Touareg: 2012 V6 FSI
Join Date: Feb 2017
Location: West Virginia, US
Second Vehicle: Other
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2012 Touareg 3.6L intermittent overheat
I have done my best to search clubtouareg, vwvortex, and google and have come up short on finding much on the newer models with regard to overheating. Created an account to post this question. Thanks for any help you can offer.
2012 Touareg Lux V6 3.6L 80k miles
The Treg will sometimes overheat about 10 mins after cold start. Temp gauge goes into the red (260F +) with a warning on the dash to check coolant level. When this happens, pull to the side of the road and it cools off quickly (like 2-3 mins). After it cools back to the nominal 200F on the dash, it doesn't overheat for the rest of the trip.
I have VCDS and pulled one code: P2181 performance malfunction in cooling system and the freeze frame data shows a coolant temp of 72C (normal). I just replaced the thermostat three days ago. The old one was broken and I thought I had the problem licked. It drove fine for 2 days but them the issue returned on the next two days. When it overheats, I turn the inside heater on HI and noticed that for a brief moment that cool air came out but then was hot again (happened twice). This leads me to believe I have air in the system. The coolant level is fine. I have been watching it to see if it falls much (meaning air was escaping) but I haven't seen an appreciable difference.
- 40k miles, carfax indicates that the thermostat and water pump was replaced
- 43k miles, carfax indicates that the termostat and water pump was replaced again as well as the thermostat housing and coolant temperature sensor.
- 80k miles I replaced thermostat and drained coolant, replaced with G13 coolant
- Thermostat: Symptoms still sound like a sticking thermostat. Could have gotten a bad thermostat.
- Air in the system: The fact that cool air came out a little bit with interior heater on really sounds like air in the system but the system should be self bleed. Maybe I have a plugged return line or something. I plan to remove the little line on the top of the expansion tank to ensure a stream of coolant is coming through when the system is at temperature
- Sensor: Seems like the older touaregs have 2 sensors. I can only find 1 sensor on the parts diagrams but VCDS does offer 2 readings (can someone confirm if mine has 2 sensors? I see the one at the rear driver's side of the engine) . Maybe the sensor is bad but the system isn't even overheating. The dash does not appear to act like a bad sensor... the needle moves smoothly and doesn't jump around.
- Electric Fan: Nope, I have confirmed the fan is off when cold and on when hot.
- Head gasket: Please no... I am close to spending $40 to get the exhaust gas leak tester thing just to cross this off.
Thoughts?? Thanks in advance.