D5 popping sound

[Kev0607]

Hi all,

I was doing some fluid checks on my car before it went in for its MOT, but I had the car running because I was testing the lights too. Anyway, I decided to open the oil filler cap & heard what I can only describe as a popping sound & there was a bit of white smoke visible too. The noise itself seemed quite prominent, but I'm wondering is this noise normal on a D5 engine?

[ca2n]

Excellent explanation about the D5 popping sound in the video below from one of our knowledgeable members:

https://www.youtube.com/watch?v=QHLyubTrIQ8

[Kev0607]

Interesting... I wouldn't have suspected the engine mounts to be the issue!

Is it safe to drive the car with this popping sound, or do the engine mounts need to be replaced ASAP?

[Peter2400]

Originally Posted by ca2n

Excellent explanation about the D5 popping sound in the video below from one of our knowledgeable members:

https://www.youtube.com/watch?v=QHLyubTrIQ8

Does this apply to euro 4 D5 too (in vid it's euro 3 i think)? Because i know that in euro 4 turbo is controlled electronically not by vacuum.

[fennycruz]

Originally Posted by ca2n

Excellent explanation about the D5 popping sound in the video below from one of our knowledgeable members:

https://www.youtube.com/watch?v=QHLyubTrIQ8

I have bought 2008 xc90 d5 for my dad 3years ago with this noise. I knew then that it was something to do with vacuum but could not find what. Ever since it bothered me but now I know what it is and can fix it. Thanks

[Kev0607]

Originally Posted by Peter2400

Does this apply to euro 4 D5 too (in vid it's euro 3 i think)? Because i know that in euro 4 turbo is controlled electronically not by vacuum.

Good point. Does anyone know?

[psl]

I have the same on my euro 4 engine, its exactly the same

[Kev0607]

Originally Posted by psl

I have the same on my euro 4 engine, its exactly the same

What's exactly the same? I looked in my engine compartment today & its different to the Euro 3 linked into the YouTube video above. I couldn't see any vacuum lines, nor could I see the engine mounts?

All the posts I can find, even on other forums that mention a popping noise on idle relate to euro 3 engines. So does the popping sound relate to a vacuum leak on all D5's?

[cheshired5]

The popping noise is vacuum related on Euro 3 and 4 D5s with the only difference being that Euro 4 have fewer possible causes so leaking engine mounts, vacuum pump seal, brake booster seals, pipework/unions etc.
A cheap vacuum tester is normally all that's required to narrow things down and you can nearly always confirm a vacuum leak by seeing a fluctuating tester needle.
There are several vacuum related videos on my YouTube channel.

[Kev0607]

Hi cheshired5,

Do you have a link to the pressure tester & pipe that you used?

EDIT: I found it