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Q5 FSI Carbon Build-up
08-30-2014, 09:44 PM
#291
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I had it come back. The cleaning does not fix the Cause of the carbon build up; just cleaning up the effect of burning oil. My A4 was cleaned and it was burning oil right away. Then they did the full engine overhaul/pistons and it still burned oil after 12k more miles. Dumped the car after that. I keeping hearing that the 2013 and on have a fix and this should not be happening.
What really makes me upset is why my 2012 Honda Accord with Honda's first direct injection engine can easily go 10,000 miles without burning almost no oil!! How do they have this figured out while the Audi engineers are just now coming up with possible solutions.
What really makes me upset is why my 2012 Honda Accord with Honda's first direct injection engine can easily go 10,000 miles without burning almost no oil!! How do they have this figured out while the Audi engineers are just now coming up with possible solutions.
Last edited by Hockeymonkey; 08-30-2014 at 09:52 PM.
09-02-2014, 06:24 AM
#292
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My Q5:
- 2010 Q5 3.2 FSI, 34k, picked up in June 2009
- Maintained by Audi (Audi care)
- Fuel - 99% of the time Shell 91 octane
- Typically drive around the city plus some highway - in S mode at times
Issues:
- Rough idling/shudder about 2 months ago
- 2-3 tries before the car would start (usually twice a week). Over the last 3 weeks.
- Check engine light on for about a day (2 days ago)
So of course I came to the AudiWorld and other Audi forums (the Audi community is awesome ) which led me to believe this might be a carbon buildup problem based on the symptoms. I took it to my Audi dealer yesterday (Toronto area) and they confirmed that this is a carbon buildup problem. They'll be keeping my car for a few days and replacing the injectors under warranty - very decent dealer btw, always look into and fix any issues I bring to them - of course it helps that I'm always right
For those interested here's a summary of the information I've collected....
Issue - Direct injection engines such as FSI get carbon buildup on the valves and injectors because there is no fuel passing over them as it does for other engine designs - so no cleaning. This leads to misfires, loss of HP (substantial) and potentially other issues for the engine.
Turbo engines - 3.0 T (supercharged) and 2.0T seem to suffer a lot less from the carbon buildup issue, possibly due to higher engine temps in the manifold which burns off the carbon deposits.
What doesn't seem to work to prevent this:
- Catch cans don't have much effect (don't know the technical details are but something to do with the "gunk" coming out of the engine which isn't prevented by the catch can)
- Frequent oil changes
- Fuel additives (the additives never make it out to the valves so they have no effect)
What may work:
- Always using approved gas (top tier with detergents - not really convinced on what impact this would have...maybe burning cleaner so less deposits making it out to the valves)
- DIY cleaning agents for valves (probably shouldn't try this unless you know a lot about cars - I don't)
- Driving for a long distance (highway) once or twice a week - perhaps also combined with higher revs for a limited time 3000 - 40000rpms or so (to burn off deposits)
- Spirited driving (to burn off deposits)
Warranty and other stuff:
- Most decent dealers will clean/replace under warranty once there is a check engine light and error code confirms (there might not always be a check engine light). Might want to make sure the error code wasn't simply turned off.
- Audi doesn't seem to be doing anything in terms of adding this to maintenance probably due to the amount of time it takes; dealer told me half day's worth of effort. This is quite sad and unreasonable as we as customers who purchase these luxury products should be entitled to having these products work...seems basic to me.
- Out of warranty you're looking at about $500+ every 3 years or so. Audi should step up and extend the warranty for this issue, likely though they're probably waiting for a class action.
- For dealers who try to ignore you I suggest you tap into the great wealth of knowledge available in this forum and others so you can challenge your dealer. Persistence is also a great technique....
So that's it...if you have an FSI engine you will eventually get carbon buildup and possibly have to dish out some $$$. As for me I've ordered an S5 with a 4.2 V8 FSI (new S5 with 3.0T is just too ugly) which should be arriving this Christmas....maybe I can get a discount on the valve cleaning with two FSI engines I'm an optimist....seriously though I will be writing a letter to Audi NA....this is so not cool Audi, clean up your act.
- 2010 Q5 3.2 FSI, 34k, picked up in June 2009
- Maintained by Audi (Audi care)
- Fuel - 99% of the time Shell 91 octane
- Typically drive around the city plus some highway - in S mode at times
Issues:
- Rough idling/shudder about 2 months ago
- 2-3 tries before the car would start (usually twice a week). Over the last 3 weeks.
- Check engine light on for about a day (2 days ago)
So of course I came to the AudiWorld and other Audi forums (the Audi community is awesome
) which led me to believe this might be a carbon buildup problem based on the symptoms. I took it to my Audi dealer yesterday (Toronto area) and they confirmed that this is a carbon buildup problem. They'll be keeping my car for a few days and replacing the injectors under warranty - very decent dealer btw, always look into and fix any issues I bring to them - of course it helps that I'm always right For those interested here's a summary of the information I've collected....
Issue - Direct injection engines such as FSI get carbon buildup on the valves and injectors because there is no fuel passing over them as it does for other engine designs - so no cleaning. This leads to misfires, loss of HP (substantial) and potentially other issues for the engine.
Turbo engines - 3.0 T (supercharged) and 2.0T seem to suffer a lot less from the carbon buildup issue, possibly due to higher engine temps in the manifold which burns off the carbon deposits.
What doesn't seem to work to prevent this:
- Catch cans don't have much effect (don't know the technical details are but something to do with the "gunk" coming out of the engine which isn't prevented by the catch can)
- Frequent oil changes
- Fuel additives (the additives never make it out to the valves so they have no effect)
What may work:
- Always using approved gas (top tier with detergents - not really convinced on what impact this would have...maybe burning cleaner so less deposits making it out to the valves)
- DIY cleaning agents for valves (probably shouldn't try this unless you know a lot about cars - I don't)
- Driving for a long distance (highway) once or twice a week - perhaps also combined with higher revs for a limited time 3000 - 40000rpms or so (to burn off deposits)
- Spirited driving (to burn off deposits)
Warranty and other stuff:
- Most decent dealers will clean/replace under warranty once there is a check engine light and error code confirms (there might not always be a check engine light). Might want to make sure the error code wasn't simply turned off.
- Audi doesn't seem to be doing anything in terms of adding this to maintenance probably due to the amount of time it takes; dealer told me half day's worth of effort. This is quite sad and unreasonable as we as customers who purchase these luxury products should be entitled to having these products work...seems basic to me.
- Out of warranty you're looking at about $500+ every 3 years or so. Audi should step up and extend the warranty for this issue, likely though they're probably waiting for a class action.
- For dealers who try to ignore you I suggest you tap into the great wealth of knowledge available in this forum and others so you can challenge your dealer. Persistence is also a great technique....
So that's it...if you have an FSI engine you will eventually get carbon buildup and possibly have to dish out some $$$. As for me I've ordered an S5 with a 4.2 V8 FSI (new S5 with 3.0T is just too ugly) which should be arriving this Christmas....maybe I can get a discount on the valve cleaning with two FSI engines
I'm an optimist....seriously though I will be writing a letter to Audi NA....this is so not cool Audi, clean up your act.
09-02-2014, 07:56 AM
#293
I was reviewing as much as this thread as possible and was trying to better understand if this impacts all Q5s or if the TDI is not part of this issue?
09-02-2014, 08:15 AM
#294
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3.2 is the engine with the issue. Older 3.0Ts also had some carbon issues, but it was addressed before the Q5 got it. 2.0T and TDI don't have the issue.
09-02-2014, 08:17 AM
#295
AudiWorld Expert
09-02-2014, 08:32 AM
#296
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I don't remember any specifics, and I don't recall the 3.0T being as much of a problem as the 3.2, just that there were some issues that people had with the earliest revision of the engine, when it was only available in things like the S4. Seem to recall people talking about it having been addressed in a newer revision of the engine that the facelift vehicles have, so it'd be 2010-2012 3.0Ts that would potentially be an issue and 2013+ should be more of a "normal" level of risk.
10-19-2014, 02:25 PM
#298
Thx for your insights on CB
Have any of you tried to tackle the CB by reducing the quality of exhaust being recycled back to engine as part of EGR? I wonder if there maybe a device that can filter the oil and gunk before it gets back to engine.
Any thoughts on what can be done with PCV valve to again avoid/reduce CB
Finally, any experience on how susceptible TDI engines are to CB?
Thx
Have any of you tried to tackle the CB by reducing the quality of exhaust being recycled back to engine as part of EGR? I wonder if there maybe a device that can filter the oil and gunk before it gets back to engine.
Any thoughts on what can be done with PCV valve to again avoid/reduce CB
Finally, any experience on how susceptible TDI engines are to CB?
Thx
10-21-2014, 09:00 AM
#299
AudiWorld Member
Just an update as it has been a while. My 2010 3.2 Q5 now has 148,000 miles. Still have not experienced the carbon buildup. I only use top tier gas, and it is mostly highway miles. I do give it an "italian tuneup" every once in a while. (IE: Drive it like you stole it to heat everything up real good).
10-28-2014, 09:40 AM
#300
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09 q5 84,000 miles P0491
Anyone who can help. 09 q5 3.2, MIL came on Sunday morning, pulled code at a local auto parts store and came up with the dreaded p0491. I am at the Audi dealership as we speak, I have done several hours of research and worried it is carbon buildup. Audi stated it is under warranty but have to diagnose it for themselves, which I totally understand. My question is this, I only have one code, p0491 and not p0492. Could the generic reader only have pulled one or could this problem be something different that "worse case" where they have to pull the engine. Just want to be educated before I hand over the keys.