COOLING SYSTEM (Very Critical Components)
This includes the radiator hoses upper and lower, the radiator, water pump, heater hoses, heater core, thermostat, expansion tank, AC condenser fans, and intake flange kit. The cooling system has many potential points of failure and require attention in order to prevent your engine from experiencing episodes of overheating. Excessive heat is damaging to an aluminum block and many failures of start with a single failure of a cooling system component.
Radiator – We have found that the factory aluminum radiator used in the Discovery II & P38 models has more surface area than the newer aftermarket versions, so buying that $200-$300 radiator would be taking a step backwards. You need and want all the cooling capacity you can get, so don’t compromise here to save a buck. Instead, we suggest having your radiator removed and sent out to a reputable radiator service shop. They should be able to acid vat and clean your radiator and install a new inlet tank (hottest water enters this tank leaving the engine block which fatigues the plastic tank over time) for around $125-$175. In today’s market, most shops will want to sell you a new one so be aware of your options. The cooper core radiators found in the Range Rover Classic and DI’s suffer corrosion that eats away the integrity of the core making it useless and unable to be rodded. Replacing the core is the only option unless another used unit can be found and brought back to life. Flushing a radiator is different from a rodding out process. When you renew your antifreeze, flushing is sufficient but not when it comes to making sure you are back to 100% or want to know the actual condition of the radiator. If your radiator is beyond repair, replace with OE new. Never use a stop leak product in your cooling system as it does more damage than help. Address the source of the leak head on.
Small Coolant Leaks – The most common reasons for people to experience sudden overheating episodes would be the presence of a small leak. The cooling flange kit located just under the bottom side of the upper intake on the driver’s side of the engine would be a common one. The flange and sealing gasket will become corroded overtime and present a small leak. You will have the occasional smell of coolant but never see it dripping from under the truck. This leak will eventually cause you to get low enough in your system and allow air to pocket at the thermostat and not allow it to open. Another component that seems to deteriorate over time is the upper and lower radiator hose couplings. They get brittle over time and might develop a small pin hole leak. The small plastic bleeder screw in the top radiator hose can become stripped out or housing cracks. The same for the small return line coming off the radiator going back to the expansion tank. If you ever smell coolant in the cabin of the truck, feel the carpet on the passenger front floor board for dampness. A heater core or heater core o-rings can fail at any time though it is not as often as the other items covered above. The key is stay on top of your leaks by getting the truck into your mechanic when you smell coolant or notice your level is slowing going down overtime in the expansion tank.
Burping the Cooling System (awaiting content)
Testing the fan clutch (awaiting content)
Thermostat (awaiting content)
Water pump (awaiting content)
Flushing cooling lines (awaiting content)