Playing with an Audi SQ5 TDI

[Lucas_R]

Heya - decided to start a new thread as the other one was a bit of a mess.

In August 2018 I purchased a 2015 model Audi SQ5 for the wife to drive around and to be our primary family car. Needed something with some boot space and practical so we can fit our young child as well as large-ish dog etc. But apart from practicality, both the wife and I are car enthusiasts and love having powerful cars.

This is the 230kw / 650nm model with the 3.0TDI V6 biturbo and 8 speed ZF auto. My brother who worked at the local Lexus dealership at the time sourced it for us, it has just turned 3 yrs old, 1 owner and had done 29,000km (I assume it was a lease car) and came from Melbourne.

The car was very well spec'd, with only the black grill/window trim being the only desirable option not on the car - but it had the much more attractive quilted leather seats, 21" rims, Bang & Olufsen stereo (which pumps), carbon interior trim, heated seats, radar cruise and panoramic sunroof. The RRP on this car new with the options fitted would have been approx $113k, we paid $66k.

The car was due for its 3rd service, so was swiftly booked into Pete @ Newcastle VW Centre for the service.

Shortly after the service, we got a recall letter from Audi to replace the heater coil unit, so that was done too.

Things that might interest you:

• Stage 1 tune from Underground Performance
• Wagner intercooler
• AFE replacement air filter
• RSNav S4 10.25" infotainment upgrade with Apple Carplay
• Audi Q7 SLine 21x9.5" ET31 rims with 265/40/21 tyres
• Flashlube Catch Can Pro (replaced early 2024 with a Process West catch can)
• 034 Motorsports rear diff carrier inserts
• 034 Motorsports diff carrier inserts
• 034 Motorsports rear swaybar and Moog endlinks
• Akebono Euro Ceramic brake pads

[Lucas_R]

6 months later...........

Gave the old girl an oil change. It was serviced about 7 months ago/8,000kms ago (by Pete @ Newcastle VW Centre) but I always like doing 6 month oil changes so I figure ill do one myself in between each "log book" service.

I enjoy doing the oil changes myself, and it gives me a chance to study the engine/driveline and inspect for any issues/leaks/worn items. The sump, swaybar, subframe and undertray were a bit grotty (presumably from previous sloppy oil changes as there are no leaks) so I gave everything a good degrease and clean while I was in there.

The cabin filter was dirty and had been starting to smell a bit the past month or two so in went a new one.

It was the first time I had done an oil change on this car so I was pleasantly surprised to see that its an easy car to work on which was both welcomed and surprising.

Also changed the brake pads all round to Bremtec Euroline Ceramic which are less dusty than the stock pads but still too dusty for my liking, so will source some ATE Ceramic or Akebono Euro Ceramic pads in the near future.

[Lucas_R]

Bought a Catch Can for the old girl recently. I went straight into looking at the Provent due to its popularity but its quite large (lengthwise) and i couldnt find a suitable area in the busy engine bay to be able to fit it. Ended up finding the Catch Can Pro which is also German made with similar specs to the Provent, but a little smaller in overall size and i have made a mounting bracket to secure it behind the passenger side headlight.

Catch Can Pro - Genuine Flashlube

The RRP is around the $280-300 mark but I got it via a special order from Supercheap Auto when they had a sale recently for just over $200. Its German made, nicely designed and has the 19mm inlet and outlet same as the Provent.

There are no kits (i have Googled extensively) to suit the 3.0TDI bi-turbo which I found weird considering this engine is quite popular and used in various Audi/Porsche models, so I have purchased some 19mm oil hose and various fittings etc to be able to mount it onto the car. Only one of the cam covers has the breather/PCV mechanism with that accordion hose feeds back into the intake just before the primary turbo - so this is where i will be tapping in and letting the catch can clean the air.


Who doesnt like a OEM billet compressor wheel? You can see the spot where the PCV plumbs back in just before the turbo.





1st turbo up top, 2nd turbo hiding down below.





Tapping into the factory PCV accordion hose that goes between the valve cover and the turbo inlet pipe. I used the fittings but cut the hard plastic hose off.





Catch can location (had to make a custom bracket to mount it securely).





End result. I need to get half a dozen hose clamps which i will get this weekend but for now every connection has a zip tie holding everything together.

[ZR36]

Haha i love this vid about catch cans
So many puns and 1 liners had ,me in stitches all the way through.
Geniarse 😂
The truth about oil catch cans: Should you fit one to your car? | Auto Expert John Cadogan - YouTube

[Lucas_R]

Haha i love this vid about catch cans
So many puns and 1 liners had ,me in stitches all the way through.
Geniarse ��
The truth about oil catch cans: Should you fit one to your car? | Auto Expert John Cadogan - YouTube

Yes I have watched that video previously. He raises some good points definitely. Certainly a waste of time to fit a cheap catch can off ebay that costs <$50, these are just an empty can that will do basically nothing and the vast majority of them have tiny inlet and outlet ports which would be too small for a 4 cylinder engine, let alone a powerful turbo V6. There are specific catch cans made for diesel engines (Mann&Hummel Provent, Flashlube Catch Can Pro etc) which have a fine cloth filter inside to catch the oil vapour, and have and internal diaphragm and flow enough air to accomodate larger powerful diesel engines without being a restriction.

I see what my catch can removes from the intake, as I empty it every 3 months or so - and even though perhaps 50% of this may be effectively burnt off through the engines normal cycle, id rather it be captured and removed. Im all for anything I can do to reduce the carbon buildup in the engine - only the best diesel used, high quality oil & filter changed every 6 months, air filters and fuel filters etc changed before schedule.

[Lucas_R]

It wasn't long before I was looking at remap's for the SQ5 (not that it really needed any more power, but why not). After considering the options below and speaking to all of the companies, I decided to go with Underground Performance because i know Alex and also the remote tune option was attractive to me. He also agreed to try and turn off the EGR for me (which didn't work in the end).

The tunes all all quite similar in that they quote approx+25-30kw and +90-100nm.

- Superchips (on sale, very cheap - tune via hand controller)
- Celtic Tuning (via Zadtec Performance in Sydney). Remote tune or visit workshop in Sydney.
- Tarmac Engineering (tune via hand controller)
- Underground Performance (remote tune)
- Tunes that Transporter sells through MRL Automotive (unfortunately he cannot tune remotely, and seeing I am in NSW and he is in SA this option is not realistic)

Long story short, the car is finally tuned and running well, but boy oh boy was it an effort. The remote tuning process didn't work (tried several times on different days). Drove to what seemed like the end of the world (Ingleburn, Sydney - a fair drive from Newcastle) to have the tune done by Underground Performance dealer, Pacortech. This process took about 3 hours and then i left with what I was told was a stage 1 tune and EGR delete.

Drove home, everything seemed fine, then about a week later I decided to check my VAGDPF app which I use to keep an eye on the car's DPF and it's regen's - and the app is telling me that the DPF hasnt done a burn in 800km. Hmmm this is odd im thinking as this car religiously does a DPF regen every 500km or so. This carried on for a good 4-6 weeks with the car not doing a DPF regen (and yes I contacted Underground about it - was told its fine but I knew something was wrong). Then a few weeks later ive got warning lights on the dash, and reduced performance. And a week or so after that im in limp mode with about 5kw. All this in the week before Christmas - so right when you need the car and right when Underground closes for Xmas.

Thankfully Alex from Underground sent me a CMD Flash tool which (along with software) allowed me to put the car back to its stock map - which then told me that the DPF was 588% full (yikes). I had to physically remove the 2x DPF's off the car and flush it out with my Gerni, then reset the DPF using VCDS which THANKFULLY put the car back to normal.

After a good 8-10 days of driving around successfully with the stock map on the car, I was able to flash it to a normal stage 1 tune (no EGR delete) and the car has been running fine since.

Turns out the original remap put on the car messed up the DPF signals so the car thought the DPF was not full, but in actual fact it was completely blocked.

All in all - a car that was already fairly quick is now quicker. My best 0-100kph before the tune was 5.6 seconds and after the tune i can get between 5.0 and 5.1 for the 0-100kph dash.

[Lucas_R]

I have been looking into tightening up the "driveline slop" this car has, in particular the rough gear change from 1st to 2nd which I believe is caused by soft transmission and rear diff mounts which are full of voids that allow a lot of movement. There is also some feedback movement from the driveline on deceleration from 3rd to 2nd. All the SQ5's we test drove did a similar thing so it's not a problem with our car as such, just the way they are designed.

I purchased a 034 Motorsports transmission mount and rear diff carrier mounts. I believe it will be the rear diff carrier mounts that will make the biggest difference, but will report back once the parts arrive and i can install them and test the difference.

034Motorsports rear differential cradle inserts were installed and they have made a considerable difference in reducing the drive line "slop" that these cars have from factory. Very happy with this little mod, and best of all it was a super easy and quick install and totally reversible. Anyone with a B8 series A4/S4/A5/S5//Q5/SQ5 etc should install these.

Also recently purchased and installed some Spulen (15mm front and 20mm rear) wheel spacers and new bolts from USP Motorsports which give the car a much nicer stance on the road and push the wheels out. SPULEN Audi Q5/SQ5 Flush Kit - WSKT-Q5F - 6928

[Lucas_R]

P2006 Intake manifold runner control stuck closed bank 1.

Upon Googling, i can see this type of error is pretty common on the single turbo 3.0T V6 TDI engine in the normal Q5/A6 etc, but have not been able to find any information relating to the bi-turbo engine used in the SQ5 (and several other Audi models such as the A6). The inlet manifold design is also different on these 2 engines.

I cleared the error code to see if it was a one-off or if it would come back again, and it came back again the following day.

So I decided to pull off some intake bits and see what i was dealing with - to my surprise the intake pipe, throttle plate assembly and intake manifold (all located after where the EGR is plumbed into the intake) had a thick layer of soot/carbon junk on them....no wonder I was getting the error!!!

I knew this was an issue with modern diesel engines and emissions targets but wasn't aware it would be this bad with only 35,000km.

Anyway, with a combination of petrol, degreaser spray and a soft wire brush these parts are looking much cleaner and the error has not re-appeared.....yet.

I have since purchased a can of Liqui-Moly diesel intake cleaner which i will run through the engine sometime this week. I am also going to look into the possibility of an EGR delete (either physical or ECU coded delete) to stop this from happening again.

UPDATE Jan 2024: After doing this intake clean several more times over the past few years, the best product I have found is regular carby cleaner like this Pro-Strength Throttle Body & Carby Cleaner (CARB400) All the other products (petrol/degreaser/Liqui Moly intake decarb etc) do basically nothing to break down the carbon. The carby cleaner is quite effective though.



Before:








After (not perfect but much better). I also cleaned the plastic pipe leading to the inlet manifold and scrapped out the inlet manifold as best i could but didn't take pics as my hands were pretty grotty by then:

[Fergs]

Hi Lucas,
i have an sq5 too and had to do this intake clean twice so far - i was thinking of adding the same catch can setup but do you think this issue is more around the egr system? did you end up doing the EGR delete - if so would love to hear what the result was -

cheers
Chris

[Lucas_R]

Hi Lucas,
i have an sq5 too and had to do this intake clean twice so far - i was thinking of adding the same catch can setup but do you think this issue is more around the egr system? did you end up doing the EGR delete - if so would love to hear what the result was -

cheers
Chris

Hi Chris,
The EGR delete attempt (software change and EGR block off plate) was a complete failure, as it stopped the car from doing a DPF regeneration (which it does every 400-500km) and several thousand km’s later my car went into a soft limp mode, shortly followed by a full on limp mode. Mechanic couldnt force a DPF regen, so I took the DPF’s off and back-flushed them with chemicals and high pressure water to clean them out.

Then flashed the software back to standard, and using VCDS software had to reset all of the DPF information in the cars brain so that it thought the DPF’s had been replaced.

Massive massive stuff around - don’t recommend it. Upon further investigation, both the EGR and DPF need to be blocked off/removed together at the same time along with software updates. You cannot successfully just delete the EGR.

So, long story.....sorry, but my car still has the EGR and DPF fitted and operational.

And yes I do believe the EGR is responsible for most of the intake buildup, with the remainder coming from blowby in the PCV system.

My plan is to just keep cleaning the intake every 6 months before an oil change to try and keep any buildup to a minimum.