2008 D5 Oil Filler Popping - Even When Vacuum Line Clamped
 

As per title, When I'm getting the usual popping noise, and some smoke from the oil filler, but the sound doesnt change at all when I clamp any of the vacuum lines from the vacuum pump.

Could this be the PCV? there is a fair bit of oily residue around the pipes for this. It is also chuffing out of the swirl flap lever area under load.

No sound round the intake of air box, so hoping its not the dodgy valve lifter issue.

Thoughts and first hand experiences of what it could be?

Thanks

The euro 4 engine uses a completely different vacuum system to earlier models. Popping and white smoke from the filler cap is normal. My car has it, my dad's car has it and it makes absolutely no difference to the running of the car. The only time I hear the popping noise is if I remove the oil cap.

I learned to live with it.

But would the smoke coming from the swirl flap lever area indicate too much pressure?

Popping goes away if you repair leaks in the vacuum tract (engine mounts /egr bypassvalve with manual transmissions)
The popping noise is discharged air which is sucked in trough leaks , with perfect vacuum there is no air to pop in the valvecover ;-)

https://www.youtube.com/watch?v=GsiMgQuITSI

No, there shouldn't be smoke coming from that area. As for the popping noise, I learned to live with it. I can only hear it when I take the oil cap off with the engine running. It doesn't affect the running of the car.

It’s not too clear from that video what he’s doing. Presume removing the pipe from the vacuum pump to initiate the popping?

If I clamp the hose, it makes no difference. If I take the brake booster pipe off, the popping almost disappears. Brakes appear to be fine.

He is me ;-), removed the hose of the enginemounts to induce air popping

Then you have a tiny leak in the breakbooster,(separate bigger hose)so the vacuum pump can generate enough vacuum to let it function but the amount of removed air causes the popping sound

Right, thanks.

I’d better check the pipe work between the booster and the vacuum pump.

A little update. I haven't had a chance to investigate the brake booster hose yet, but have noticed that I can hear the popping through the intake area when the engine is hot.

Does this point more towards Lifters? What years are more likely to suffer this?

post a clip