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Replacing Engine Coolant Temperature Sensor (ECT) - Long

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Replacing Engine Coolant Temperature Sensor (ECT) - Long

 
Old 08-14-2010, 01:24 PM
  #21  
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Default Thanks for your help!

Originally Posted by chianm View Post
Just replaced the ECT on my 2000 A6 2.8Q. It didn't take too long to replace, with the exception of figuring out how to pull the clip and harness connector out with my *big* hands. If I didn't know any better, I'd think that the assemblers for this car were midgets.

***WARNING***
BE SURE TO WORK ON THIS ONLY WHEN THE ENGINE HAS COOLED OFF. YOU CAN SERIOUSLY BURN YOURSELF IF THE ENGINE IS STILL HOT WHILE PERFORMING THIS TASK.

***DISCLAIMER***
THIS IS INFORMATIONAL ONLY.

-----

OK, now that's out of the way. Here it goes. First, I had to get the parts. The part numbers are:

ECT: 059 919 501A - $3.91 (www.thepartsbin.com)
O-Ring: N-903-168-02 - $5.25 (Audi Dealership)
Retention Clip: 032-121-142 - $0.91 (Audi Dealership)

<img src="http://pictureposter.audiworld.com/83960/img_0132.jpg">

The fun begins here:

First remove all covers in the engine bay. Then remove the flex hose that connects the air box to the motor.

<img src="http://pictureposter.audiworld.com/83960/img_0134.jpg">

Next, locate the sensor. It's located under the solid hose that is connected to the motor. The sensor is mounted on top of a tube coming out of the engine. (See Picture)

<img src="http://pictureposter.audiworld.com/83960/img_0135_-_marked.jpg">

Here is a close-up of the sensor.

<img src="http://pictureposter.audiworld.com/83960/img_0136.jpg">

Here is the tricky part. To remove the sensor, you need to find a way to get your hands in and around the sensor. There is only enough room for your left hand to squeeze through. Twist the connector until you can get either your thumb or index finger on the retaining clip holding the connector onto the sensor. *PUSH* on the connector down as if you are trying to plug it in. THEN SQUEEZE the retaining clip on the connector. Then and only then will the connector want to come off of the sensor. (You need to try this a few times.)

When you get the connector off, put it aside of the sensor.

<img src="http://pictureposter.audiworld.com/83960/img_0138.jpg">

After taking the connector off, the rest of the job is a lot easier.

You will need to wear rubber gloves and a pan under the car for this. Coolant will get all over the place.

Get a good grip on the sensor retaining clip. It's going to take some massaging to pull it out. The trick that I used is first pull on the clip with my thumb and index finger. When it would nudge out a bit, I would stick part of my middle finger in between the clip and the sensor as a wedge. Then I would relocate my thumb and index finger again to get a better grip. Do this a few times and eventually the retaining clip will pop out.

When the clip pops out, the sensor will be loose to be removed. When you pull the sensor out, coolant will spill out, as pressure in the system will be released through the path of least resistance.

Remove the sensor. Check to see if the O-Ring is still stuck to the sensor. If the O-Ring is not on the sensor, it is most likely still on the tube. Stick your finger into the hole and fish out the O-Ring.

Place the new O-Ring on the new sensor:

<img src="http://pictureposter.audiworld.com/83960/img_0133.jpg">

Insert the sensor into the hole on the tube. Use the NEW retaining clip and push it around the sensor holder until you hear a "CLICK". Check the sturdiness of the clip by wiggling the sensor.

Reinstall the connector onto the sensor. Make sure the orientation of the D-Clip Backshell is correct. Then push the connector onto the sensor.

The job is almost done. Just need to clean up and reinstall all the plastic covers back on.

Be sure to reinstall the flex hose onto the airbox. It's cooled off and is a bit harder to put back on. Make sure it's sturdy before clamping it back on.

You are now done.

Could not agree more with you about the big hands problem. Your instructions were very helpful. I would like to add however that it was easier for me to pull the retainer clip out first, then the sensor with the harness still attached. That way once it is out you have a much better chance of getting the connector off. At least it was for me. I found that it was difficult to get it back in actually. It was a b*tch to get the retainer clip back in. Had my wife reach in there with her little hands at my direction. Pretty watching her work and ME holding the light....lol....thanks again!
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Old 03-05-2011, 12:56 PM
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I had the same issue with my '98 A6. Nearly word for word, I had the same issue with mine. Your pics and write-up were outstanding! I have a couple of tips to help with the overall process.
1. Take off ALL the plastic covers so you can lie longitudinally across the front of the engine (This works best when you'e let the car sit overnight to cool off).
2. Using a flashlight or worklight in your right hand, use your left hand while laying over the top of the engine. This way you are basically 4 inches from the sensor. It is also easier, and more ergonomic to work the sensor lead, clips and sensor itself out of the porthole.
3. In order to get the old clip off, tie a zip-tie around the clip noose. Make it big enough so you can pull with two fingers. Once you have the zip-tie on, pull the old clip straight out. I found this worked perfect.
4. When you put the new sensor in, make sure it does not go in on an angle. You may have to run a finger into the porthole beforehand to make sure there is no buildup or residue that will hamper the seating of the o-ring and new sensor.
5. If you're unsure of how the new clip should fit, practice or explore first with a paperclip. This way you won't damage the new clip, they are only plastic. Also, make sure the new clip has not been outside in a cold car. It will likely be brittle and break when you go to install.
6. So that you don't drop the new clip into the engine, tie some string or fish line to it and have it tied off to the car. That way if you do drop it you can easily pull it back up.
7. The coolant WILL flow freely from the porthole after you take out the old one. In fact, ALL of the coolant will empty from the reservoir. Ensure to have the Audi/Volkswagen specific coolant at the ready. If you don't have it for this project, you will have make another trip to Audi to get the coolant before starting the engine.

These are just some tidbits I found helpful doing this job. Leaning over the engine facing into the windshield - not from the side of the car - really paid off. As did the tie clip, and fish line for the new clip installation.

Thanks again for the ECT insight and pictoral post. You likely saved my several hundreds of dollars in diagnostic fees, fuel pumps and plugs I would not have needed.

Cheers.
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Old 09-18-2011, 07:03 PM
  #23  
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draining about a gallon of coolant off the top using gravity will keep the spillage to 0%.
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Old 02-17-2013, 06:16 AM
  #24  
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Default No way can I get my large hand even near this

Originally Posted by musqhbr View Post
I had the same issue with my '98 A6. Nearly word for word, I had the same issue with mine. Your pics and write-up were outstanding! I have a couple of tips to help with the overall process.
1. Take off ALL the plastic covers so you can lie longitudinally across the front of the engine (This works best when you'e let the car sit overnight to cool off).
2. Using a flashlight or worklight in your right hand, use your left hand while laying over the top of the engine. This way you are basically 4 inches from the sensor. It is also easier, and more ergonomic to work the sensor lead, clips and sensor itself out of the porthole.
3. In order to get the old clip off, tie a zip-tie around the clip noose. Make it big enough so you can pull with two fingers. Once you have the zip-tie on, pull the old clip straight out. I found this worked perfect.
4. When you put the new sensor in, make sure it does not go in on an angle. You may have to run a finger into the porthole beforehand to make sure there is no buildup or residue that will hamper the seating of the o-ring and new sensor.
5. If you're unsure of how the new clip should fit, practice or explore first with a paperclip. This way you won't damage the new clip, they are only plastic. Also, make sure the new clip has not been outside in a cold car. It will likely be brittle and break when you go to install.
6. So that you don't drop the new clip into the engine, tie some string or fish line to it and have it tied off to the car. That way if you do drop it you can easily pull it back up.
7. The coolant WILL flow freely from the porthole after you take out the old one. In fact, ALL of the coolant will empty from the reservoir. Ensure to have the Audi/Volkswagen specific coolant at the ready. If you don't have it for this project, you will have make another trip to Audi to get the coolant before starting the engine.

These are just some tidbits I found helpful doing this job. Leaning over the engine facing into the windshield - not from the side of the car - really paid off. As did the tie clip, and fish line for the new clip installation.

Thanks again for the ECT insight and pictoral post. You likely saved my several hundreds of dollars in diagnostic fees, fuel pumps and plugs I would not have needed.

Cheers.
I have seen in the tech article by Kris Hansen, he removed the intake duct from the throttle body. Are there in pitfalls in doing that? I see that there is a allen bolt facing the firewall on a good day I may be able to get it out, but replacing it may be a challenge. Does anybody have any favorite grabbing tools to get this job done?
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Old 02-17-2013, 06:49 AM
  #25  
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Originally Posted by cosmicbud View Post
I have seen in the tech article by Kris Hansen, he removed the intake duct from the throttle body. Are there in pitfalls in doing that? I see that there is a allen bolt facing the firewall on a good day I may be able to get it out, but replacing it may be a challenge. Does anybody have any favorite grabbing tools to get this job done?
I removed the intake duct when doing some of that black corrugated snaky tubing replacement and it was pretty easy to get it off. I think only 2 or 3 bolts and it comes off. You might have to move some vacuum stuff out of the way but it does open up the back of the engine so you can get at your sensor.

Good luck!
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Old 06-03-2013, 06:27 PM
  #26  
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Hello,
1st post. I need advise ASAP. I just changed my ect. It went fine and I put everything back together. But when I went to start the car the engine would not turn over. The bells and whistles came on inside the cabin (lights beeps and notifications) but the engine did nothing. I was hoping someone could tell me if this is "common", ie my big hand bumped something near the ect and it is an easy fix.

Thank you in advance.
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Old 06-04-2013, 02:10 AM
  #27  
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does it just crank and crank with no fire?
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Old 06-04-2013, 02:56 AM
  #28  
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Probably should have started a new thread for this.

Battery?
Starter?
Ignition switch?

I'd probably start by making sure the battery is fully charged.
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Old 06-04-2013, 04:16 AM
  #29  
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wow cant think of what would kill everything in that area .. you didnt happen to leave stuff on and kill the battery did you ?
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Old 06-04-2013, 07:17 PM
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There is no crank whatsoever. Today I replace the new ect with the old one. Just to verify that it is not the new ect conflicting with the computer. No go, no crank. The battery seems fine. But I will give it a jump tomorrow and try to crank it. I was wondering, while I had the maf sensor off I cleaned it with maf cleaner. But I only waited 10 min or so before attempting to start the car. Would this affect the system? Ie. fry something. Also, I forgot to unplug the battery before replacing the ect. Would this have fried something?

If I were to look for the starter where would I find it in an a6 Quattro 2.8? A site said to hit it with a broom handle to get it to work if it were to stall.

Thanks again.
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