badavisjr

After warm- up, under boost, there is a pulsating clicking sound under the hood of my 1.8T Replaced the diverter valve with an upgraded model, but clicking is still there. Is coming from turbo system because when i push the clutch in and rev the engine, the clicking isn't there. After the turbo has boosted 5 times or so, the clicking goes away. Anybody have any ideas?

markbradford

Sounds like the knock sensor is cutting in after you try to give it floor 5 times in a row. This is BAD BTW - stop doing it. Do you have a chip? What kind of gas do you put in the car?

Need more info.

badavisjr

I have the MTM stage 1 chip, run premium all the time (from texaco, amoco, etc) I don't actually floor it, but as soon as the boost comes on (2000 rpm and up)under normal acceleration it rattles, then after a few minutes of driving, it goes away.
funny, though the boost is strong, even with the clicking. sounds more like a stick running quickly over a picket fence

dpd

you didn't say what year turbo and i think you re-placed the the diverter valve[for secondary air[2000/2001].your noise could be the turbo by-pass valve.if the car is 2000 i've seen the flywheel/clutch assembly rub the rear main seal adapter.the fix was to pull the trans and swap the aluminum spacer with steel.if the car is older than 2000,then when it's cold,pop the air boot off the turbo charger and check the axial play of the turbo,if the by-pass valve is good.[older cars didn't use secondary air or the engine/transmission spacer plate,so that wold eliminate them causing your problem].another sound bad turbo-by-pass valves make is during shifts or decels they make hooting sounds almost like a owl.

markbradford

If you do I'll bet it's the lifters. I've had all 20 replaced in my car and the noise (I call it a ticking noise) still hasn't gone away. They're going to put a new head on my car.

EdP

That sounds like pinging.

dpd

i've yet to see any audi cackle yet,even ones that ran completely out of coolant after the waterpump gernaded.they usually self destruct before they will ever detonate

markbradford

bad programming, or or it's too hot.