod Kit is designed to improve coolant circulation at the rear of the cylinder head, helping reduce heat concentration that can contribute to knock, ringland failure, and long-term engine stress.\u003c\/p\u003e\n\u003cp\u003eBy rerouting coolant flow from the rear of the cylinder head into the heater core circuit, this kit balances cooling between both sides of the engine. The result is more consistent operating temperatures, improved reliability under load, and added confidence for both daily driving and performance applications.\u003c\/p\u003e\n\u003ch6\u003eKey Features:\u003c\/h6\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved Cylinder 4 Cooling\u003c\/strong\u003e – Helps reduce heat buildup at the rear of the cylinder head.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBalanced Coolant Flow\u003c\/strong\u003e – Redirects coolant to promote even temperature distribution.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo Sealant Required\u003c\/strong\u003e – Installs without curing time or messy sealants.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable Materials\u003c\/strong\u003e – Anodized aluminum fittings, stainless hardware, and high-quality hose.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClean Engine Bay Finish\u003c\/strong\u003e – Performance-focused design with OEM-plus appearance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch6\u003eWhy This Mod Matters:\u003c\/h6\u003e\n\u003cul\u003e\n\u003cli\u003eCylinder 4 traditionally receives less coolant flow than other cylinders.\u003c\/li\u003e\n\u003cli\u003eReduced flow can lead to localized overheating.\u003c\/li\u003e\n\u003cli\u003eExcess heat increases the risk of detonation and ringland damage.\u003c\/li\u003e\n\u003cli\u003eThis kit helps equalize cooling across all cylinders.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch6\u003eSpecifications:\u003c\/h6\u003e\n\u003cul\u003e\n\u003cli\u003eCondition: New\u003c\/li\u003e\n\u003cli\u003eProduct Type: Cylinder 4 coolant modification kit\u003c\/li\u003e\n\u003cli\u003eMaterial: 6061 aluminum, stainless steel, silicone\u003c\/li\u003e\n\u003cli\u003eFinish: Anodized\u003c\/li\u003e\n\u003cli\u003eColor: Black \/ Silver\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch6\u003eFitment:\u003c\/h6\u003e\n\u003cul\u003e\n\u003cli\u003eSubaru EJ20 engines\u003c\/li\u003e\n\u003cli\u003eSubaru EJ25 engines\u003c\/li\u003e\n\u003cli\u003eWRX: 2002–2014\u003c\/li\u003e\n\u003cli\u003eSTI: 2004–2020\u003c\/li\u003e\n\u003cli\u003eForester XT: 2004–2008\u003c\/li\u003e\n\u003cli\u003eLegacy GT: 2005–2009\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch6\u003eWhat’s Included:\u003c\/h6\u003e\n\u003cul\u003e\n\u003cli\u003eEngine coolant hose\u003c\/li\u003e\n\u003cli\u003e5\/8\" barbed tee connection\u003c\/li\u003e\n\u003cli\u003e10AN to metric straight-thread adapter\u003c\/li\u003e\n\u003cli\u003e4x stainless steel hose clamps\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis coolant modification kit is an essential upgrade for EJ-platform owners looking to improve engine longevity, reduce thermal stress, and protect their investment—especially under spirited driving or boosted conditions.\u003c\/p\u003e","brand":"K2 Industries","offers":[{"title":"Silver","offer_id":45832477114602,"sku":"1005009587828640-Silver","price":59.99,"currency_code":"USD","in_stock":true},{"title":"Black","offer_id":45832477147370,"sku":"1005009587828640-black","price":59.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0477\/0427\/7142\/files\/S657dfd56ae3245b7b0a3aeba8cc46ed0b.webp?v=1776496852","url":"https:\/\/www.k2-industries.com\/en-jp\/products\/for-subaru-ej20-ej25-engines-cylinder-4-coolant-mod-cooling-mod-kit-for-subaru-wrx-sti-forester-xt-legacy-gt","provider":"K2 Industries","version":"1.0","type":"link"}