EGT Sensors

[rah]

hey everyone, questions for my 2003 RS6.

A while back, my car went into limp mode during a drive and started leaking oil while also getting smoke out of the tailpipes under load. I took it in for diagnosis and found out that the PCV valve was stuck open and allowed oil to enter the intake system which went into the intercooler as well, causing the smoke. Ended up with about 1.5L of oil in the intercooler hoses.

Intercooler hoses were removed and the system was cleaned out, PCV valve replaced but unfortunately it also fouled my bank 1 EGT sensor and is in need of being replaced. I was told that the only way to replace those sensors is with the removal of the engine. I am not that skilled to undertake such a project and I was wondering if there is another way at all?

I also found out that there is a way to tune out the EGT sensors out but unfortunately my car is tuned and its not possible without losing the tune. Is it bad to tune them out anyways?

Lastly, if the engine has to come out, what would you recommend I do while out? The car has 119K and I was thinking to do at least timing even though it was done 18K ago, water pump, valve cover gaskets (leaking), cam seals, chain tensioner seals and cam plugs. Maybe turbos?

there is also the fact that the NLA list on the parts is getting longer for this car, so if anyone has any suggestions on where to start accumulating the parts for that project let me know please. I am in WA state if that makes a difference.

Thank you in advance for your help

[hahnmgh63]

19757
They can be removed with the engine/transmission cradle lowered, tilted down more at the back that way you can leave the coolant lines at the front connected. In the pic above you can zoom in and see the two red circles which are the two EGT sensors. I don't think they are available from an Audi dealer anymore, maybe from Audi Tradition, not sure if there is an aftermarket option. If you drop the whole assembly there are a lot of hoses and seals which will be open to replacement. Depends on how much work and how much money you want to drop into it. I've had my engine out/in twice now and with a lift it isn't difficult. I thought it was a lot of work and it does take time until I did my RS5, now that is difficult. Wish I was around in WA still then I could give you a hand but I'm a couple thousand miles away.

[hahnmgh63]

These are the part #'s for the EGT's from the ETKA catalog:

temperature sensor
3 pin left 077919529E

temperature sensor
3 pin right 077998124

repair set for temperature sensor
3 pin left a. right 8E0919521A

You might be in luck though, UK Ebay has the Right side (Bank 1) sensor listed:
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=077919529E&_sacat=63276&_odkw=077998124&_osacat=63276

[calif_kid]

I don’t have an RS6, but instead have a 2001 Audi A6 2.7T 6-speed, but I wanted to mention that you may have a few options:

You might install ‘EGT Deletes’ which are modules plugged into the EGT connectors on top of the engine for the EGT that is not working correctly, and it will then send a safe temp reading to the ECU, but you lose the safety that the EGT gives if the temp is actually too high. The install is easy, and I’ve installed a few of these on 2.7T’s, and they used to cost say $50-60 for a pair using the forums (QuattroWorld or Audizine) or E-bay. Some of the past sales and discussion for the 2.7T EGT deletes was at https://forums.quattroworld.com/classifieds-parts/msgs/28193.phtml, but I’m not sure if the RS6 could use the exact same EGT delete or if it would be different. On E-bay, nothing appears if I search for ‘EGT delete’, but searching for ‘EGT limp mode’ shows one listing for around $110, but it is for a 2.7T instead of the RS6 engine.

You might choose to open the EGT connector case under the hood, and resolder the board(s) like https://www.rs6.com/showthread.php/32494-EGT-sensor-DIY-repair-with-photos or https://www.rs6.com/showthread.php/31390-EGT-Sensor-info-and-easy-fix-(old-news) or https://www.rs6.com/showthread.php/31959-EGT-Sensor or maybe replace the old boards with new boards like https://www.audiworld.com/forums/2-7t-v6-discussion-107/how-fix-egt-sensor-good-2850845. I’ve never bought EGT boards from SID Motorsport in Poland, but I took a look, and he does list some for the C5 RS6 at
https://sidmotorsport.pl/index.php?id_product=1634&rewrite=modul-egt-rs6-42-biturbo-c5-s3-8l-18t-bentley&controller=product

Note – when I was just looking at the SID Motorsport website, I clicked on a button so the info is shown in English, but when choosing the auto type, the last range (Zakres) info was still in Polish, so I translated the choices, and they are:

CHLODZENIE - Cooling
DOLOT - Intake
HAMULCE - Brakes
INNE - Other
NADWOZIE - Body
NAPED - Drive
PAOLIWO - Fuel
SILNIK - Engine
WYDECH - Exhaust
ZAWIESZENIE - Suspension

You might be able to splice the wiring so the EGT that is working OK will send its info for both banks like is mentioned at https://www.audizine.com/forum/showthread.php/487633-Repair-EGT-sensors, but again you lose the safety net if one bank is actually too hot.

If you decide to install a new EGT, then I’m not sure how many places you could get it from, but it looks like it may be available at https://www.the-tuner.com/en/product/the-rs6-abgastemperatursensor-agt/ which mentions that they aren’t available anymore, and that their housing can fit both sides.

If you do decide to replace the EGTs, then the threads below may be of some help:
https://forum.rs246.com/viewtopic.php?t=122944

https://www.rs6.com/showthread.php/33216-How-to-change-EGT-sensors mention that RS6 (https://www.rs6.com/showthread.php/33216-How-to-change-EGT-sensors%20mention%20that%20RS6) and 2.7T EGTs are different with RS6 being ‘wideband’ like is mentioned in https://myaudis4.com/2014/06/07/rs6-egt-logs/

https://www.audiworld.com/forums/a6-s6-c5-platform-discussion-7/egt-sensor-replacement-without-access-below-2-7-automatic-2784251/ discusses EGT replacement on a 2.7T and that bank 1 (passenger side) is easy to change/access
Good luck!!! - Jim

[hahnmgh63]

I bought a set of these just for spares: https://tteglobal.com/audi/rs4/b5-2.7-v6/590/the-rs6-c5-exhaust-gas-temperature-sensors-egt-pair
I replaced mine with new OEM Audi parts around 10yrs ago as preventative Mx when I had the engine out for Miltek downpipes. I was assuming the newer Audi parts wouldn't have the circuit board issues that the originals had on many cars but I was wrong. A few years ago I had the issue with one of mine. It took me two attempts but I repaired mine, couldn't visually see the bad solder but just redid the connection shown in the post above and on the second time around it worked. So now I'll have the TTE set as spares as I'd prefer to not code out my EGT's as I am running higher boost so most likely higher temps.