I know nothing about VDUB codes, sorry

 

I just replaced the coolant temp sensor (green). Same issues

 

Today, I visited this forum so I found that it's very interested for me.. there are many topics available here so I like this so much.....
I hope that you will read care fully and tell me more benifits about this .........

 

So I replaced the cooland temp sensor and the thermostat. Still having the same issues with over heating when I rev the car in the driveway after it warms up. And now after I replaced the thermostat and refilled the anti-freeze, the car had white smoke from the exhaust....

 

I found this on another forum. Sounds like your problem:

"The first thing I replaced was the engine coolant temp sensor (black replaced with green). This solved the problem for a couple of weeks, then threw a code. I replaced the ect sensor again since it was so cheap and easy...

I then replaced the thermostat. The spring in the OEM thermostat seemed weak, so I thought it might be opening too soon and I had found the problem. WRONG! Two days after the new thermostat, another CEL.

I am disconnecting the battery to clear the CEL each time. The blue water temp light always goes out after a few minutes of driving. My wife says the CEL usually comes on in the morning as she accelerates up to speed on the interstate.

The guys over at the Audi A4 forum have a TSB from Audi that their problem is an auxillary radiator hose that has a faulty check (non-return) valve. They have a hose from the radiator to what they call an auxillary radiator. The check valve stays open preventing the coolant from reaching operating temperature which throws the CEL code 2181."

As for the white smoke from your exhaust it could be a number of things.
1. Burning antifreeze. Would have a sweetish smell and the smoke dissipates in the air quickly.
2. Transmission fluid, which would be a very dense cloud of smoke. This from a faulty valve, etc.
3. Oil, but that would be a whitish-blue and would smell like burning oil.

Since you just changed your coolant sensor and the coolant, I'm guessing it's coolant. Make sure all seals are good and coolant isn't migrating anywhere. Also, that your coolant level is within max/min levels. Also (and I'm just asking to put on the check list) did you use the proper G12 coolant that VW requires?

 

Just adding this if anyone could use it:

How To Change Engine Coolant On A Vw 4 Cylinder (1998 - On) :

When the engine has cooled down, remove the Vw coolant tank cap.
Draining the Vw coolant from the 4cyl cooling system:
Remove the lower radiator drain plug from the lower front of the radiator (Vw A4, Vw Passat). Remove the passenger side lower radiator hose. Remove the outer Vw coolant hose that connects to the oil cooler. To drain the heater core you'll need to remove the hose on the coolant flange or transfer pipe located on the back side of the engine. This hose goes from the cylinder head to the heater core.
After the system is done draining, put the Vw coolant tank cap back on. Carefully work off and remove the smallest hose that is connected to the top of the Vw coolant tank. Be careful, the tank nipple likes to crack and break off.
With a blow gun and compressed air on low, carefully insert the blow nozzle into the small hose. Wearing safety goggles, carefully force the air out so that any Vw coolant that's still trapped in the cooling system is released.
Reinstall the Vw coolant drain plug. Reinstall the coolant tank hose(s). Fill the Vw cooling system with distilled water. Start the car and air bleed the cooling system as outlined in the factory Bentley manual. Run the car until the cooling fan comes on.
Repeat steps 1 through 5 until the water comes out clean.
Verify that you have the correct anti-phospate anti-amine G11 or G12 Vw coolant. If it's full concentrate, mix a 50/50 ratio per the Bentley manual. Fill your Vw cooling system with this 50/50 mixture. Note: Some factory Vw coolants sold by dealers are already premixed and do not require further delusion.
Run the 4cyl engine and check for any Vw coolant leaks.
Top off the coolant tank to the fill line. Do not overfill.
Using a permanent marker, write 'G11 or G12 Coolant Only' on the Vw coolant tank.
Be environmentally responsible and dispose of your old Vw coolant properly.
Vw Coolant System Maintenance:

Never top off the coolant tank with full concentrate G11 or G12 Vw coolant. Your Vw coolant should never exceed a coolant ratio of 80%. If it's over 80% an inefficient Vw cooling system will result, decreasing flow through the radiator along with poor heat transfer through the engine block.
Always top off your Vw coolant tank using a 50/50 mixture. If you're in a pinch and don't have any, use a small amount of distilled water. Remember, adding large amounts of water will change the alkalinity of the Vw coolant and throw off the glycol to water ratio, making it less effective in cold temperatures.
Never mix G11 blue coolant and G12 red coolant. It will turn into a brownish goo and plug up your Vw cooling system.
We highly recommend flushing your Vw's coolant when replacing your timing belt.

 

I did not use proper VW coolant because the 3 parts stores in my area were all sold out, so I just used water to refill and test it. I also forgot to mention that I pulled the code of P0116

 

Yikes! Well, I guess adding a little water (though not recommended) is better than using completely improper coolant. Ahh, errr...I might suggest a complete flush and use the proper pink stuff. If your store doesn't have it, then just get it from the dealer. I know that Pep Boys usually has it if there's one near you.

As for your new code P0116, I found this on a very old thread on this site:

"It's the Engine Coolant Temperature circuit. It's located in the coolant pipe near the coolant outlet. Check the terminals in the connector and the wires leading to the sensor for looseness and breaks."

 

U need to replace the water pump. VW uses a plastic impeller. What has happen is that the impeller has broken off the gear. So at high speeds it slips and doesnt spin. I had the same problem and found out the hard way by doing the same stuff ur doing. Finally i changed the water pump and couldnt believe it when i seen the plastic impeller broken. Unbelievable VW!!!