07 - S6 Coolant in oil - Complete Engine Teardown

A6 All/ S6 All
#101

No, I am still using the original oil cooler.

I thought I made a post regarding this but could not find one when I went back through this thread.

I did a low pressure test on the coolant side. I plugged the coolant pipe on one side of the cooler and then filled the oil side of the heat exchanger with solvent. I then connected a regulator and an air line to the open coolant pipe. I set the regulator at about 15 psi and then watched for signs of bubbles to surface in the solvent. None had appeared after about 20 minutes so I considered it a pass.

#102

I have put about 1600 km (~1000 miles) on it in the last few weeks and everything is good so far. It is running better now than it has in the last three and a half years that I have owned it.

My coolant level in the reservoir has been rock steady. Prior to the engine rebuild, I would have added at least a litre by now given the distance driven.

I had it on the lift last night and did not come across any signs of early oil leaks.

Also, I think it is the first time ever that my misfire counts have all been zero for any length of time.

http://audirevolution.net/addons/albums/images/576199894.jpg

Only time will tell how long that will remain the case.

#103

Whoa, hold on! How do you get the scan tool to come up the the MMI screen?

#104

So glad all this hard work has ended up in such great results.

What would be the top 5 things that you found in the rebuild that everyone should know.

Also that is neat on the vag com. Is that via aux port? Do you have full control?

#105

assuming that’s some sort of Android box replacement for the MMI

#106

This thread is legendary and in my opinion should be permanently posted to the top of the S6 page.

Also now that the rebuild was deemed a success, what’s your verdict as to the cause of the disappearing coolant?

I imagine it could be a combination of things but i’m curious what you think having gone through the motor with a fine tooth comb.

#107

I don’t recall there being anything totally unexpected or especially noteworthy during the project.

If you have patience, perseverance, the tools and the FSM, you just take your time and work through it methodically.

Unless you have severely overheated your engine to the extent that I did, there should be no need to tear things down to the bare block. If you do need to do this, then:

  • Organization is key – group, bag and label all your smaller parts during disassembly

  • Take lots of pictures during disassembly – especially the electrical and plumbing

  • Use an online Audi parts database to identify all the seals and bolts, etc. that you need as you work through the disassembly process – This should save you some time and frustration at the dealership. I would just email my parts lists to the local dealer and then pick them up the next morning.

It is an Android touchscreen communicating wirelessly with the HEX NET interface in AP mode.

I originally installed the touchscreen last year so I could run a more modern navigation app. It was only after I installed it that I realized I could just install VCDS mobile and not have to use my phone or laptop.

The MMI interface is still there. An FM transmitter broadcasts it to the touchscreen. It automatically switches to the back-up camera image when you shift into reverse.

#108

I never did really find any obvious signs that any of the coolant pipe/passage seals were leaking when I did the teardown.

I know in Greg50H’s case, the leak was at the o-ring seals where the internal coolant pipes run through the cam covers at the back of the engine. I inspected all four of my seals and there was no erosion of the o-rings or the seats.

After changing every seal and gasket in the engine, I have not seen any coolant loss in the thousand miles I have racked up so far. It may still be leaking internally, but it would be at a greatly reduced rate compared to what it was.

I will be looking forward to seeing the Blackstone results after my first oil change.

1 Like
#109

Excellent documentation of this build process. Thank you for doing it. The time and cost seems daunting to rebuild the motor, but I thank you for doing it.

#110

@eng92 what an awesome thread (need more words to describe how cool this is) it is a dream of mine to do this some day.

by any chance do you have the original photographs from the build? none of the links in the thread seem to be working, this might be a factor of the forums moving to the new format.

Even more ideal would be if a moderator could somehow get these links to work once again.

#111

This thread and some CV threads must be preserved with pics, at a minimum. Visitors seeing these threads will drive more traffic to the forum. I know it’s easy for me to say, because I don’t know what’s involved, but you can already see forum traffic has all but died. This was the PREMIER forum for S6 knowledge; we need to keep it that way.

#112

Whats up with the missing pics?

#113

@eng92 been a long time… would love to get an update on the build.
Also did you upload the pics to a separate site, not sure why they are working anymore.

#114

This thread was recreated with the pictures restored.

https://forums.audirevolution.net/t/07-s6-coolant-in-oil-complete-engine-teardown-with-pictures-re-stored/16384/5