Thermostat broken

[jursch2211]

Anyone know how bad it is driving on a bad thermostat? I noticed that I had been driving around for about an hour yesterday and when I looked I noticed the needle was half way between cold and normal. Am I doing any damage driving like this?

[AudiA4_20T]

could be your coolant temp sensor, our thermostats dont really go bad ever

[CO AVANT]

Mine did, well sort of. It wasn't the thermo failing itself but the electrical connector on it. Even threw fault codes for it (no signal). When I took my old one off to replace it the electrical connection at the thermostat literally fell off to the ground. The connector at the thermostat was only getting a connection before because it was still sitting in place by the wire connection connecting to it. Never dropped or damaged it in any way so was kind of pissed that the electrical connector just fell off...

[Nikon44]

Same thing happened to me this weekend changing my timing belt. I had to pull the thermostat to replace the plug behind it because it was leaking. I started disconnecting hoses, went to pull the sensor and it just fell right off. It was broke and one half stuck in the housing. Luckily I had a spare thermostat lying around.

Sean

[jursch2211]

Well I ordered a new part and plan to get it in before the weekend trip. I keep getting the same fault code open circuit and no response. I already replace the coolant temp sensor, MAF, Bank 1 O2 sensor, and other various related and maybe non-related issues. I just want to make sure that if I drive on it before I get it fixed this Friday, if I will be doing permanent damage.

[CO AVANT]

Well I ordered a new part and plan to get it in before the weekend trip. I keep getting the same fault code open circuit and no response. I already replace the coolant temp sensor, MAF, Bank 1 O2 sensor, and other various related and maybe non-related issues. I just want to make sure that if I drive on it before I get it fixed this Friday, if I will be doing permanent damage.

that is the fault code I was getting in regards to what I posted above ^^^

[jursch2211]

Oh ok well i ordered the part so I might as well replace it. Thanks for the help thought. Probably overkill but at least I can get under the car and see if I see anything else wrong. Hopefully not.

[AudiHere04]

my coolant temp sensor works when it wants to....lol
Some days the needle doesnt move, then 30 mins later the needle will jump to mid, 3 mins later back to cold...i need to replace mine

[Matt Devo]

our thermostats don't really go bad ever

while not as frequent as CTS failures, our thermostats do occasionally fail as well. Mine went around 100k. I even did a write up in the Tech Articles

[Audi Skate Snow]

if it did by some chance fail then your car would run cold

[jursch2211]

^ That is exactly what my car is doing. The needle is off to the cold side. It's not all the way down, but a little above the C.

[Audi Skate Snow]

Yea if it is a faulty thermostat then your car will run cold for long periods of time.

[doublezero30]

next time youre out driving over a period of time where it would normally be warmed up, turn on the heat. if you are getting heat out of the vents chances are it is not the thermostat and i would be willing to bet it was the coolant temp sensor. i just went through this diagnosis and that i what a guy at my dealership told me. i had heat through the vents so changed the sensor($25), and everything is good again.

[Audi Skate Snow]

could be a number of things... shitty part is your car probably feels like dog shit becuase if the car is reading cool temps, then its prolly staying in open loop which is a rich condition :(