Second thermostat sticking open? New working thermostat part , fix? Any info

[mrb5_supra_wrx]

So guys got my car and not too long after getting it noticed my temp gauge was staying cold. So I got a new OEM thermostat replacement kit and water pump off ECS and replaced it. Car drove fine for about a week then the temp began sticking on the cold line again. Cleared the temp code and car drove as normal for the last almost 2 months. Then all of. Sudden today on the way home the cooling malfunction code came back on and temp was staying on cold line untill I got in it a bit then jumped up to about almost normal op temps but starting goin back down . Needless to say I'm ready to rule out the bad thermostats. Has there been an updated part number with proper working thermostats. I've heard thermostats are a common issue for b8 cars but there has to be a fix for this any info?

[Dr GP]

Usually when people report a thermostat failure it is stuck in the closed position causing overheating. BTW, do you have the oil temp gage activated. Also, how soon does it take for the heater to make warm air? In my S4s , the cars have made warm air VERY quickly , indicating a closed thermostat at start.

[mrb5_supra_wrx]

Usually when people report a thermostat failure it is stuck in the closed position causing overheating. BTW, do you have the oil temp gage activated. Also, how soon does it take for the heater to make warm air? In my S4s , the cars have made warm air VERY quickly , indicating a closed thermostat at start.
Oil temp gauge activated? And when the temps are normal and it's not sticking it's within a few mins for the air to get warm it's almost instant. But when it's sticking cold it doesn't warm up untill like I said earlier if I get in it a lil bit then the temps move toward normal and then start to warm up. I thought maybe it was my coolant temperature sensor but with the heater not working unless temps catch up then I figure it is the thermostat

[chi123]

Replace your coolant temperature sensor. My thermostat went bad and broke apart so I replaced it. Worked fine for a while but then it would not reach operating temp or the needle would move around on random occasions. Thought I got a faulty thermostat so I replaced it again and did the same thing. Decided to replace the coolant temperature sensor and now I haven't had any issues. The part was like $12 on ECS for an aftermarket one or like $60 for OEM. Aftermarket one looked identical to the faulty OEM one. Install was only 15 minutes. You just reach in under the SC pulley and you'll see it there. Unplug the connector, pull out retaining clip, and sensor comes out.

[mrb5_supra_wrx]

Replace your coolant temperature sensor. My thermostat went bad and broke apart so I replaced it. Worked fine for a while but then it would not reach operating temp or the needle would move around on random occasions. Thought I got a faulty thermostat so I replaced it again and did the same thing. Decided to replace the coolant temperature sensor and now I haven't had any issues. The part was like $12 on ECS for an aftermarket one or like $60 for OEM. Aftermarket one looked identical to the faulty OEM one. Install was only 15 minutes. You just reach in under the SC pulley and you'll see it there. Unplug the connector, pull out retaining clip, and sensor comes out. yes that was my step by I've been looking everywhere for the location of the CTS. Appreciate brother yes IL prob try to just change it out tmrw . But how'd you find out where it was? I couldn't find anything on all data, the forums, etc.

[EHesh14]

The same exact scenario happened with me. I thought I was the only one with a stuck open thermostat. Had it replaced a few months ago and the temp was acting up again....it ended up being a faulty temp sensor.

[mdmay]

Guys is there a diagram for where the coolant temperature sensor is

Sent from my ONE A2003 using Tapatalk

[14S4GWM]

Guys is there a diagram for where the coolant temperature sensor is

Sent from my ONE A2003 using Tapatalk

All I got buddy

http://i55.photobucket.com/albums/g126/krothrock1/Audi%20S4/Screen%20Shot%202017-01-02%20at%2012.21.31%20PM.png

http://i55.photobucket.com/albums/g126/krothrock1/Audi%20S4/Screen%20Shot%202017-01-02%20at%2012.25.51%20PM.png
#3 in this one

[mdmay]

Cheers. I have exactly the same symptoms as you and this would be an easier fix than the thermostat

Sent from my ONE A2003 using Tapatalk

[Dr GP]

Oil temp gauge activated?
I assumed you knew that the oil temp gage can be activated with a vag com.

[mrb5_supra_wrx]

I assumed you knew that the oil temp gage can be activated with a vag com. i actually didn't know still need to get another vagcom . Haven't had one since I sold my b5.

[mrb5_supra_wrx]

And ordered a new CTS from ECS but they don't open back up till tmrw so I guess gota wait the rest of the week to get it :(

[mmm def]

Same thing happened to mine was the cts. Here's what mine was doing. https://youtu.be/frAUMnban1c

[blackjak]

The therm housing in these cars are pretty crappy design. I do believe there is an aftermarket replacement that is an all aluminum housing, I've gone through 2 plastic OEM ones. Just a thought when and if anyone needs to replace there housing.

[S4'ed]

There is no all-aluminum aftermarket thermostat housing for this engine.

[mrb5_supra_wrx]

So after driving the car again and that's actually pretty cold outside so I try to run the Heat and it barely blows hot. So now I'm still the question if the thermostat and it stuck open actually and it's not the CTS. HVAC system won't not blow hot from the CTS be bad will it ? I just noticed I had a 00447 code as well

[EHesh14]

Seems to be the therm sticking open. Had this same issue a while ago.

[jygesq]

Seems to be the therm sticking open. Had this same issue a while ago. better open than closed: no heat Vs overheat.

[mrb5_supra_wrx]

What I don't understand is how could a new OEM thermostat go bad in less than a week doesn't make any sense

[mrb5_supra_wrx]

And it's weird for two thermostats to be stuck open back to back. I should have my CTS tmrw and il put that in and see what happens but for me to have no heat would think for it to be the thermostat

[mrb5_supra_wrx]

Bump? Anyone with further insight on a working thermostat or any issues the coolant temp sensor causing similar issues

[mrb5_supra_wrx]

So I'm getting a p3081 engine temperature too low cold.. could that be from my CTS?

[mrb5_supra_wrx]

So I'm bumping up this thread BC I've replaced my coolant temp sensor to no avail. Still trying to figure how a new OEM thermostat sticks open too . Tryin to not have to replace another thermostat if it could be any other options. Anyone have a clue what this could be?

[theweebabyseamus]

So I'm bumping up this thread BC I've replaced my coolant temp sensor to no avail. Still trying to figure how a new OEM thermostat sticks open too . Tryin to not have to replace another thermostat if it could be any other options. Anyone have a clue what this could be?

I just looked at Rock Auto and there are two temps from MOTORAD there. I suppose its possible that somehow we got 185 ones instead of the correct 192f...

[mkl101]

Hate to revive an old thread but my car is doing this exact thing