ronrevere

Hi All, I have a 2012 A6 3.0L with about 40k miles on it. On most cold starts, I get a loud tapping noise for about 4 seconds. Sounds like the valves not getting oil. This was the diagnosis from the dealer who stated that this was normal. My concerns are:

How can such a loud metal on metal clanking not be bad for the engine?
Why don't I don't hear this on similar Audi's?
When I start the car in a parking lot, how do I get people to stop staring?
When I go to sell the car, how do I get someone to buy this story?

I lost an engine on my 2005 3.2L because of a failed Timing Tensioner. This noise reminds me of that.

Check it out. What do you think?

Kris Hansen

That doesn't sound normal.. it also doesn't really sound like lifter chatter either.. What I'd do is try to actually pinpoint where the sound is coming from in the engine. Have someone else start it, and see if the sound is coming from the front, top, or rear of the engine.

Also, I assume you have plenty of the correct weight oil, and OEM filters and such?

ronrevere

Thanks for the input Kris. All ok with oil & filter. Just changed recently.

A6 Session

I know this is an old post, but if anyone has the same sound - as do I - could be what I've been told. I only hear it if the car has been sitting for 2-3 days without being started. It could just be from the fuel injectors. Loss of fuel pressure in the lines during an extended off time, and the pressure just building up. Goes away in about 1 second as in your recording. I also agree - doesn't sound like the valve train.

SpectreGadget

I have a 2012 A7 that makes this same sound on cold start and wondering. Anyone know what this can be?

Prospeeder

I too have heard its a noise associated with the direct injection during first startup as it builds up pressure.

J_Win

I noticed the same thing on early morning start ups, slight rattle. I just hit 60k miles on my 2013 A7.

LexusLSguy

Cold starts is when most engine wear happens. Cold start rattling means is even more of an issue. I would first do an engine flush right before your next oil change. I personally use Liqui Molly's Mos2 product as well as their synthetic oil. I have never had any cold start noises and have 64k on my 3.0 Often this problem is exacerbated by extended oil changes that cause carbon buildup in the engine. 10k oil changes is not such a good thing.

RKsilver

Sry guys.. that's a timing chain rattle.

AudiAllTheWay

^ Agreed ^

I have studied and worked on Audi 3.0T fuel system and that noise is not direct fuel injection system related. Sounds like a chain tensioner compensating for a broken guide. Idle will drop and be rough due to loss of crankcase seal but try pulling oil fill cap and listen in opening while engine is started... it may be really loud!