OLI77

The Audi I recently purchased is a 2L turbo with 60k miles. Its a 2015 so I assume driven on the highway a lot. When I got it from CarMax, the average speed on the 59K miles driven so far (computer long-term storage) was mid 40s mph, and the front of the front of the car is nicely peppered with rock chips from the hood throughout the front of the car. So this makes me think highway car.

It is butter smooth on everything but here is the question. On every cold start a pump that is noisy kicks on while it idles at ~1200 rpm. Because it is warm in KY right now, I assume this is some sort of pump that helps with the initial startup as in a secondary air pump on the e46, or is it a turbo thing?

Question 2, during that initial ~ 1 min startup period when that pump is on, the car almost misfires, burbles a little bit and I can feel engine shakes, some form of uneveness somewhere, totally engine related. As soon as the pump turns off, idles to 800 rpm butter smooth and is smooth engine-wise throughout the powerband for the rest of any drive. Is that normal in a turbo or is this a sign of something that is wrong.

No codes, everything is A OK according to Audi.

Appreciate your knowledgeable comments.

OLI77

No love?

Changed the plugs and that did not fix the slightly funky idle on cold start. Will run some techron cleaner in the gas tank.

I read an another thread/ forum that some intake solenoid phase changer might be the culprit. Am I using the right word? Do we have that in the A6 (2L)?

Mesquite77

Don't panic, mine at 58K, mostly highway runs a little rough for first minute, then is perfect. It idles initially at 1,200 or so, and smells a little rich, but then is sublime. I've had it since new, and there is nothing at all wrong with it. Uses no oil, no codes, I wouldn't worry about it.

OLI77

Boom. Case closed,
Thanks for the love from Texas!

Good, I will stay the course and maintain as best I can. Car is smooth.

Dougrey

OLI77

Doug, now you make me worry about this again. Should I stay or should I go? Is it real or is it Memorex? Dirty intake valves?
I think I will monitor this for a while. I don't feel too comfy doing this on my own and I do not have a compressor, I would have to pay someone to take care of it.
I will search leisurely for a place locally or wait for it to throw a code.
Thanks for the input.

Dougrey

It's not Memorex....

All direct injection only engines have this problem. Think of it in the same light as replacing the timing belt for rubber-band engines...It's normal maintenance. The job is not difficult. Hopefully you can find an independent shop that is set-up to walnut blast. Shouldn't cost more than $400.

McFuzz

You have a variant of the 2.0 TFSI motor in your car, also known as the TSI motor in VWs. They do have a secondary air pump that kicks in on cold idle and lasts for a brief period of time - thus they clattery/diesely sound

OLI77

Thanks McFuzz, I always feel this unevenness in the engine on a cold start. I called a shop in Cincinnati that takes care of VW and Audis and they quoted me ~$900 for a walnut shell intake blast and some injection port rings or seals.
The secondary air pump is definitely timed perfectly with those engine "burbles" which disappear when RPMs drop. . . Time will tell I guess.

McFuzz

Re-read your original post as I didn't notice the misfiring statement. That is most definitely unusual. Do any idiot lights come up? Sounds like maybe the pump has such a high electrical draw that the alt can't cope with everything?

The only other thing I can think of is carbon build-up around the intake valves - but that normally occurs close to 60-70K miles and you'd notice it across the entire powerband, not just cold idle...