davek4300

Main question is an intermittent clicking/rattling noise from under/inside the intake manifold. More prominent when warm. During idle I rev up to about 2500/3000 clicking/rattling noise happens during rev up, as it revs back down you can hear the clicking/rattling again right as it goes back down below 1000 rpm. In addition there is a constant whining sounds that sounds like the timing belt is over tighten or the tensor(s) are too tight? Unless the pulleys or tensioners re are possibly the culprit..?

Currently have 195k miles on the 4.2, Timing belt was done by previous owner at 150k. Both noises seems to start a few weeks ago.

I’m taking it in to a few Independent shops this week, but looking for input….I’d really appreciate it. …Thanks

Florida8L

I would inspect the cam chain adjusters under each head cover. If the guide failed or broke then the chain could be metal to metal. Don’t wait on fixing it. Change the oil and filter. I would change it twice — once wit cheap oil and run it for 5 minutes, drain and then change it again (oil and filter) with the proper oil.

JAA 4.2

My 2000 A6 4.2 had a rattle from the tensioners when you revved it quickly. That vintage engine always did it. Mine was around 1000rpm. It made that noise for 100,000 miles. Yours doesn't sound like that. Ideally, pull the driver side valve cover and inspect the tensioner pad.

If you do need to change the tensioners it's considerable work. You have to pull the timing belt and driver side cams. Passenger side is easier. If you've never had an engine apart I wouldn't suggest it. The tensioners are roughly $500/side.

davek4300

My independent Audi shop is indicating it seems to be resonating from under the intake manifold. In fact upon inspection the intake seems to be missing some parts and the flaps are locked. Which is crazy because it has tons of torque and idles perfect., no hesitation sluggishness. Just that damn internal noise...almost like a metallic clicking. I'm getting a quote on a used /tested manifold.

btw..the chain and tensioners are good.

omlilleby

Hi.

Did you get any solution on the problem?
Have the same issue on my s8 d2

spitanddirt

I have had a problem with my power steering pump causing metallic hammering sounds just off idle. It can sound like timing chain rattle, but it's actually fluid cavitation and very specific rpms. Just something else to look at.