Guide: How not to "replace" an EGT sensor.... long
06-06-2009, 12:04 PM
#1
AudiWorld Super User
Thread Starter
Guide: How not to "replace" an EGT sensor.... long
Preface:
About a month ago, I broke down and purchased a vag-com cable. Needless to say, my car which had been operating without any issues for months had issues. Largely this issue was a driver's side EGT sensor beginning to fail. Lovely.
So like most people I began the long task of sourcing an EGT sensor for less the 1/20 the cost of a replacement S4. I stumbled across a used one on AZ classified for $50 shipped. He had the 2000MY manual which used 2 black sensors. (The driver's side EGT on my car is black with the passenger being the brown. I have a tip, yours could be different. And no, I don't wear panties...)
So after sitting on the part for a couple weeks, it was time to install it. I had read that it was best to do this from the underside of the car. Needless to say I didn't want to deal with jack stands, so I did the only logical thing to do and called up a shop and rented their lift/shop for a night at the rate of 1.75 of Crown Royal. Note to Canadian readers: Crown is much cheaper in the states, around $45 for this glorious bottle. I suggest drinking around 2 to 2.5 liters a month. It seemed to keep away nearly all sickness my junior and senior year in college... Your results may vary...
Back to the topic on hand. Once I had scheduled the lift, I decided I might as well take care of some other things that a lift would help do. Therefore, I ordered new front control arms, shocks, springs, front axles, and all 4 wheel bearings. I purchased a press to assist in the wheel bearings.
Needless to say, you *may* require less components to perform your EGT sensor replacement. Although I don't see how.
Process:
Day 1:
1. Break loose all 4 hub bolts with a good impact or a long breaker bar. I've had good luck with Proto allen sockets and Snap-op breaker bars.
2. Put car on lift. I recommend using hockey pucks to adapt a lift for use on our pinch welds. Works flawlessly and no damage to the seams/floor what so ever.
3. Remove the front brake calipers, rotors, sensors, upright, control arms, shocks, and springs.
4. Assemble the new front shock and spring assemblies.
5. Press out and repress in new bearings.
6. Replace front control arms, axles and uprights.
7. Replace brake rotors, calipers, and finally wheels. Convince yourself that the rears will take less time.
8. Remove the rear wheels.
9. Attempt to remove the rear caliper. Realize that the pads are locked down on the rotor because the last thing you did is step on the brakes without moving the car. Use die grinder to remove the outer edge around the rotor to allow the caliper to slide off the rotor with ease. Attempt for 5 min to get the rotor off. Redefine your definition of ease. Grab 3 foot crow bar and pry the rear caliper off of the rotor. Repeat on other side.
10. Remove the uprights and do the rear bearing job. In my case the inner outer race of the wheel bearings had to be cut out of the rear uprights.
11. Perform the shock and spring job on the rear.
12. Reassemble the rears.
13. Realize you had put a brake line in the wrong position and you must redo some work to get it into the right place.
14. At this point, you realize the whole point of the lift was the EGT sensor. Attempt for 10 minutes to find out where the driver's side EGT sensor is. Fail miserably. Determine you will replace it without the lift since it is approaching 1AM.
15. Drive your car home with one of the rear dust shields rubbing a rotor. Fix the shield and call it a night.
Day 2 (and beyond):
1. Wake up early determined to replace the EGT Sensor and coolant expansion tank.
2. Remove old tank, y pipe, both EGT sensor's bodies, and begin the hunt for the EGT.
3. Find EGT, attempt to loosen the heat shield. Fail and strip out the bolt. Attempt a larger Allen, also fail.
4. Still determined, spend an hour trying to get sockets and crows feet and whatever else in from all sorts of angles. Still fail.
5. Convince yourself that the problem probably wasn't due to a failure the thermocouple portion. Pop open the EGT sensor that you replaced from the passenger side 4 years ago.
Convince yourself that swapping the electronics from one package to the other is your best option.
6. Remove the electronics board from the $50 EGT you picked up. Notice on the original one you have, only the ECU side of the sensor has been soldered. This one has both the ECU and Thermocouple side soldered. Rejoice as this should improve your chances of success.
7. Remove the cover and electronics from your existing sensor while still on the car.
8. Replace the "new" electronics board into the old sensor body.
Both the boards, old and new. They are covered in something kind of like jello. It does not melt at engine temp as it did not settle to the bottom of the body.
All done.
9. Replace the cap on the EGT sensor with hot glue. Replace Y pipe, and new coolant expansion tank.
10. Take car for a spin.
11. Notice a new vibration while your car is under acceleration. Freak out, and post trying to figure out what you did that caused it. Decide you have a failing drive shaft.
12. Scan for codes, EGT sensor is still broken.
13. Decide you will replace the drive shaft at a shop close to your apartment and call it done.
14. Leave the car with your parents for the week while your take your mom's Trail Blazer back on the 700 mile trip to your apartment.
15. The shop you scheduled your alignment at can't align it because the camber is too far out of spec. for their equipment to handle.
16. Schedule an alignment at the VW shop, cross your fingers.
17. The car was finally aligned, camber way out of spec.
18. Your parents drive the car back to you and meet you at your college graduation.
19. Try to get a local shop to perform the drive shaft replaced. They can give me estimates, but cannot do the job because I want to use a rebuilt drive shaft supplied by myself.
20. Decide that you will do a 6mt conversion which will ultimately replace all the components which could have caused the vibration.
21. Think to yourself that you might as well do a turbo job while you're going to pull the engine anyway.
22. Create a mental note to replace the EGT sensor while you're doing the turbos and the conversion...
23. Post the longest post of your life on audiworld.
*24. Still to be done. Edit your post on AW many times to fix all the errors.
About a month ago, I broke down and purchased a vag-com cable. Needless to say, my car which had been operating without any issues for months had issues. Largely this issue was a driver's side EGT sensor beginning to fail. Lovely.
So like most people I began the long task of sourcing an EGT sensor for less the 1/20 the cost of a replacement S4. I stumbled across a used one on AZ classified for $50 shipped. He had the 2000MY manual which used 2 black sensors. (The driver's side EGT on my car is black with the passenger being the brown. I have a tip, yours could be different. And no, I don't wear panties...)
So after sitting on the part for a couple weeks, it was time to install it. I had read that it was best to do this from the underside of the car. Needless to say I didn't want to deal with jack stands, so I did the only logical thing to do and called up a shop and rented their lift/shop for a night at the rate of 1.75 of Crown Royal. Note to Canadian readers: Crown is much cheaper in the states, around $45 for this glorious bottle. I suggest drinking around 2 to 2.5 liters a month. It seemed to keep away nearly all sickness my junior and senior year in college... Your results may vary...
Back to the topic on hand. Once I had scheduled the lift, I decided I might as well take care of some other things that a lift would help do. Therefore, I ordered new front control arms, shocks, springs, front axles, and all 4 wheel bearings. I purchased a press to assist in the wheel bearings.
Needless to say, you *may* require less components to perform your EGT sensor replacement. Although I don't see how.
Process:
Day 1:
1. Break loose all 4 hub bolts with a good impact or a long breaker bar. I've had good luck with Proto allen sockets and Snap-op breaker bars.
2. Put car on lift. I recommend using hockey pucks to adapt a lift for use on our pinch welds. Works flawlessly and no damage to the seams/floor what so ever.
3. Remove the front brake calipers, rotors, sensors, upright, control arms, shocks, and springs.
4. Assemble the new front shock and spring assemblies.
5. Press out and repress in new bearings.
6. Replace front control arms, axles and uprights.
7. Replace brake rotors, calipers, and finally wheels. Convince yourself that the rears will take less time.
8. Remove the rear wheels.
9. Attempt to remove the rear caliper. Realize that the pads are locked down on the rotor because the last thing you did is step on the brakes without moving the car. Use die grinder to remove the outer edge around the rotor to allow the caliper to slide off the rotor with ease. Attempt for 5 min to get the rotor off. Redefine your definition of ease. Grab 3 foot crow bar and pry the rear caliper off of the rotor. Repeat on other side.
10. Remove the uprights and do the rear bearing job. In my case the inner outer race of the wheel bearings had to be cut out of the rear uprights.
11. Perform the shock and spring job on the rear.
12. Reassemble the rears.
13. Realize you had put a brake line in the wrong position and you must redo some work to get it into the right place.
14. At this point, you realize the whole point of the lift was the EGT sensor. Attempt for 10 minutes to find out where the driver's side EGT sensor is. Fail miserably. Determine you will replace it without the lift since it is approaching 1AM.
15. Drive your car home with one of the rear dust shields rubbing a rotor. Fix the shield and call it a night.
Day 2 (and beyond):
1. Wake up early determined to replace the EGT Sensor and coolant expansion tank.
2. Remove old tank, y pipe, both EGT sensor's bodies, and begin the hunt for the EGT.
3. Find EGT, attempt to loosen the heat shield. Fail and strip out the bolt. Attempt a larger Allen, also fail.
4. Still determined, spend an hour trying to get sockets and crows feet and whatever else in from all sorts of angles. Still fail.
5. Convince yourself that the problem probably wasn't due to a failure the thermocouple portion. Pop open the EGT sensor that you replaced from the passenger side 4 years ago.
Convince yourself that swapping the electronics from one package to the other is your best option.
6. Remove the electronics board from the $50 EGT you picked up. Notice on the original one you have, only the ECU side of the sensor has been soldered. This one has both the ECU and Thermocouple side soldered. Rejoice as this should improve your chances of success.
7. Remove the cover and electronics from your existing sensor while still on the car.
8. Replace the "new" electronics board into the old sensor body.
Both the boards, old and new. They are covered in something kind of like jello. It does not melt at engine temp as it did not settle to the bottom of the body.
All done.
9. Replace the cap on the EGT sensor with hot glue. Replace Y pipe, and new coolant expansion tank.
10. Take car for a spin.
11. Notice a new vibration while your car is under acceleration. Freak out, and post trying to figure out what you did that caused it. Decide you have a failing drive shaft.
12. Scan for codes, EGT sensor is still broken.
13. Decide you will replace the drive shaft at a shop close to your apartment and call it done.
14. Leave the car with your parents for the week while your take your mom's Trail Blazer back on the 700 mile trip to your apartment.
15. The shop you scheduled your alignment at can't align it because the camber is too far out of spec. for their equipment to handle.
16. Schedule an alignment at the VW shop, cross your fingers.
17. The car was finally aligned, camber way out of spec.
18. Your parents drive the car back to you and meet you at your college graduation.
19. Try to get a local shop to perform the drive shaft replaced. They can give me estimates, but cannot do the job because I want to use a rebuilt drive shaft supplied by myself.
20. Decide that you will do a 6mt conversion which will ultimately replace all the components which could have caused the vibration.
21. Think to yourself that you might as well do a turbo job while you're going to pull the engine anyway.
22. Create a mental note to replace the EGT sensor while you're doing the turbos and the conversion...
23. Post the longest post of your life on audiworld.
*24. Still to be done. Edit your post on AW many times to fix all the errors.
Last edited by complacentsee; 06-08-2009 at 06:59 PM.
06-07-2009, 12:41 PM
#6
AudiWorld Super User
Thread Starter
As a side note. Due to the price of crown in Canada being artifically raised, it would be foolish to drink it... As far is visiting americans go, who knows... I would be taste testing some Cuban rums since it would be a rarity to have them in the US.
Lastly, I personally like Crown. It is priced "competitivly" with other popular wiskeys such as Jack. It totally kills jack IMHO. Anything priced less is basically total ****, and is similar to Cuervo branded tequilas in that they are just generic alcohol with coloring and flavoring...
My goal was not insulting canadians. Just that I relized that saying "1.75 of crown royal" is rather ambiguous. And while I was on the topic, I figured I might aswell mention it was my whiskey of choice in my college days. Primarily because it was cheap enough to be an affordable "lets get black out tonight" beverage.
06-07-2009, 01:12 PM
#7
AudiWorld Super User
Thread Starter
Sure did. Came/comes back upon starting car. Has not started to effect driving performance. I just don't want to be running really high EGTs and damage my turbos.. With any luck these k03s won't keep me up at night for too much longer.
Trending Topics
06-07-2009, 01:18 PM
#8
AudiWorld Super User
Thread Starter
Also, there could be an issue with one of my soldering points being a poor connection. Although I would have imagined that giving me an open circuit dtc vs a short to ground. Then again, I don't know how smart the sensor/motronic is.
06-07-2009, 05:18 PM
#9
AudiWorld Super User
Join Date: Oct 2002
Location: Seattle area
Posts: 10,857
Likes: 0
Received 0 Likes
on
0 Posts
what specific EGT codes did you have? Short to ground or open circuit can be either sensor or wire harness issue. Short to ground possible from wire harness abrasion, since signal wire can get shorted to chassis (ground).
Bruce
Bruce
06-07-2009, 05:25 PM
#10
AudiWorld Super User
Thread Starter
I'll swap the banks to see if the code swiches sides. It did go from intermittent to constant though. But that could have been due to the 800 miles I put between code scan and "repair".