oxleys11

Hi there, I wonder if anyone can help...

My 2004 A4 (2.0l petrol) has started making a nasty nocking noise on cold startup, it only makes the noise for about 1-2 seconds, and then goes completely, and sounds fine driving/starting from warm. The garage wants me to leave the car with them so they can hear it from cold in the morning, and ive shown them the video, but I get the feeling they are going to want to start taking things apart before they can diagnose... which might actually be the only way!?
Oil checked and although on the low side, its 'ok'.

Here's the vid..
any suggestions/clues would be really appreciated!

ps. I'm aware the breather pipe is broken, its on the list to replace!

lyleswk

If it were a 1.8, I would say cam adjustor. Assume the 2.0 has the same type system? The link is one that is in worse shape than yours. yours will get to that point if you let it go.


P.S. Your breather line is broken.

oxleys11

does sound like that... so why does it not do it all the time? and that vid said when hot and idle, mine seems to do it when cold and only on starting.


so, on this basis...

how poor am I going to be after paying to fix it?
is it possible for a fairly competent diy'er to have a go?

...or are special tools required?

and is it safe to keep using the car, or is belt at risk?


thanks!

PS. the breather is broken!? Lol.

lyleswk

Never read anything firm that explains why it makes noise when hot on some and on startup on others. Suppositions are when hot, it is simply worn out. When cold, it may not be getting oil pressure. So make sure you are using spec oil and changing often. I will tell you that I had mine replaced a year ago, it made noise when warm.

As far as using the car with the issue, it's okay for a while, but would address it easily in the next 2 or 3 weeks.

In my humble opinion, a medium to medium hard task (see attached). I would tackle if I had plenty of time to do the job and was not rushed by other activities. Just as a note, I have done some fairly diffcult jobs including 6 timing belts on 3 different cars cars, a clutch.

http://www.passatworld.com/forums/61...tensioner.html

P.S. Your breather hose is busted

oxleys11

Hmmm, I hate cars.

I only recently changed the valve cover gasket, at that gave me a headache... all good until things go slightly wrong, then I just want to see the whole thing fall off a cliff! Think this might be a step too far for me, especially with the timing concerns.

Whats really annoying... I was just about to advertise the car for sale, not so easy to sell now!

It does say at the end of that 'how to'.. "Start the car. The tensioner will make noise until it fills with oil.", which is what mine seems to be doing... and still doing after topping up the oil. It was serviced fairly recently, I wonder if another oil change could make a difference!?

or is this all wishful thinking!?

It is 'techincally' due a belt change, only done 45k since the last, but 5 years ago. I wonder if I'm going to have to bite the bullet and get all this done before selling it. £££££'s...

lyleswk

If you struggled with a valve cover gasket, I would not attempt.

But, let's go down theother path you started. When it was serviced, do you know what oil was used? It needs to be one from the attached list. If not, I would change the oil and see if that cures. Below is a link to the Audi Spec 502.00 which I assume is the same spec for your 2.0, but double check. Make sure you get down to page 3 - 5 and pick your favorite.

http://www.google.com/url?sa=t&rct=j...XhVueqv2Pqai1w

oxleys11

Hmmm, it will have been done at one of the local garages (not audi), I wonder if I call them and ask... but the chances are they wont be able to tell me.

Do you really think it 'could' be as simple as the wrong oil, and would it not have caused this issue since the service... which will have been a few months back.

Its a nice thought! and does seem a bit odd that the noise is only on startup, not when 'running'.

Thanks for your time by the way, it probably would have cost be hundreds to just get to this point at a local garage.

oxleys11

lots of people with exactly the same issue here, and they have tried oil/tensioner change, among other things, without success, unfortunately no answer... http://www.audizine.com/forum/showth...olution/page2?

ahhhhhh!

oxleys11

and same again here...
http://www.audiforums.com/forum/b6-m...rattle-179042/

with this... (surely there must be a fix!? I really dont feel comfortable selling the car to someone, only for them to hear this noise the next morning!)


Technical Service Bulletin Transaction No.: 2010294/5

Rattle/knocking noise from camshaft adjuster at engine start

Release date: Nov 21, 2008

Technical Background

The camshaft adjustment is hydraulically actuated and controlled by the engine oil pressure. If the engine has been turned off for a long time, the oil pressure drops down and the oil partially flows back into the oil sump.

To ensure an efficient camshaft adjustment right after an engine cold start, the oil pressure inside the camshaft adjusters must be built up as fast as possible. During this time, a rattle or knocking noise may be noticeable.

This noise is normal at engine start and will last until the oil pressure is fully built up, which takes about 1-2 seconds.

Production Solution

Not applicable.

Service

Do not replace the Camshaft Tensioner(s) or Camshaft Adjuster(s) for a noise concern as described above.

Replacing the Camshaft Tensioner(s) or Camshaft Adjuster(s) will not eliminate this noise.

lyleswk

Exactly why I had the caution in the first post about the different engines. Looks like you have a good answer from AZ.