Afternoon All,

Have just noticed (another...) new noise that has appeared on our '17 2.0 diesel PS Galaxy. Only appears on relatively strong acceleration as far as I can tell, e.g. getting back up to speed after a 30 zone when going uphill or similar. Starts audibly when you push on the pedal and then dies away when you ease off, my wife had described it as a 'gurgling' sound when she first noticed albeit to me it sounded slightly more metallic, a little like a running chain noise or similar. Feels like it's coming from pretty much dead ahead of the driver's seat, perhaps biased slightly to the right. Any thoughts? Anything in that area that might should (might?!) make an atypical noise that I need to investigate further? Can see me trying to find hills to accelerate up in order to try and record a snippet....

 

Any guesses welcome : ) 

 

Sandy

You could remove the auxiliary belt to rule out the alternator, AC compressor and belt tensioner.

Sadly the cambelt (and mini cam chain) are all in that area and not easily checked.

The water pump may be cavitating but that should be high RPM rather than high load.

The turbo vanes close under high load, which changes the sound of the turbo boost slightly.

The injection timing is advanced slightly when more load is requested which can cause diesel knock.

Ambiguous noise threads are always difficult lol.

Many thanks Tom, that's really handy. As you say, lots of stuff in that area annoyingly! Certainly high load rather than rpm seems to be the trigger but I'll need to try and make things down. I did notice that commander was quite low as there seems to be done residual small weep loss following a recent thermostat housing replacement so I might try tipping that neck up to full to rule out any coolant level issue making water pump noisy.

 

The timing belt and aux were both changed within the last few months so hoping there's no issue there but I don't know if there's any easy way of checking health of the little timing chain under the oil cap...

I might have to Google 'diesel knock' for door samples to roller that out. Not something I'm familiar with unfortunately! 

It does seem to have coincided roughly with a period where it feels like I'm getting a lot more vibration through into the cabin at idle and load along with a bit more visible wobble of the engine block when outright with bonnet up. Always tricky to try and strive if symptoms linked or just incidentally occurring at the same time!

Many thanks for comments, will see if I can turn up anything to narrow it down a bit.....

 

Cheers,

 

Sandy