3.0 Carbon Cleaning??

[Pat Dolan]

Wife's Q7 TDI still under extended Dieselgate warranty (4 years left to go) but in for its last free oil change/service couple weeks ago. Shop found oil leak around the filter mounting, so offered to rip it apart under warranty and fix the leak. They also offered to blast clean carbon deposits while it was apart for $450 Cdn. This is not a DI gasser so could not imagine intake ports being carboned up, but I also have not worked with ANY of the 6 cylinder EGR system diesels. Anyone know the likely carbon location and status?

 

[PeterA1]

Carbon and soot really likes to build up in the intake because of the egr coming from before the dpf. I took my intake off and it was completely packed full of soot, and I was able to just replace it rather than clean it and it significantly improved my mileage. I think it was about $500us for the new intake and I might get my old one cleaned and sell it on here once I have time. I'd recommend the cleaning if it's bad, it should only be a few bolts to just take a look at it.

 

[danmin]

Wife's Q7 TDI still under extended Dieselgate warranty (4 years left to go) but in for its last free oil change/service couple weeks ago. Shop found oil leak around the filter mounting, so offered to rip it apart under warranty and fix the leak. They also offered to blast clean carbon deposits while it was apart for $450 Cdn. This is not a DI gasser so could not imagine intake ports being carboned up, but I also have not worked with ANY of the 6 cylinder EGR system diesels. Anyone know the likely carbon location and status?

not sure how many miles it has but i can promise you it has more carbon in the intake and on the valves than you could imagine. I had my oil cooler replaced and the whole “vee” resealed. including an intake cleaning. 30k miles later and everything is covered in soot and sludge again. a significant layer of it

 

[Pat Dolan]

not sure how many miles it has but i can promise you it has more carbon in the intake and on the valves than you could imagine. I had my oil cooler replaced and the whole “vee” resealed. including an intake cleaning. 30k miles later and everything is covered in soot and sludge again. a significant layer of it

Gosh, I completely missed one of the most important bits of information. Just coming up on 80,000 kms. Because of warranty, I will probably not deox anything at least until 2028.

Any idea what driving conditions contribute most o buildup?

 

[MrCypherr]

I've compared a non-deleted vs deleted 3.0L, and the intake valves, manifold, etc is so much cleaner its insane especially after 40,000kms.

 

[danmin]

Gosh, I completely missed one of the most important bits of information. Just coming up on 80,000 kms. Because of warranty, I will probably not deox anything at least until 2028.

Any idea what driving conditions contribute most o buildup?

Your egr is on about half the time you idle after warmed up. Your egr is on until you’re warmed up unless you’re above say 2500 rpm. EGR kicks on intermittently whenever you maintain speed at part throttle to reduce emissions. EGR is disabled on full throttle. I wouldn’t even consider “Dynamic EGR”. People in the far north drove cars for many years without any form of EGR. Delete it. or tune it completely out at the very least.

your specific car will differ, but this is the general tendencies of EGR systems

 

[Pat Dolan]

Is there a digital only delete option that I can use to sail through next 4 years of warranty? I will be doing all maintenance from now on, but if it needs repair to anything related to emissions (and that means just about anything at all) need to be able to restore stock programming without trace. I long ago did mechanical delete on my ALH but it is a far simpler (and I suspect more reliable and predictable) machine,

 

[danmin]

Is there a digital only delete option that I can use to sail through next 4 years of warranty? I will be doing all maintenance from now on, but if it needs repair to anything related to emissions (and that means just about anything at all) need to be able to restore stock programming without trace. I long ago did mechanical delete on my ALH but it is a far simpler (and I suspect more reliable and predictable) machine,

Oakes tuning

 

[MrCypherr]

Is there a digital only delete option that I can use to sail through next 4 years of warranty? I will be doing all maintenance from now on, but if it needs repair to anything related to emissions (and that means just about anything at all) need to be able to restore stock programming without trace. I long ago did mechanical delete on my ALH but it is a far simpler (and I suspect more reliable and predictable) machine,

Just so you are aware, VW can see if the ECU has been reflashed and how many times. People say this is a myth but it has been confirmed that its true.