Various mechanics diagnosing 2 problems differently
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AudiWorld Junior Member
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Various mechanics diagnosing 2 problems differently
2015 Q5 3.0T Prestige - 152k miles
A few months ago I got a code P0491 - Insufficient air flow at secondary air system bank 2.
Around the same time my oil consumption started to go up.
I had researched the P0491 and found a good bit of stuff related to there being carbon buildup in the secondary air ports. This YouTube mechanic says he works on lots of Audi’s and with the 3.0T it’s ALWAYS the carbon buildup in secondary air ports when you get that code. (Videos in this thread https://www.audiworld.com/forums/q5-...k-2-a-3072048/ )
I take it to MECHANIC #1 (my normal guy who does my oil and fluids and brakes etc) - he says the code is from faulty Secondary air pump. He says oil leak is main seal leak and bad VCG.
He replaces the secondary air pump, but not clean carbon buildup. (Didn’t have time to do VCG that day, he told me not to mess with main seal)
He resets the code and CEL stays out for 2 days then comes back on.
Oil consumption seems to go way down after this visit.
MECHANIC #2 does a diagnosis and says the oil leak and code are related. He says it’s the oil separator. He also says he pulled a code for a bad camshaft sensor solenoid. He agrees VCG needs changing but says no main seal leak.
He resets code and CEL light goes out and stays out for 2-3 days, comes back on for 2-3 days and then goes back out and is out now.
MECHANIC #3 - I will take it to this week I described it over the phone (this guy I know is good, a little expensive but I do believe he’s most likely the most expert out of the mechanics) said the code ‘could be the emissions system’…
”Emissions’ made me say - oh the O2 sensors are 150k miles old could that do it?
I’m just flustered bc Mechanics 1 & 2 & YouTube mechanic are all describing expensive repairs but who knows who is right and who is wrong…. Mechanic 2 made me think he wouldn’t even mess with it .. like I could just drive it considering the age, mileage, cost of repair maybe not worth it?
It drives fine…power fine, fuel economy fine…
A few months ago I got a code P0491 - Insufficient air flow at secondary air system bank 2.
Around the same time my oil consumption started to go up.
I had researched the P0491 and found a good bit of stuff related to there being carbon buildup in the secondary air ports. This YouTube mechanic says he works on lots of Audi’s and with the 3.0T it’s ALWAYS the carbon buildup in secondary air ports when you get that code. (Videos in this thread https://www.audiworld.com/forums/q5-...k-2-a-3072048/ )
I take it to MECHANIC #1 (my normal guy who does my oil and fluids and brakes etc) - he says the code is from faulty Secondary air pump. He says oil leak is main seal leak and bad VCG.
He replaces the secondary air pump, but not clean carbon buildup. (Didn’t have time to do VCG that day, he told me not to mess with main seal)
He resets the code and CEL stays out for 2 days then comes back on.
Oil consumption seems to go way down after this visit.
MECHANIC #2 does a diagnosis and says the oil leak and code are related. He says it’s the oil separator. He also says he pulled a code for a bad camshaft sensor solenoid. He agrees VCG needs changing but says no main seal leak.
He resets code and CEL light goes out and stays out for 2-3 days, comes back on for 2-3 days and then goes back out and is out now.
MECHANIC #3 - I will take it to this week I described it over the phone (this guy I know is good, a little expensive but I do believe he’s most likely the most expert out of the mechanics) said the code ‘could be the emissions system’…
”Emissions’ made me say - oh the O2 sensors are 150k miles old could that do it?
I’m just flustered bc Mechanics 1 & 2 & YouTube mechanic are all describing expensive repairs but who knows who is right and who is wrong…. Mechanic 2 made me think he wouldn’t even mess with it .. like I could just drive it considering the age, mileage, cost of repair maybe not worth it?
It drives fine…power fine, fuel economy fine…
Last edited by Rltrdc; Sep 15, 2024 at 10:03 AM.
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