Replacing the Plastic Cooling System Parts on a JLR 3.0 Supercharged V6

The Jaguar Land Rover AJ126 3.0L Supercharged V6 cooling-system overhaul continues with the main component upgrades. With the supercharger removed and serviced in Part 2, we now have access to replace many of the plastic cooling-system components around the engine on my 2020 Land Rover Discovery 5. In this episode, I install a metal rear coolant crossover pipe, genuine JLR metal lower Y-pipe, a metal thermostat housing, new water pump, metal water-pump pipe and brass water-pump elbow. I also replace several of the factory coolant hoses with silicone hoses from Swallows Racing. The rear crossover pipe is the most challenging part of this job, particularly on the AJ126 V6 because of the limited access to the lower mounting bolts behind the engine. I show the tools and techniques that helped me get it out, along with several details worth checking before installing the replacement. We’ll also look at hose alignment and routing, transferring the factory coolant-temperature sensor to the new rear crossover pipe, installing the water pump and metal pipe, choosing the correct notched brass elbow, and fitting the metal thermostat and silicone hoses. While this project is being performed on a Discovery 5, much of the work applies to other Jaguar Land Rover vehicles using the AJ126 3.0L Supercharged V6. Component configurations and access can differ between applications, so always verify the appropriate parts and factory procedure for your vehicle. 🔧 In this episode: 🔩 Removing and replacing the rear coolant crossover pipe 🛠️ Working around the difficult lower AJ126 crossover-pipe bolts 🌡️ Transferring the factory coolant-temperature sensor 🔍 Checking the replacement crossover pipe before installation 📏 Transferring factory hose alignment marks to the silicone hoses 🧪 Discussing the lined silicone hoses and coolant compatibility ⚙️ Installing the genuine JLR metal Y-pipe 🔧 Replacing the plastic water-pump pipe with a metal version 💧 Installing a new JLR water pump 🟡 Installing the notched brass water-pump elbow 🌡️ Replacing the thermostat housing with a metal version 🔵 Installing and routing the silicone coolant hoses 🔄 Reinstalling the drive-belt tensioner, belt and fan pulley ➡️ Setting up Part 4: supercharger installation and reassembly With the major cooling-system components installed, the next episode moves into reassembly: reinstalling the supercharger and putting the engine bay back together before completing the cooling-system service. ℹ️ Parts & Tools Used for This Project Parts: Upper and lower crossover pipe P/Ns: LR186859, LR186917 - Use genuine if you can afford it! But if you must go aftermarket, this seems to have good reviews vs cheaper options: https://link.amazon/B0j8NWfn5 Rear crossover pipe (V8): https://link.amazon/B082D4AlX Rear crossover pipe (V6): https://link.amazon/B0770S1EK Brass elbow with notch (reuse factory o-ring!!!): https://link.amazon/B0iR5goBf Metal thermostat (V8): https://link.amazon/B08nxKylt Metal thermostat w/ wire (V6): https://amzn.to/3Snd7Q5 JLR water pump P/N: AJ813909 Metal water pump pipe: https://link.amazon/B03lff0di Silicone hoses: From @swallowsracing Supercharger gaskets (V6): https://link.amazon/B04CsgUjr Tools: Fan clutch removal tool: https://link.amazon/B04FdgCP4 Hose clamp compressor set: https://link.amazon/B0awiQ5Fi Blind box ratchet (perfect for rear crossover pipe): https://link.amazon/B0curK312 Torx bit set: https://link.amazon/B04cnCXiL 2-in-1 1/2"/3/8" breaker bar: https://link.amazon/B03CIIZie Coolant pressure test and vacuum fill kit: https://link.amazon/B0cRPSSKR Loctite silver anti-seize: https://link.amazon/B03maZSRD Gasket remover: https://link.amazon/B06QIY16B Loctite 518: https://link.amazon/B04mf4iNn Plastic scrapers: https://link.amazon/B0bQ8OKR1 Some links above may be affiliate links. I may earn a commission from qualifying purchases at no additional cost to you. Everything shown was purchased by me unless otherwise stated. ℹ️ Chapters 00:00 Part 3: Cooling System Component Upgrades 01:37 Rear Crossover Pipe Upgrade 07:41 Silicone Hose Preparation & Installation 09:44 Water Pump Removal 12:19 Installing the Metal Water-Pump Pipe 13:54 Installing the Metal JLR Lower Y-Pipe 16:25 New Water Pump + Brass Elbow Installation 19:41 Thermostat Removal 21:18 Metal Thermostat & Silicone Hose Installation ⚠️ DISCLAIMER: This video documents work performed on my own vehicle and is intended for informational purposes. Cooling-system configurations, procedures, torque specifications, parts compatibility and required disassembly can vary between Jaguar Land Rover vehicles, engines, model years and markets. Verify compatibility and refer to the appropriate factory service information for your specific vehicle before performing any repairs or maintenance.