Volkswagen Golf/Jetta/Cabriole 1990-1999

Cooling System

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FLUID RECOMMENDATIONS



All Volkswagens are filled with a mixture of water and special phosphate-free antifreeze/coolant at the factory. This antifreeze/coolant has corrosion inhibitors that prevent frost, the formation of chalk and also raise the boiling point of the water. Later models (up to 1996) are filled at the factory with a special antifreeze/coolant, known as G11. From 1996 through 1999, a new type of antifreeze/coolant was used in all models, known as G12.


NOTE
Standard antifreeze/coolant is bright green in color. The Volkswagen G11 coolant is blue, and the Volkswagen G12 coolant is pink. It is VERY important to identify which type of antifreeze/coolant your vehicle uses if you intend adjust the level or replace it completely. The different types of coolant CANNOT be mixed together.

LEVEL CHECK





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Fig. Coolant level marks on the expansion tank



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Fig. Unscrew the coolant reservoir cap to add fluid



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Fig. Add only the antifreeze that meets VW specifications



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Fig. Caution, it is easy to damage the plastic threads on the cap when installing it. If the cap does not feel like it is properly engaged with the threads, remove it and try threading it on the expansion tank again. DO NOT FORCE IT!

The coolant reservoir/expansion tank is translucent and if the reservoir is clean, it can be checked without removing the cap. The reservoir has LOW and HIGH level marks. The coolant must be between the two marks when the engine is cold, and slightly above the high mark at normal operating temperature. When removing the threaded pressure cap from the reservoir, loosen the cap slightly first. If the coolant begins to boil, tighten the cap again and wait for the engine to cool down.


CAUTION
Never open, service or drain the cooling system when hot; serious burns can occur from the steam and hot coolant.

Some models are equipped with a coolant warning light on the dash that flashes until the coolant is filled to the normal level. Although this can be considered a convenience item, periodic inspection of the coolant level in the reservoir itself is highly recommended.

If the coolant level is mildly low, it can be adjusted to the proper level by adding distilled water until the coolant reaches the MAX mark on the reservoir. If the coolant level is extremely low, it is recommended that a 50 / 50 mixture of coolant (make sure to use the same type of coolant that is in the vehicle) and distilled water be used to adjust the level in the reservoir. In extremely cold climates, a ratio of 60 percent antifreeze/coolant and 40 percent distilled water can be used to prevent freezing.

In large quantities, simply adding distilled water to the system can dilute the ratio of coolant and water, which reduces the cooling capabilities of the system, and in extreme cases, can cause freezing of the coolant if the vehicle is exposed to low temperatures. If the coolant freezes in the engine, the engine block can (and often times does) crack. To prevent the coolant mixture from freezing, avoid adding large quantities of distilled water to the system if it is low.

Drain & refill



All 4-Cylinder Engines


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Fig. Removing the thermostat from the bottom of the water pump



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Fig. View of the thermostat in the housing

On 4-cylinder engines, the most thorough way to drain the coolant from the engine is by removing the thermostat. The thermostat on all 4-cylinder engines is located at the bottom of the water pump housing. The lower radiator hose attaches directly to the thermostat cover/elbow.


CAUTION
Never attempt to drain the coolant from a hot engine. This is a messy job and there is no way to drain the coolant without getting it on your hands. Make sure the engine is thoroughly cooled before performing this procedure.

  1. Before raising the front of the vehicle, place the temperature control knob/slider to its warmest setting.
  2.  
  3. Raise and safely support the front of the vehicle on jackstands.
  4.  
  5. Some vehicles have a splash shield underneath the vehicle that may obstruct access to the thermostat cover/elbow. Remove the shield if necessary.
  6.  
  7. Place a large drain pan (large enough to contain the entire cooling system contents) under the water pump. Make sure the drain pan is clean, since the coolant should be reused unless it is dirty, or it does not pass a hydrometer test.
  8.  
  9. Using a 10mm socket and ratchet, loosen (but do not remove) the thermostat cover/elbow bolts. Coolant will start to flow from the elbow, so make sure the drain pan is positioned properly.
  10.  
  11. When the coolant stops flowing, remove the thermostat cover/elbow bolts, and set the cover/elbow aside. It's not necessary to disconnect the lower radiator hose. When removing the cover/elbow bolts, hold the cover/elbow in place; then, slowly lower the cover/elbow and hose. The thermostat may stick in place; be careful when removing it, as residual coolant may still be in the engine.
  12.  
  13. Once the thermostat is remove, remove the coolant reservoir cap to drain the rest of the coolant.
  14.  

To install:

  1. Clean and dry the thermostat housing and the rubber O-ring. Examine the O-ring for cracks or damage and replace as necessary.
  2.  
  3. Install the thermostat into the water pump housing on the engine, then fit the O-ring into place.
  4.  
  5. Install the thermostat housing and tighten the bolts evenly. Torque the bolts to 87 inch lbs. (10 Nm). Do not over torque these bolts or the housing may break.
  6.  
  7. If equipped, install the splash shield.
  8.  
  9. Lower the vehicle from the jackstands. Make sure the car is level.
  10.  
  11. Loosen the upper radiator hose and begin filling the system (with the proper mixture of coolant and distilled water) through the coolant reservoir. Loosening the upper hose will allow the air to escape and speed the process.
  12.  
  13. When the system will not take any more coolant, tighten the hose and start the engine. Watch for leaks, and add more coolant as required. Don't run the engine too long with the reservoir cap removed or it will boil over.
  14.  

VR6 Engines Only

On VR6 engines, a drain plug is installed in the coolant pipe, which runs between the coolant pump and the thermostat housing.

  1. Before raising the front of the vehicle, place the temperature control knob/slider to its warmest setting.
  2.  
  3. Raise and safely support the front of the vehicle on jackstands.
  4.  
  5. Some vehicles have a splash shield underneath the vehicle that may obstruct access to the coolant pipe. Remove the shield if necessary to allow adequate access to the coolant pipe.
  6.  
  7. Place a large drain pan (large enough to contain the entire cooling system contents) under the drain plug. Make sure the drain pan is clean, since the coolant should be reused unless it is dirty, or it does not pass a hydrometer test.
  8.  
  9. Loosen (but do not remove) the coolant drain plug. Push against the drain plug while unscrewing it by hand. When the drain plug is free of the threads, quickly remove it from the coolant pipe, and allow the coolant to drain from the vehicle.
  10.  
  11. While the coolant is draining, remove the coolant reservoir cap; this will allow thorough draining of the system.
  12.  

To install:

  1. Using a new O-ring on the drain plug, install the drain plug into the coolant pipe. Tighten the drain plug to 89 inch lbs. (10 Nm).
  2.  
  3. If equipped, install the splash shield.
  4.  
  5. Lower the vehicle from the jackstands. Make sure the car is level.
  6.  
  7. Using either the drained coolant, or a fresh mixture of the proper type of coolant and distilled water, slowly fill the cooling system through the coolant reservoir. If possible, loosen the upper hose; this will allow the air to escape and speed the process.
  8.  
  9. When the system will not take any more coolant, tighten the hose (if loosened) and start the engine. Watch for leaks, and add more coolant as required. Don't run the engine too long with the reservoir cap removed or it will boil over.
  10.  

flushing and cleaning the system



On older vehicles equipped with standard coolant/antifreeze, the cooling system should be drained and refilled with new coolant at least every 30,000 miles or 24 months. If desired, a flush system designed specifically for aluminum cooling components should be used. Follow the instructions on the package.

On vehicles with G11 and G12 coolant/antifreeze, (blue and pink, respectively). Both G11 and G12 coolant is considered a "lifetime" coolant, the manufacturer does not recommend any special cooling system flushing or replacement.

 
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