Jetta cooling system discussions talk about opening the radiator cap. My Jetta doesn't have a radiaator cap. It does have a "globular" plastic unit with a black cap. I want to add Barrs Leak to seal the head gasket but hesitate adding it into that plastic unit since it doesn't appear to go directly to the cooling system. Any suggestions?

It doesn't go in the radiator. It goes in the round clear coolant reservoir. Open hood and it should be on driver's side near windshield. It's smaller than a basketball, and bigger than a softball. White (yellowed) plastic with a round black cap.

It doesn't go in the radiator. It goes in the round clear coolant reservoir. Open hood and it should be on driver's side near windshield. It's smaller than a basketball, and bigger than a softball. White (yellowed) plastic with a round black cap.

Did you install the thermostat backwards? It could be air bound.jack the car up on the side the radiator cap is on and run it to try to purg out air.your new thermostat could be bad. Remove it completely and see what happens.as for fan not working check connections and relay.if it has air conditioning that works turn it on and the fans should come on.if not there is either no power or bad fan motor.check with a test light for power at fan motor connection.

There Must Be Any Bleeding Screw On Any Hose Of Coolant, After adding Coolant Keep Open that Bleeding Screw For A 15min With Idle Speed It Will Help To Remove Air From Cooling system., Then Check Temp Sensor OF Radiator That May Got Problem , Only Tow Things Could Be The Problem. Thanks

its usually a plastic white/clear gallon on the side of the motor it will say coolant on the top do not fill or open any tops while car is hot extremely dangerous to do,wait till car cools open the top of the radiator even its the chrome top at the very front of the car under the hood fill to the top then find ur resevoir tank the liquid should be green its the only one with green liquid the cap will be labeled it just snaps on.good luck

sounds like your water pump is air bound ( there is a air bubble in your cooling system,or your water pump isn't turning.Bleed the cooling system by jacking car upso the antifreeze fill area is the highest point and run the engineat 1500 rpms add water if it goes down that tell you that the water pump is pulling.Also see if you have a air bleed on the cooling system.Keep the rpms up until you can't add anymore water then put cap back on before returning the engine to normal idle speed.

Assuming you have already filled your cooling system with the proper G12 coolant to the cross-hatch level, open the coolant overflow/fill bottle cap. Leave it off. Start the car and let it idle. Turn your heater on full hot and full fan speed. Let it come up to temp so the thermostat opens up and allows coolant to flow through your system. When the system burps, you'll see air bubbles show up in the overflow tank. Let it cycle a another time and then top off the coolant if needed. Then close up the cap and call it a day.

Cooling System
Ensure that the engine is completely cool prior to starting this service.
1. Remove the recovery tank or radiator cap.
2. Raise and support the vehicle.
3. Place a drain pan of sufficient capacity under the radiator and open the petcock (drain) on the radiator.
è Plastic petcocks easily bind. Before opening a plastic radiator petcock, spray it with some penetrating lubricant.
4. Drain the cooling system completely.
5. Close the petcock.
6. Remove the drain pan.
7. Lower the vehicle.
8. Determine the capacity of the cooling system, then property refill the system with a 50/50 mixture of fresh coolant and distilled water.
9. Leave the recovery tank or radiator cap off to aid in bleeding the system.
10. Start the engine and allow it to idle until the thermostat opens (the upper radiator hose will become hot). The coolant level should go down, this is normal as the system bleeds the air pockets out of the system.
11. Refill the system with coolant to the proper level.
12. Turn the engine OFF and check for leaks.

change the thermostate and gasket after you change it let the truck heat up then cool then refill the radiator again after the thermostate opens do not open the radiaator with the truck hot or the upper hose hard