Audi A6 2.7 & 3.0 TDi EGR & Intake system cleaning info please...

[gupsterg]

Hi peeps ...

Recently been going over data and found this in my photo library from when I changed my throttle body...



Above is the throttle body adapter which connect to the top section of the intake system on engine...

I don't know why I never took note of above photo before ...



The red line is the throttle body which was replaced and camera shot is from that view point...

The yellow diamond is roughly the location of the clogged holes... yellow line is the EGR gas flow, blue lines when going through EGR cooler...

Cleaning throttle body adapter manually seems very doable easily as does the EGR pipe going to EGR valve (ref the the dome like thing for non mech.viewers like me )...

I'm tempted to change EGR valve instead of cleaning (£80) and the EGR control flap & vacuum unit (£60)... the two reasons are firstly for speedier swapout, secondly the vacuum elements to these parts would be new...

I've found a used EGR cooler reasonably priced on ebay which I could clean before hand to speed up swap over...

Now that leaves the rest of the intake system the black upper/lower section... instead of removing I'm thinking Terraclean Or Link:- Diesel Intake System Cleaning
Near the latter part of this video I was amazed at the smoke ...

In the past additives have never helped me but I keep an open mind and new products are always available...

I may just do manual clean of throttle adapter and replace EGR systems parts and find and don't need to go further... ie the chemical cleaners above to clean rest of intake system...

The chemical cleaners seem so enticing as you think no part removal...

But last time when I cleaned my old throttle body I found that some of the carbon just wiped off and some was so stubborn that had to use a screwdriver to etch/scratch off ...



Above throttle was the original from factory IMO as date code 01/08/05 on it... above throttle body was replaced with new ...

Any advice on chemicals for manual cleaning of EGR system? any people (besides JimC64) who have also had Terraclean/BG treatment?

[gupsterg]

Hurrah hurrah! My idle MVB for EGR is finally in spec vs actual ...

Soon lots of photos & videos... and the usual massive posts ...

[gupsterg]

Now what did the man say:-

None at the min just need to confirm if the egr side is ok, this is part when vas pc is far more powerful than vcds

So if the throttle valve is now resolved the next step i would take is to reduce the egr flow at the intake on the throttle valve by using a blanking gasket or reducing the diameter of the port hole

This will reduce the flow and again you could test it or check the egr is order (I think its leaking through when it should be off) or back to the worn injectors poor spray/dribble

Rule egr out firstly

You don't have to keep thanking me, its flattering but its hardly a glamorous job fixing cars more like a prison sentence lol

It may not be glam mate but I am really very very thankful for your posts! everywhere ...

And I'm sorry A8 Tech & Crasher for the even more massive PM's compared to my posts... they may soon get shorter ...

I'm really pooped tonight I've spent nearly 3 nights going over TSB/TPI's, photos of my blinking engine bay...

So tomorrow will be when normal postal service resumes ...

I think tonight shower, nice few shots of single malt & bed ...

[gupsterg]

*** WARNING IMAGES MAYBE DISTURBING TO VIEWERS ***

Upper manifold Bank 1 ...



Lower manifold Bank 1...



Upper manifold Bank 2...



Lower manifold Bank 2...



*** WARNING LIVE VIDEO ACTION MAYBE DISTURBING TO VIEWERS ***



*** WARNING FURTHER IMAGES MAYBE DISTURBING TO VIEWERS ***

Upper manifold throttle body adapter side (adapter removed)...



Zoom shot...



The throttle body adapter... please note the very constricted EGR gas ports...



Now I've had a few rants about what happened with my car when I went to Dialynx...

I know I do not have the reputation of Keith Murray... but I went with him because of his reputation...

I am self employed just like him... I chose to go with him because I thought he would do a good job...

But an epic fail viewers ... people may think I'm upset they are right!!

I write posts & photograph as a record of what I do to help myself & others...

I will soon be gathering all information to post a thread in the garage recommendations sections....

Now I asked when my engine was out of the car about cleaning the manifold/EGR

As you know Jim just had chain rattle fix done, plus some other bits, in process of making a thread about it..

I asked the workshop the viewpoint of decoking EGR system, as engine was out and easy access...

Mechanic replied "When I did chains on my A8 I took a lot of time to decoke EGR system I felt no difference in performance unless having issues would not do" he then proceeded to view engine port holes etc and said "your engine looks clean for age/mileage I would not go down this route" so I left it at that

So only a thought have car manufacturer's already assessed that for a extensive period these items do not need cleaning/maintenance... for instance there are guidelines of engine oil, gearbox oil and various filters etc but not EGR system... and yes we may agree/disagree with some/other manufacturer recommendations

Is the port size already designed to allow for coking ... so unless flaps or valve malfunction would decoke be unnecessary

Post from here Link:- A6 EGR location & removal "how to?" - Page 2

Other related posts to my Dialynx experience Link:- 1 2

You can see the advise above he gave ... If you ref the throttle body adapter image (last one above)...

He viewed that for me and since then and now I've done what 5-7k miles! It could never have built up to that state in those miles IMO and I'm not even of his professional skill!

I wish I'd looked then not now!

This is what Keith Murray ( Dialynx ) should have done for me...



I highlighted all the issues I thought I would like him to look at before booking, at booking...
I said please my car has been a problem not easy to spend £2k ish but please take time if we need to expand budget please just do right for me & let me know!

There's more to come so keep subscribed viewers !

[gupsterg]

The cleaning process ...

Step one scrape with screwdriver/tool... result below...



The mid clean video...



I also used my homemade tool from injector seat cleaning... to vacuum clean TBA...



Plus I used my mates air compressor to blast TBA... now the ports highlighted in red below... I used a 4mm2 elec wire bent as a hook to clean out any stubborn remnants...



Then I soaked a tea towel in diesel and cleaned bigger port on TBA... then I used a cable tie to feed cloth through EGR port...






2


I repeated steps as necessary to minimise chance of carbon passing with charge air to engine...

Early signs are looking good .... gonna weigh the carbon from the throttle body adapter... my guess it could fill a 250g to 500g marg pot easily...

Now I can see when A8 asked to constrict port it had no effect as EGR gas was not flowing any how...

After reading the SSP about the hot film air mass it had great analogy's on how air pressure is effected by temp...

The charge air was being cooled by the intercooler system, ECU thought EGR gas was flowing when air mass was connected as EGR system is enabled then... but due to carbon constrictions hotter EGR gas was not flowing to adjust the air mass... so air mass out...

When mass air was disconnected EGR system off ECU use other calculations so car run better/fine...

On the facelift (09-11) intercooling can also be adjusted with a control flap between the two intercoolers (ref SSP), on prefacelift there is none...

There maybe more work still gonna get vacuum gauge to test vacuum system on EGR valve & cooling flap...

There will diagrams on the channelling within throttle body adapter on the EGR port section soon...

[MFGF]

Good news Gup! Does this mean you no longer need a compression test? Is everything now fixed?

MF.

[gupsterg]

Honest answer yet fully don't know ... my version on Kites's signature "....If only I was as smart as this bloody car" ...

Car only been for few small journeys... after looking at other modules A8 is very right that the cars need time to settle... virtually all modules are constantly monitoring and adjusting things...

We may moan about design of cars but lot of this is due to how "We" want more power, better MPG, etc... laws want better emissions, etc...

All of these sensors, processes are to make it variable to factors like temperature, ageing of parts, etc and provide better power, more MPG, lower emissions, etc...

It has been such a mind opening and educational trip ....

[Cwizard]

Wow just saw this thread now. I can't believe how much carbon is stuck. You reckon driving it at its max speed (257km/h on speedo) would clean it out? These engines are made for German autobahns where the speed limit is... well there is no speed limit lol so it could actually cope with very high speeds. Driving it ever so slowly on other roads would eventually create clogging up problems? Sounds logical to me.

[gupsterg]

Wow just saw this thread now.

Hi ya mate ...

Sorry again... been so snowed... I'll PM about what been going on ...

I can't believe how much carbon is stuck. You reckon driving it at its max speed (257km/h on speedo) would clean it out? These engines are made for German autobahns where the speed limit is... well there is no speed limit lol so it could actually cope with very high speeds. Driving it ever so slowly on other roads would eventually create clogging up problems? Sounds logical to me.

First of all you really don't need to worry about the carbon in the top section of the manifold (the black pipe work), secondly you really don't need to worry about the carbon in the swirl manifolds (the lower black section)...

Please reference Sparkers() guide here Link:- Intake Manifold Replacement and Fix - 2.7 TDi + 3.0 TDi V6 Engines
(Sorry mate just gonna steal your pic )



So you can see most of the carbon gets stuck in the the top/lower section.... the engine IMO runs at such a high temp in the combustion chamber its not that bad down there...

Sorry Cwizard just gonna steal that great link (), viewers ref this thread to see some internals further down the engine... Link:- Audi A4 3.0 TDI catastrophic engine failure - TDIClub Forums

Now disregard the fluid/damage from the over heated glow plugs disintegrating and damaging the engine in above linked thread...

From what I could see carbon build up is from where the EGR enter onwards in the charge air system (air intake) the intercooler section will be fine (IMO)...

I never removed any carbon in the black top or lower section.... WHY?

Well all of that carbon has built up layer upon layer, it is not creating an issue, if I started removing it I would have needed to have been so careful that any carbon never ended up going further down the engine... or do full removal and very time consuming cleaning easier to buy and replace get new flaps, links, etc..

This stuff is very hard... I feel I would never wanna use a chemical to soften or remove it as would you really want chunks running through your engine? (again IMO)

I really had to take a screwdriver to the throttle body adapter, the ports were cleaned with another tool homemade from copper wire, will explain further when upload photos of that process ...

I will if things go to plan just swap out the complete lower manifold for new...

I've looked at getting a complete top section (used) from Germany, then at my leisure I can clean part and put on when do the lower section...

The main aim was to restore EGR gas flow which has been achieved ...

Idle mass air readings MVB very good now ... I have videos of before and after VCDS live diags, not yet got chance to edit and upload ...

Keep subscribed for more soon! ...

[sparker]

Hi Gup,

I had not looked at these posts until now, sounds like you maybe getting too the bottom of this problem, well done.

When I had the manifolds removed I had noticed the holes for the EGR in the throttle body where a bit blocked up with carbon and did clean those up. The old manifolds had no where near as much carbon build up on them as those in the pictures. I always clean any thing I see when doing a job, just as a preventative measure and had not even thought about saying anything in text as I didn't have any problems. Looks like they could be a problem area as the engines clock up the miles, so if this has fixed the revs then you could have found a simple, free fix for people try if they have similar symptoms.

If this is the answer then I am so pleased for you. New glow plugs and battery and then Gup take some rest and enjoy driving.

I look forward too hearing from you that Zesty is now Peach.