Coolant Change 

and Thermostat

Replacement

There are separate videos and guides below for replacing either the thermostat+coolant, or the coolant alone, along with consumable and part lists for each job.

With just over 150,000km on the clock, my 200 had started running slightly warmer than had typically been the case. Instead of the water temperature consistently sitting between 78 and 88º, it would typically run at 85-95º.

The coolant is due for routine replacement at 160,000km and there are some reports of a simple coolant change rectifying this issue, so I considered just replacing it and checking the results. However, the relatively low cost of the thermostat led me to replace both.

Toyota’s procedure for the basic task of replacing the thermostat is insanely complicated, involving removal of the radiator, fan, vacuum pump, transmission cooler and much more. You’re looking at a couple of days work. Fortunately, there’s no need to do any of that if you don’t mind working in the confined space between the radiator and the engine. This cuts the working time to an hour or two..

Jump to: | COOLANT ONLY | | COOLANT + THERMOSTAT |

Coolant change video

Coolant and Thermostat video

IMPORTANT

The following should not be taken as instructions. It is simply a documenting of the procedure I followed for my own servicing and maintenance. No warranty is provided as to the accuracy of the information, and/or whether it applies in your situation or to your vehicle.

There are many additional checks which take place during routine vehicle servicing. It's not just a 'grease and oil change'. You may not be aware of these checks, which could lead to component failures. I strongly recommend you have your vehicle serviced regularly by a qualified mechanic. If you're not qualified and/or don't have the correct equipment, don't attempt to perform your own vehicle maintenance.

  • There are potentially lethal dangers resulting from the vehicle during the procedure.
  • There are potentially lethal dangers resulting from component failures which would ordinarily be checked during routine servicing.
  • There is the potential for expensive vehicle damage from improper servicing procedures.

If you undertake your own servicing, you do so entirely at your own risk.

Parts and Equipment required (Click links below to find the items on eBay)

  • A large drain pan. eg:  15L or 17L
  • 10, 12mm and 14mm sockets
  • 10, 12 and 14mm spanners.
  • torque wrench

Coolant Options

Toyota genuine SLLC:  I'm using genuine Toyota Super Long Life Coolant (SLLC). It should be changed at 160,000km, then every 80,000km after that. It comes pre-mixed and you'll need 3x5L containers for the 200.

Penrite OEM 8-year premix:  This coolant meets Toyota's standards for long life replacement. You'll need 3x 5-litre containers for the 200.

Nulon HDDC:  This one is a concentrate that meets Toyota's standards for the 200. It needs to be mixed 1:1 with water. You'll need 2x5-litre containers for the 200.

Penrite OEM 8-year concentrate:  This is the same as the premixed Penrite coolant, but in concentrate form which should be mixed at 1:1 with water before use. You'll need 1x 5-litre and 1x 2.5-litre containers for the 200.

LandCruiser 200 Coolant Change

Step 1: Preparation

  • Ensure the engine is cold and the vehicle is parked on a level surface;
  • Remove the plastic trim panel from above the radiator;
  • Remove the plastic trim from the intercooler;
  • Remove the bash plates/covers under the engine.

If you have the standard cover plate, then these are the bolts to remove:

Step 2: Drain the coolant

  • Remove the radiator cap from the reservoir tank;
  • Place a drain pan (min 10L capacity) under the "radiator drain valve" and loosen the valve;
  • Allow the radiator to drain until the flow stops, then close the valve;
  • Place a drain pan under the "oil filter bracket drain valve" and loosen the valve;
  • Allow the engine to drain until the flow stops, then tighten the valve to 13Nm.

Step 3: Refill the coolant

  • Remove the engine air bleed cap and attach a clear hose to the pipe;
  • Using a 3/8" drive ratchet, remove the radiator vent plug;
  • Fill the reservoir tank with coolant until it reaches the filler neck. Note: Filling will be a slow process as the level approaches the top of the reservoir. You may have to leave it for a few minutes and gradually continue to top up the tank several times. 
  • As the coolant level nears the top of the reservoir, occasionally squeeze the top radiator hose to help remove air bubbles from the system;
  • Once coolant emerges from the engine bleed valve (into the clear tube), remove the tube and replace the engine air bleed cap;
  • Replace the radiator vent plug. Torque this to only 2Nm. Warning: Over-tightening this plug will cause it to break, If this happens, they are quite cheap and available online.
  • Replace the radiator reservoir cap.
  • Start the engine and let it idle for a few minutes. Wearing a glove, and avoiding the engine fan and belt, squeeze the top radiator hose repeatedly to bleed air from the system;
  • If the coolant level in the reservoir drops substantially, turn off the engine, allow it to cool, then top it back up to the filler neck, then start the engine again.

At this point, you need to bring the engine up to full operating temperature. Toyota suggest running the engine at 3000rpm for 10 minutes with the vehicle stationary. Personally, I decided to go for a short drive instead, returning once the Ultragauge showed ~80ºC.

  • Stop the engine and allow the coolant to cool back to ambient temperature. The coolant level in the reservoir should fall. Ensure the level sits between the low and full lines. Top up or drain the coolant as required.

Step 4: Completion

  • Check for any coolant leaks;
  • Refit the intercooler trim;
  • Refit the radiator trim with the 7 clips;
  • If you break or lose any of the trim clips, you can find the correct ones on eBay or Amazon.
  • Refit the bash plates, and bullbar trim panel (if fitted). Refitting is the reverse of the removal procedure. I suggest using a low-mid strength thread locking fluid (eg Loctite 222 or 243) on all bash plate bolts. Don't use high strength/stud lock, as the bolts need to be removed every 10,000km to change the oil and filter.

Thermostat and Coolant Replacement

Step 1: Preparation

  • Ensure the engine is cold and the vehicle is parked on a level surface;
  • Remove the plastic trim panel from above the radiator;
  • Remove intercooler trim cover;
  • Remove the MAF sensor plug, airbox lid and ducting;
  • Remove the Intake air connector;
  • Remove the bash plates/covers under the engine.

If you have the standard cover plate, then these are the bolts to remove:

Step 2: Drain the coolant

  • Remove the radiator cap from the reservoir tank;
  • Place a drain pan (min 10L capacity) under the radiator drain valve and loosen the valve;
  • Allow the radiator to drain until the flow stops, then close the valve;
  • Place a drain pan under the "oil filter bracket drain valve" and loosen the valve;
  • Allow the engine to drain until the flow stops, then tighten the valve to 13Nm.

Step 3: Replace the thermostat

  • Remove the two bolts securing the water inlet pipe to the front of the engine;
  • Remove the two bolts securing the water inlet pipe to the thermostat housing;
  • Carefully pull the top of the pipe away from the thermostat housing, and remove the thermostat and seal;
  • Install the new thermostat and seal, ensuring the seal is located correctly and the 'jiggle' valve is facing upwards.
  • Loosely reinstall the four bolts retaining the water inlet pipe. Then torque the bolts to 25Nm (front of engine) and 21Nm (thermostat housing).

Step 4: Refit air inlet systems

  • Refit the Intake air connector;
  • Refit the MAF sensor plug, airbox lid and ducting.

Step 5: Refill the coolant

  • Remove the engine air bleed cap and attach a clear hose to the pipe;
  • Using a 3/8" drive ratchet, remove the radiator vent plug;
  • Fill the reservoir tank with coolant until it reaches the filler neck. Note: Filling will be a slow process as the level approaches the top of the reservoir. You may have to leave it for a few minutes and gradually continue to top up the tank several times. 
  • As the coolant level nears the top of the reservoir, occasionally squeeze the top radiator hose to help remove air bubbles from the system;
  • Once coolant emerges from the engine bleed valve (into the clear tube), remove the tube and replace the engine air bleed cap;
  • Replace the radiator vent plug. Torque this to only 2Nm. Warning: Over-tightening this plug will cause it to break, If this happens, they are quite cheap and available online.
  • Replace the radiator reservoir cap.
  • Start the engine and let it idle for a few minutes. Wearing a glove, and avoiding the engine fan and belt, squeeze the top radiator hose repeatedly to bleed air from the system;
  • If the coolant level drops in the reservoir, turn off the engine, allow it to cool, then top it back up to the filler neck, then start the engine again.

At this point, you need to bring the engine up to full operating temperature. Toyota suggest running the engine at 3000rpm for 10 minutes with the vehicle stationary. Personally, I decided to go for a short drive instead, returning once the Ultragauge showed ~80ºC.

  • Stop the engine and allow the coolant to cool back to ambient temperature. The coolant level in the reservoir should fall. Ensure the level sits between the low and full lines. Top up or drain the coolant as required.

Step 6: Completion

  • Check for any coolant leaks;
  • Refit the intercooler trim;
  • Refit the radiator trim with the 7 clips;
  • If you break or lose any of the trim clips, you can find the correct ones on eBay or Amazon.
  • Refit the bash plates, and bullbar trim panel (if fitted). Refitting is the reverse of the removal procedure. I suggest using a low-mid strength thread locking fluid (eg Loctite 222 or 243) on all bash plate bolts. Don't use high strength/stud lock, as the bolts need to be removed every 10,000km to change the oil and filter.

Testing the old thermostat and Conclusion

After I swapped it out, I tested the old thermostat by putting it in a saucepan and slowly heating it along with a temperature probe, to check its operation.

Toyota specify it should begin to open at between 76ºC and 78ºC, and should be fully open (10mm) by 90ºC. In testing, mine began opening at 80ºC and was open 10mm by around 92ºC. So slightly out of spec.

After replacing the coolant and thermostat, I monitored the coolant temperature over the next couple of months driving. Average coolant temperatures dropped by 5-10ºC, constantly sitting between 76ºC and 85ºC. The highest I have seen since the change is 90ºC. So while the thermostat was out of spec by perhaps 2ºC, that doesn't explain the significant drop in coolant temperatures. It seems likely that replacing the coolant itself is responsible for a significant decline in engine temperatures.

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