I've had the same problem for a while now. Dash temperature and console temperature gauges not working at all on my 1995 Audi 90s Quattro, causing the car to still run rich and puff out very visibly white smoke when the engine has warmed up. I've now changed the smaller coolant temp sensor and the 3 prong MFTSensor with no success. Cleared codes, then checked them again. I'm still getting 2312: "Engine Coolant Temperature Sensor."
Now what? What are the likely problems? Definitely frustrating that $70 in sensors and a month of waiting for them to ship has left me at the same spot. Any help would be greatly appreciated. Thanks guys!
My first thoughts: Ugh, another sensor? ... Well anyways, what's this sensor called? I haven't looked under the hood yet to see which one you are talking about.
However, I did notice today when driving around the same amount as usual that the problem has gotten a LITTLE better. For the first time in many months I saw the dash engine temp gauge go to 1/4th heat and the oil temp gauge move enough so that it was no longer at bare minimum. It's a start! And I think it made the engine run a tiny bit less rich too, if I'm not imagining things.
I had the same problem, replaced the temp. sensor and the car would not warmed up to opp. temperature, did not have de code any more, but after I replaced the thermostat, it reaches operating temperature no problem.
Sid and Greg, thank you both! I have been driving a couple days now with both sensors replaced like I was talking about, and the check engine light doesn't pop on anymore on the highway and there is significantly less rich white exhaust.
Quick couple questions. Is the thermostat hard to get to? I haven't researched or looked very hard myself at this point, but I think I remember reading you have to take a belt off?
This site? I can't seem to find anything thermostat related other then briefly mentioning it.
However, I did read "The timing belt on the 12v engine can last 95,000 or more miles, in theory. In practice, however, the water pump (which is driven by the timing belt) starts to go bad at around 75,000 miles and could seize, which will cause the timing belt to snap very quickly. I recommend that you replace your timing belt, timing belt tensioner, water pump, and coolant thermostat every 60,000 miles."
Hmm, at this point, should I just fork over the cash and have the professionals be the ones to get greasy to get my 180,000 mile Audi back up to par? And now would be a good time to mention that my engine idle speed drops significantly when I try and turn the wheel a lot while it isn't moving. Isn't that timing belt related?
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