Engine Cool Off

**S4Mon** · 11-04-2022 04:51 PM

Is it normal for the 3.0T supercharger/engine surface temperatures to be around 188 F after the car has been sitting for 4 hours? I just checked the surface temps with a FLIR camera and was surprised to discover the aluminum engine was still this 🔥

It was sitting in the 211 F range about an hour after a 40 mile highway drive.

Hopefully others are like this and I can start sleeping at night!

**Nillious** · 11-04-2022 07:36 PM

Engines get hotter after you shut them off. If you shut an engine down at 210, not uncommon for it to climb to 230 or so before it starts to cool. Also if you were pointing it at the blower it gets VERY hot when parked after driving and will actually stay pretty cool during steady driving.

**S4Mon** · 11-05-2022 05:44 AM

Interesting. I figured since the combustion process is stopped it stays at whatever temp it's at and then gradually cools down from there.

**Nillious** · 11-05-2022 08:44 AM

I guess I shouldn’t say it gets hotter but the the coolant absorbs the heat and gets hotter cause it’s at a standstill in the motor. The lack of flow through the blower of coolant and air plus it absorbs the heat from the motor causes it to get hotter to touch as well. The actual block and heads will begin to cool immediately. If that makes sense.

**TC_S4** · 11-05-2022 09:49 AM

It’s totally normal. It’s actually a very good source of heating, for the last 10 years never opened heat in my garage at winter.

**S4Mon** · 11-05-2022 10:55 AM

So your superchargers stay scalding hot for over 4 hours after shutting down? Ambient garage temps are around 60 F. I guess I'm just worried because I replaced the water pump, thermostat and pcv recently maybe I didn't get all the air out of the system. But I don't see bubbles coming out of the supercharger bleed screws which is good. I also don't have a point of reference before I made the repairs. Never paid attention to it really.

**TC_S4** · 11-05-2022 03:31 PM

Originally Posted by S4Mon

So your superchargers stay scalding hot for over 4 hours after shutting down? Ambient garage temps are around 60 F. I guess I'm just worried because I replaced the water pump, thermostat and pcv recently maybe I didn't get all the air out of the system. But I don't see bubbles coming out of the supercharger bleed screws which is good. I also don't have a point of reference before I made the repairs. Never paid attention to it really.

The only proper way to see if your cooling system is healthy and free of bubbles is to monitor your IAT.

**S4Mon** · 11-05-2022 04:37 PM

Intake air temp? How do you do that?

**TC_S4** · 11-05-2022 05:37 PM

Originally Posted by S4Mon

Intake air temp? How do you do that?

Yes, Intake Air Temperature. You can get the expensive P3 gauges or you can simply get a bluetooth dongle with an app. I use OBDFusion, so I keep an eye on my coolant, SC intercoolers, cats and IAT.

Image1667695012.888059.jpg

**S4Mon** · 11-05-2022 07:19 PM

So is there a factory installed temp sensor in the throttle body that the app can read?

**TC_S4** · 11-05-2022 07:59 PM

Originally Posted by S4Mon

So is there a factory installed temp sensor in the throttle body that the app can read?

No, it’s not like the P3 that you plug a sensor in the throttle body and measure the actual IAT. The app is calculating the IAT, less precise but pretty close..

**RoofRails** · 11-06-2022 08:38 PM

Originally Posted by TC_S4

No, it’s not like the P3 that you plug a sensor in the throttle body and measure the actual IAT. The app is calculating the IAT, less precise but pretty close..

If that app is reading from the OBD 2 port then its getting its information from the same sensors that the P3 monitors. I have one called Torque pro and it reads from the OBD2 and polls the same sensors you would data log.

Sent from my SHT-W09 using Audizine mobile app

**TC_S4** · 11-07-2022 03:19 PM

Originally Posted by RoofRails

If that app is reading from the OBD 2 port then its getting its information from the same sensors that the P3 monitors. I have one called Torque pro and it reads from the OBD2 and polls the same sensors you would data log.

Sent from my SHT-W09 using Audizine mobile app

Yes, you’re right, for the IAT it reads from OBD2 so OBDFusion, Torque app and p3 have all the same reading from the same sensor. I mixed up with the boost reading for the P3, which it reads from the throttle body and App are calculated.

**S4Mon** · 11-10-2022 04:58 PM

I downloaded the torque pro app but it won't connect to my Carista OBD 2 adapter. Do I have to buy a new adapter?

**RoofRails** · 11-11-2022 03:41 AM

Originally Posted by S4Mon

I downloaded the torque pro app but it won't connect to my Carista OBD 2 adapter. Do I have to buy a new adapter?

I can't 100% answer the Carista question but if that is a dedicated dongle like OBD Eleven then your not going to be able to use it. I use OBDlink LX and it's been fantastic for a few years now. As always technology advances so do a little looking before you pull the trigger on this one.

OBDLink LX OBD2 Bluetooth Scanner for Android and Windows https://a.co/d/izVnUMh

Sent from my SM-S908U1 using Audizine Forum mobile app

**TC_S4** · 11-11-2022 07:57 PM

Originally Posted by S4Mon

I downloaded the torque pro app but it won't connect to my Carista OBD 2 adapter. Do I have to buy a new adapter?

Carista should work with Torque, it’s one of the Carista compatible app. I use Carista obd2 dongle to connect OBD FUSION and Dashcommand app with no issue.

https://caristaapp.com/supported-apps

**S4Mon** · 11-13-2022 11:54 AM

Yes your right about it being compatible. I guess I'm not sure how to connect Torque to the adapter. In Carista, you make sure the ignition is on, Bluetooth is on and tap connect on the app. I guess i need to look around in the Torque app more.

Do I click on my profile in the top right of the main screen in Torque?

**TC_S4** · 11-14-2022 05:20 PM

I never used Torque app since I am not an Android user. However, the app should have the Type of Communication, since you have a Carista adaptor, it should be set at Bluetooth LE (Low Energy). Then ignition On and tap connect.

**S4Mon** · 11-22-2022 11:28 AM

Ok i got it connected but need to figure out how to read intake temps. I don't think torque has this by default but apparently you can add equations manually?

**RoofRails** · 11-23-2022 04:31 AM

Originally Posted by S4Mon

Ok i got it connected but need to figure out how to read intake temps. I don't think torque has this by default but apparently you can add equations manually?

IAT is there as standard. I believe it's listed as Charge Temps. You can also check out this thread for adding the non-standard PIDS.

https://www.audizine.com/forum/showthread.php?t=920460

Sent from my SM-S908U1 using Audizine Forum mobile app

**S4Mon** · 11-23-2022 07:31 PM

Thank you! Actually I see "Charge Air Cooler Temp" and literally "Intake Air Temperature". I'll display both and compare the numbers.

What are typical intake air temps for stock S4s?

**Nillious** · 11-23-2022 09:23 PM

On my scanner I see intake air temperature and intake air temperature B1S1. My car is all stock. Driving in 40f weather one said 58 and the other was hovering around 90f. Under wot the first one would drop to 45 and other would climb to about 115. This was a second gear run uphill to top of fourth.

**S4Mon** · 11-30-2022 11:32 AM

Intake Air temperature gives no value but the Charge Air Cooler Temperature was averaging 80F with a low of 67F and a high of 100F. This was during a 37-mile commute with highway speeds of about 75mph and ambient temps of 50F. I noticed when I would WOT and gained speed the CACT temps would drop dramatically and then return to around 80F.

Does anyone know which sensor it is pulling data from?

**Fresh.S4** · 11-30-2022 12:17 PM

CACT

cruising = 20* above ambient
wide open = 60* climb above ambient

**TC_S4** · 11-30-2022 10:16 PM

Originally Posted by S4Mon

Intake Air temperature gives no value but the Charge Air Cooler Temperature was averaging 80F with a low of 67F and a high of 100F. This was during a 37-mile commute with highway speeds of about 75mph and ambient temps of 50F. I noticed when I would WOT and gained speed the CACT temps would drop dramatically and then return to around 80F.

Does anyone know which sensor it is pulling data from?

It’s either the charge air sensor on bank 1 or bank 2, on the side. If you look at my diagram setup, the IAT is the sensor in the middle on the throttle body, the charge air cooler bank 1(the passager side) and charge air cooler bank 2 (the driver side).

You’re measure the wrong sensor, the most important one is the one in the middle, on the throttle body.