Coolant temperature sensor 1

[Boostedawd91]

Currently getting multiple codes
Engine Coolant temperature sensor 1 high voltage
Engine coolant temperature sensor 1
Circuit range performance
Engine temperature to low

I'm assuming coolant temperature sensor 1 is on its way out. Car still runs and drives fine, but the high rpm "cold start" is gone. It starts up and stays at about 700-800. Idle is a little weird.
Obd11 still shows coolant temperature live fans work, and gauge in the cluster work still. If I clear the codes they don't come back until a few cold starts later, Cruising it's fine.
So where exactly is this sensor? I found a rough diagram showing it by the head ? I want to make sure before I swap sensors, as I seen there are a few actually.

[Boostedawd91]

Forgot to add, car is a 2016 s6 4.0t

[NorthernGTI]

Got this from alldata. Hope it helps.

Sent from my SM-S916W using Audizine Forum mobile app

[Boostedawd91]

Thank you, it gives me a general idea of where they are. I'm not sure which one is sensor 1, but I'm going to change the one the head and hope

[Botbasher]

Thank you, it gives me a general idea of where they are. I'm not sure which one is sensor 1, but I'm going to change the one the head and hope

If you aren't sure which one is bad, plan on doing both of the ones on the front of the motor at the same time, regardless. You have to get it in service position, to even SEE the sensor, much less touch it. The one on the t-stat housing is easy to get to by removing the liner and undertray.

20241109_181203.jpg

You are looking for those sensors located about 11 o'clock here from the crank pulley. UNDER the intake plenum! If you look WAY over about 3 o'clock, you can just see the hint of gold in the t-stat outlet for the radiator. That is your third sensor.

Good luck! I was just in there for leaks and WMI install. I hate squeezing and just pull the front off for anything on the front now!

Cheers,

KS

[Boostedawd91]

Tha know you for that, but Jesus, taking the front end off just to change a 30$ sensor? That's a bit ridiculous.
But I guess it need to be done

[Boostedawd91]

Thank*

[Botbasher]

Tha know you for that, but Jesus, taking the front end off just to change a 30$ sensor? That's a bit ridiculous.
But I guess it need to be done

You don't HAVE to take the front end off to access anything on the front of the motor. There is a half way point called Service Position that moves the radiator core out about 6" to allow "access" to the parts you need to get to. Just about everything on the front and even the top of the motor needs it though. Even the PCV requires it!

I prefer to go the extra 3 steps and pull the core support and have clear and unfettered access to everything. I can sit in front of it and work without jamming my big arms in tight places and without leaning over it. It only takes 10-15 minutes extra on the disassembly.

My bigger point to pulling the front off is being able to see EVERYTHING and address any future issues. It's nice to be able to see leaks, wear and things early and address them before they get nasty!!

To each their own... my way is easier on the arms and back for me!

Cheers,

KS

[Boostedawd91]

I haven't had the car for a year yet. I had the front bumper off for a heat X upgrade and rs grill swap, but haven't done the service position yet. I seen a few videos already and it doesn't seem like it's terribly hard. It's just going to be something new to me

Thank you for the input, I'll definitely keep an eye for other things while I'm there.

[Akakios]

I haven't had the car for a year yet. I had the front bumper off for a heat X upgrade and rs grill swap, but haven't done the service position yet. I seen a few videos already and it doesn't seem like it's terribly hard. It's just going to be something new to me

Thank you for the input, I'll definitely keep an eye for other things while I'm there.

You were almost there!

It's really just front bumper off, replace some bolts with longer bolts and remove a few bolts then slowly pull it back for service mode. If you want to take it one step further, you'll need to disconnect the radiator hose and fan connectors and pivot the whole front end to the side like Botbasher has in his pictures. The AC condensor can lay on a chair near the front area to keep it still full of freon and avoid draining it down to disconnect it.

https://www.youtube.com/shorts/xclTxaunDMo

Older video now, the music turned up for some reason and we can't edit stuff post submission.

[Boostedawd91]

Thank you. Hopefully should he straight forward

[Botbasher]

Thank you. Hopefully should he straight forward

The only thing that is really difficult can be finding bolts long enough to make it useful. The longer the better. I found some 120mm ones at a local fastener store. They have a spot in my tool box so they don't get lost or "repurposed".

Given that you already need to break open the coolant system, and if nothing else needs attention, basic service position will do all you need!

Cheers,

KS

P.S. Make sure you mark the position of the mounting tabs for your headlights and when you pull the bolts, and make sure the mounts, which are adjustable, don't self adjust. Otherwise you'll end up with headlights that look like Mater's cousin on Friday night!! Make a note of how many threads you see on them and then hold that silver plate with a finger or screwdriver while unscrewing them. Not exactly like this but you'll see...