Can anyone tell me where the coolant temperature sending unit is located on a 99 A4 V6 5 valve engine? I found the string on changing the temp. sender but the pictures must be from 1.8 because it does not appear to be in the same location on my V6. Any help would be appreciated.

 

It's at the back of the engine, passenger side, behind and below the head. Take off the tube from airbox to throttle body and look down. The connector plugs into the top and has four wires in a square pattern around 3/4" on a side. The sensor body will likely be blue but may be green. Be sure to get a new retaining clip also as it's plastic and may break when you remove it.

 

make sure the engine is cool or the pressure will shoot coolant up when you remove the sensor. The plastic clip pulls out to the side, not up. If you break it you will not be able to drive the vehicle, so get a replacement from the dealer first (I couldnt find one at any parts stores). go ahead and clean the oxidation from the connector while you're at. If you're really zealous, go ahead and clean all the connectors you can find.

 

Not to mention it's pretty deep-seated behind the engine, if you're going to try and wedge your hand back there to get it out, you'll really want it to be cooled off or risk a very uncomfortable or painful job.

 

Thanks for all the quick responses. This is a big help. I need to get a Bently service manual.

 

Is this coolant temperature sensor G62 we're talking about? I might have to replace this too since I had a P0118 code when I ran my car through vagcom. I also read on ecs tuning that the green plug is the improved version.