My CEL is on and I need to pass an emission test to re-register. I popped the trunk and unscrewed the V6 cover and am having a hard time finding the damn thing. I gotta 97 2.8 Quattro so I dont even know if Im looking for blue or green......someone help me pleaseee. Can anyone gimme a part number too? Thanks alot.

 

Is it the sensor telling you that you are out of coolant or that your engine is too hot? If its the coolant reservoir <https://www.audiforums.com/forum/showthread.php?t=8016> .

 

you were lookin in the wrong place thats all. its not under your trunk, its under the hood

do you need the coolant temp sensor or the coolant level sensor?

 

Well I'd say youre probably looking for a blue sensor since its a 97. The green ones were updated ones. For a V6 I think it was a little harder to get to. I know theres a DIY writeup around somewhere...

 

I think it’s the same as my 99 A4q 2.8.

Assuming it's the engine block coolant sensor it's blue for the Pre 2000 years but you don't see much until you really get to it. I got one from Napa for about $18 and it's made by behr (good quality)

It's on the back side next to the firewall, beneath the throttle body and offset to the passenger side a bit. It's a drag to get at it but do-able. I had to move some parts out of the way and remove the air pipe between the airbox and the throttle body to even see it and then you can only get one (small) hand down in there to work.

Use a flashlight and look down between the eng and firewall standing at the passenger side fender area, the sensor is vertically mounted. It has one of the metal retaining clips then you depress and then pull the connector straight up. The sensor is held in by a plastic U-shaped clip that is horizontally pushed through the top of the block where the sensor enters, you can snag this with a screwdriver to pull it out.

I was told to clamp the radiator top tube to avoid too much coolant loss, it will **** coolant when you pull the sensor out; I think I only lost about a quart (be sure to top of with G12). You’ll need a pick of some sort to gently snag and lift the oring out of the block after pulling the sensor and the coolant is done leaking out (if you choose to replace the oring which did come with the behr sensor). I was also recommended to lightly grease (Vaseline) the oring, install the oring first and then push the sensor in.

Putting the new sensor in was a pain in the a$$ with one hand, it took a good 10 minutes for me and I have small hands, only one hand will fit in there anyway.

Hope that helps.

 

thanks man, Im going to try to find that ****, but its good to know I need the blue. do u know how many pins it is? There is a NAPA near my house and I think I am going to order the part thru them first. The car is running fine and everything, it has coolant n all, but the idk the CEL is on and the temp gauge always seems to be at cold.

 

Perhaps you should have the code read to know exactly what is causing the CEL, you might have other problems.

 

These sensors are known for going bad and it will cause your temp gauge to read cold or bounce around plus it will mess with your ecu because it will think the engine is cold when its hot and your emissions will be whacked.

Here, look at this link to Arizona autohaus (these guys rock too), it shows all the parts. P/N 078919501B http://www.autohausaz.com/search/pro...ber=078919501B