This is a step by step guide provided to assist those who are wishing to change the coolant in their V6.
This was performed by myself on a 1997 VS V6 for those of you wanting to know. I am not a mechanic, and I will not be responsible for anything that happens if you decide to perform this task yourself. If your in doubt, have it completed by a professional. I will be happy to answer any queries any of you may have
Products for the Job
Above is a picture of the parts needed to complete the job. They include 5L of Castrol 350 Anti-Freeze, Anti-Boil Coolant, Nulon Radiator Flush & Clean, a Tridon thermostat gasket, a Dayco 91c Thermostat and a CPC 135kPa radiator cap.
Tools for the Job
Basic hand tools are nescessary to complete this job successfuly. Above is a picture of the tools that I have for the job. They include a set of screwdrivers, both flat bladed and phillips head. I also have a radiator clamp removal tool, which is ideal for those hard to reach clamps, attatched on the end, a 7mm 1/4" socket. A good quality socket set is also ideal. Pictured below is a Kincrome 1/4" and 3/8" socket set.
Step 0 - Remove the engine cover
Step 0 - Add Flush & Clean to radiator
Remove the engine cover. This is secured by 4x10mm bolts.
First of all, Undo the top radiator hose clamp, gently twisting the hose and remove it from the top radiator snout. Hold the hose upright and pour the entire contents of the radiator flush & clean in.
The level in the hose will drop, so just be patient and slowly pour the contents of the bottle in. Once the contents have been poured in, place the top hose back onto the radiator and securely tighten the clamp. This should be performed when the car is cold to prevent burning yourself. Set the heater control to the HOT position and leave them there for the duration of the time it takes you to finish the task. Start and run the engine for around 20 minutes to allow the flush and clean to fully circulate through your cooling system, including your heater core.
This product is designed to remove the rust, scale and sludge from your cooling system. I am using this product, as I know how the car has been looked after in the past. Sometimes it can be a double edged sword,
as it can remove build-up that has actually been blocking small leaks within the cooling system. This is your choice, whether you decide to use this product or not.
Once the product has been circulating through your engine for no less than 20 minutes, park the car and let it cool down for around 45-60 minutes. This prevents damaging the engine from putting cool water through the system and also minimises the chance of burning yourself! There are a number of ways to flush the engine.. I chose the most involved way, as I like to do the job properly the first time.
Step 1 - Undo radiator cap
Step 1 - Undo bottom radiator hose clamp
Remove the radiator cap. Remove the clamp securing the bottom radiator hose, enough so that you can slide the clamp down the hose without damaging it. Now the hose will have bonded to the radiator snout, so grab it and gently twist it from side to side to break the seal. When this is done, pull the hose back towards the engine. The coolant will flow, so make sure you dont have your feet in the way!!!
Step 2 - Undo top radiator hose clamp
Step 2 - Reverse flush radiator
Remove the clamp securing the top radiator hose. Remove the top radiator hose from the snout, exactly how was done when pouring the flush & clean in. Leave the hose hanging out of the way. Replace the radiator cap securely. Grab a garden hose *making sure its clean* and turn it on. Place it in the bottom outlet and block it off with your hand as best you can. Water will start to flow from the top hose outlet, continue to this process until the water flowing from the top radiator outlet is nice and clean. This process is known as reverse flushing the radiator
Step 3 - Undo heater hose clamp
Step 3 - Flush heater core
Step 3 - Desired result
Remove the bigger of the 2 heater hoses on the RHS of the engine (sitting from drivers seat). Replace the bottom and the top radiator hoses, but don't worry about securing them. Remove the radiator cap, and once again, place the garden hose in the filler neck. The radiator will fill up, then begin to circulate through the heater core. The heater controls MUST be set to HOT in order for this to work correctly! You will see all of the sludge come out of the side of the engine. Continue with this until the water flowing from the block is clear. Cover the block outlet with your hand. This will start water flowing from the hose you disconnected. Continue this procedure until the water starts to flow clear! You can do these steps as many times as you like, or untill your happy with the clarity of the water flowing out
Step 4 - Remove engine belt
Step 4 - Remove top clamp and hose
Step 4 - Remove thermostat housing
Step 4 - Thermostat housing removed
Undo the engine belt using a 15mm spanner. Press down hard on the spanner until you can easily remove the belt
Undo the hose clamp securing the top radiator hose to the thermostat housing. There are 2x13mm bolts that secure the thermostat housing to the inlet manifold. Remove these and then remove the housing from the engine. You now have a clear view of the thermostat. Remove this, noting the position it was installed. As you can see from the picture, the gasket is well and truely bonded to the housing. You will need a razor blade and some sand paper (used 150 wet and dry) to remove this. I also used a small amount of throttle body cleaner on a rag to get it looking nice and spiffy! This also needs to be done to the inlet manifold. ALL TRACES OF THE OLD GASKET MUST BE REMOVED!!! I placed an old hanky in the entrance to prevent the entry of old gasket/metal filings.
Thermostat housing with old gasket
Clean thermostat housing
Old thermostat and housing
Cleaning Thermostat housing - wire brush
Cleaning Thermostat housing - razor blade
Cleaning Thermostat housing - wet/dry sand paper
Step 5
Place the thermostat housing back, securing it with the 2 bolts. No need to worry about installing the thermostat or tightening the bolts properly for the time being, as this will be done later! Place the top radiator hose back over the housing, and remove the bottom radiator hose from the radiator snout. Turn the garden hose on and place it in the top hose. I started the engine to allow the water pump to circulate the water. This is your choice as to whether or not you decide to do this. I only had the motor running for a minute. The water will begin to flow out from the bottom hose.
Step 6
Remove the overflow bottle from the vehicle. It is only held in by 2 phillips head screws. Fill this 3/4 with water and shake violently to dislodge all the sludge contained within. Continue this process until your happy with the cleanliness of the bottle. Once complete, replace back into vehicle.
Step 7
Now that all is clean, you can begin to replace everything. Place the thermostat gasket on the housing (one side of the gasket will be adhesive)
Place the thermostat into the inlet manifold, ensuring that it is installed the correct way. Replace the housing, place the bolts back in and tighten to specific torque. I don't have access to a torque wrench, so I just ensured they were "tight"
Step 8
Replace the heater hose and secure it with the clamp. If the clamp is dodgy, replace it. Replace the bottom hose and secure it, once again, same procedure applies. Replace the top hose onto the radiator snout. Leave the top hose disconnected from the thermostat housing, as this will allow the trapped air to be bled out.
Step 9
Pour the entire contents of the 5L of coolant into the radiator, taking care not to spill any! If you do, wash it off immediately!
Step 10
Fill the radiator overflow bottle 25mm over Max, with a little coolant and water. Leave the radiator cap off and start the engine, as the coolant level drops, continue to top it up. Once the level will not go down anymore, replace the cap and observe the thermostat housing. Once coolant starts to flow from the housing, turn the car off and replace the top hose and secure it with the clamp. Start the car once more and observe the temperate gauge. Once it begins to rise, feel the top radiator hose and make sure its getting hot and building up pressure.
Step 11
Wash down the area where you have been working to remove all traces of coolant to ensure your paint doesn't get damaged!
Step 12
Take it for a test drive, ensure the temperature rises and falls on the gauge. Stop about 10 minutes after driving, pop the bonnet and ensure there is no leaks!
Step 13
Done, stop and admire the fruits of your labour!
How To Flush A V6 Cooling System
