Hi all,

Of late I have had a strange rattly sound, almost metal in tone when I hit my boost hard.

On tests....

It appears on 1, 2, 3, 4

I can only hear it in 3, 4 if i bean it

If I drive smoothly then its doesn't appear

It happens as the boost cuts off at 3000 odd revs

doesn't matter how fast I am going, if I put the boot down it will appear only at that rev range.

No dash lights, no loss of power, no funny smells.

Sounds like it is behind the dash/where the DV is.

The DV is a compbrake.

Not sure what else there is to know.

Have you had a look at the actuator rod etc.? Although if that's got something wrong with it you'd definately notice a difference in how it drives.

You could always put the standard DV back on to see if its the Compbrake DV thats making the noise. Is there any sideways play in the piston in the Compbrake DV?

Your boost cuts off at 3000 rpm?

Your boost cuts off at 3000 rpm?

Think he means thats when the wastegate opens so the boost doesn't go any higher?

Oh got ya lol

As said try changing your dv for the standard one if you still have it.

I was having issues with my compbrake dv as it wasnt sealing probally fitted my standard one back on and havent had any problems yet

Boost finish around 3,5 some where up there but the noise comes in as the boost is ending. It's defiantly still got its power! Tried that one tonight. How do I test for sideways play in the piston?

Unscrew the body and check it at a guess

When you say the noise comes in as the boost is tailing off makes me think its something to do with the wastegate.

You can check play in the DV piston by poking it with your finger through the side port of the DV, it shouldn't move at all in a sideways direction (only up and down on the spring)

If it's moving sideways then thats a good candidate for the metallic rattling.