Can anyone help with a sensor location??
 

Hi,

I have a 2008 Q7 3.6 V6.

I need to locate one of the engine temp cooling sensors. I have been unable to find anything on the internet. Background:

• I started having erratic temp gauge on the dash, then went to cold and stayed there. Cooling fans on high all the time and stay on after car is shut off.
• Poor idling and missing (I assume due to low battery voltage)
• Had erratic codes including P3081 and mis-communication/no communications with ECU. Sent ECU out for repair, shop says no physical damage but SW malfunction. Got ECU back, car runs better, no more ECU communication errors but still had P3081 low temp.
• Replace coolant temp sensor in lower rad hose. Cleared code/MIL. Code and symptoms came back immediately.

I understand there is another engine coolant temp sensor in the engine compartment, but I have had no luck finding any information on where that location would be. I found the location and even DIY replacement procedure on every other Audi/VW engine except the 3.6!

Can anyone help!

Update:

Went to the dealer this morning to see if I could get some info.

Parts guy said the temp gauge/low temp code is probably due to aftermarket part. He spoke to one of the techs who also confirmed the problem still exist due to aftermarket part. Purchased the OEM sensor for $70! Also printed me out a diagram and confirmed that on the 3.6 there is only 1 coolant temp sensor. Got home, popped it in, and...

Problem still exists! Code/MIL won't clear, MIL on, fans on all the time at high speed.

Anyone???

Don't know if this is any use but i had similar issue finding the sensor that comms to the dash on my Audi A5. I discovered that there's Two sensors, one down at bottom rad hose and on mine the other is tucked right behind the block. Very difficult to see from top of engine. I had to show a phone with video enabled down behind top of cylinder block between engine and firewall to locate the little sod. The sensor bolts straight into cylinder block with one torx screw. If you look up the parts for your model and find there's Two types, the typical rad one that's held in via C clip but also another part that has an integrated collar with one bolt hole in then you can assume you've got a similar set up - grasping at straws a bit but who knows. I've same issue with mine regards the dodgy temp gauge and despite changing this sensor i'm talking about i've still got the same issue so even if you find it it could still be something else!!

Thanks so much for your response!

After speaking with a dealer tech at the local dealer, according to them, my setup only has one temp sensor. Guess that's why I've been chasing my tail for so long!

I believe I've got a different issue now that I've replaced the temp sensor twice already. I've started getting more and more ECU communication codes with different modules. And I did see a few posts that the temp sensor issue (erratic/zero temp gauge, fans on all the time) pointing to the ECU.

Where i'm at now is, I've ordered a used ECU and I'm trying to decide whether to send it out to a shop or try my hand at an IMMO defeat or ECU cloning.