engine sound

[snow6]

Hey ,
My 2000 Audi A6 2.8L statrted to make the noise recently. Any ideas what it causing it ? thanks a lot.
http://youtu.be/NCyg4ietV6U

[Calimus]

Sounds like it could be the cam chains caused by a problem with the cam chain tensioner.

[snow6]

Thanks for the reply.
I have been looking for this in forums. So here are some more points :

- This happens only after engine warms up.
- Started to happen after an oil and oil filter change. I have used mobil1 0w-40 full synthetic oil and a mobil 1 oil filter. I am not sure how it was with the previous owner since I got it 9 months ago.

People say this might be
- a sludge problem
- or cam tensioner problem.

As I said it does not do it at cold start it works fine until it warms up.

Thanks again for any kind of input.

[Vinchenzo51]

Sounds like my lightweight flywheel chatter lol

Happens when it warms up is odd... I would have thought the opposite, oil was having trouble getting to the top of the engine and causing the noise, but it seems the issue happens WHEN the oil gets up top. Weird

[Calimus]

Some issues can result at low oil pressure when warm. In early VW 16v engines, warn intermediate shaft bearings will cause low oil pressure once the oil gets good and hot. In this case, I don't know the engine well enough yet to try and pin point the issue.

And so as not to thread jack, Vinny, I'm curious about your LWFW chatter. I supposedly have a LWFW in my car as well from the PO and it certainly makes some interesting noises. Could you PM me with a little more info, I'd like to go over that with ya a bit if you don't mind?

[snow6]

Hi,
Thanks a lot for the suggestions. I have not been using the car for a since I was busy did not get anything done on it yet. I wanted to give a try again today. So, initially when cold and after engine become hot it sounded normal. However after I drove about 4 miles (in city) it started sound like Diesel again. I was planning to do the water spraying thing on the belts but it was raining a lot today and left it for tomorrow since I do not have a garage.
So, if it was the cam chain tensioner , wouldn't that be there all the time? Why does it show up some time after the engine gets hot? I will probably take the car to mechanic on Monday but would be nice to get some more advices before I pay tons of $$$.

Thanks again!

[Calimus]

Oil pressure is higher when the engine is cold. If the tensioner is faulty (it uses oil pressure and springs to create the tension) then there is enough pressure when cold, but as the oil warms up and the pressure falls into normal levels, the tensioner will start to slack and that can create all the noise as the chain will develop slack and can lash at the valve covers and other things around it.

[snow6]

it turned out to be a loose timing belt.I have the timing belt changed and the sound is gone.
thanks for the replies.

[matthilaman]

glad you caught that tbelt when you did!