{"product_id":"performance-oil-pump-timing-chain-water-pump-kit-for-gmc-sierra-1500-1999-2004-5-3l","title":"Performance Oil Pump Timing Chain \u0026 Water Pump Kit for GMC Sierra 1500 (1999-2004) 5.3L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eHigh-Durability Oil Pump, Timing Chain \u0026amp; Water Pump Refresh Kit for 1999-2004 GMC Sierra 1500 (GMT800)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The Performance Oil Pump, Timing Chain \u0026amp; Water Pump Kit restores critical oil pressure, cam timing accuracy, and coolant circulation on the 1999-2004 GMC Sierra 1500 to prevent oil starvation, timing slack, and overheating under load.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock GMC Sierra 1500 Front-Drive \u0026amp; Timing Weakness\u003c\/h3\u003e\n\u003cp\u003eFactory high-mileage \u003cstrong\u003eVortec 5300\u003c\/strong\u003e engines suffer from progressive timing chain elongation, which degrades cam timing advance and causes cam sensor correlation codes. Concurrently, factory GM \u003cstrong\u003eLM7\u003c\/strong\u003e oil pump bypass valves are prone to sticking, while internal gerotor cavitation under sustained RPM drops idle oil pressure below safe operational thresholds. Paired with aged water pump bearing fatigue and leaking shaft packings, high-heat towing cycles accelerate timing cover seal degradation and risk severe engine bearing wash.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis front-engine overhaul assembly pairs a precision-machined oil pump featuring tightly toleranced internal rotors for stable oil pressure delivery across the entire rev range with a pre-stretched, heavy-duty link-belt timing chain and induction-hardened crank\/cam sprockets. The replacement water pump incorporates an anti-cavitation impeller and premium ceramic-face mechanical seal to resist high thermal loads. Complete with a front cover gasket and crank seal package, this kit locks down cam phasing and oil supply integrity under heavy-duty truck usage.\u003c\/p\u003e\n\n\u003ch3\u003eWhat's Included\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1 Oil Pump\u003c\/li\u003e\n  \u003cli\u003e1 Timing Chain Kit (chain and sprockets)\u003c\/li\u003e\n  \u003cli\u003e1 Timing Cover Gasket Set\u003c\/li\u003e\n  \u003cli\u003e1 Water Pump\u003c\/li\u003e\n  \u003cli\u003eAssorted seals and O-rings\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\n  \u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px; min-width: 300px;\"\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eFitment\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e1999-2004 GMC Sierra 1500\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eEngine \/ Chassis\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e5.3L Vortec V8 (LM7 \/ L59) \/ GMT800\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eStock Output\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e270-295 hp \/ 315-335 lb-ft\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eReplaces OEM Part #\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eN\/A\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1999-2004 GMC Sierra 1500 5.3L V8 (Vortec 5300 OHV)\u003c\/li\u003e\n  \u003cli\u003eFits GM Gen III Small Block V8 applications (4.8L, 5.3L, 6.0L Vortec platforms)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\n\u003ch4\u003eDoes this fit the GMT800 Sierra 1500?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 1999-2004 GMC Sierra 1500 equipped with the \u003cstrong\u003e5.3L Vortec LM7\/L59\u003c\/strong\u003e engine. \u003cstrong\u003eVerify your engine displacement and configuration before ordering; not compatible with Gen IV engines with displacement-on-demand or variable valve timing.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003ch4\u003eDo I need to prime the oil pump prior to first startup?\u003c\/h4\u003e\n\u003cp\u003eYes, pack or thoroughly prime the oil pump cavity with clean engine oil or assembly lubricant prior to timing cover installation to help ensure immediate lubrication pickup and prevent dry-start wear.\u003c\/p\u003e\n\n\u003ch3\u003eThe GMC Heavy-Haul Standard\u003c\/h3\u003e\n\u003cp\u003eConstructed to endure severe duty cycles, continuous payload hauling, and high-heat trailering demands, this comprehensive front-end service assembly delivers dependable oiling, timing accuracy, and thermal control for your GMT800 platform.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67545426657528,"sku":"DS-EH9U5PIRK","price":194.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/performance-oil-pump-timing-chain-water-pump-kit-for-gmc-sierra-1500-1999-2004-5-3l-1.jpg?v=1790723739","url":"https:\/\/performancechiptuning.com\/products\/performance-oil-pump-timing-chain-water-pump-kit-for-gmc-sierra-1500-1999-2004-5-3l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}