Member Since: 18 Sep 2016
Location: CARDIFF
Posts: 38
Inrush of air on acceleration - D4 2015
Can anyone help - my D4 has started to make some loud air inrush noises under heavy acceleration - no sure if this is also related but the turbo also seem to dump air as well very loudly through its dump valve after the inrush sound when you lift off the accelerator? Im pretty sure its always vented like this around the turbo dump but never got this loud inrush sound before on this one so something has changed
The noise I am refering to sounds exactly like the noise you get from a split in the large intercooler pipe on a D3 (I had this fault previously on a D3) where it sucks air in through the split.
I went to see if it was the same issue on a similar layout but the 3.0 D4 is clearly a different hose configuration and not quite sure where to start to look for the possible split on this on or even if therer is a split and ive just put 2+2 together and come up with 5!
Any advice would be greatly appreciated,
Thanks Graham
30th Dec 2022 11:07 am
Flatlander
Member Since: 20 Jul 2015
Location: Here
Posts: 575
It does sound like a charge air hose has split - look for oil deposits.
There is no 'dump valve'.
30th Dec 2022 11:10 am
Welsh Wizard
Member Since: 18 Sep 2016
Location: CARDIFF
Posts: 38
Thanks - any pointers as to which hoses Im looking at? Is it this one and Im assuming there is another buried deep on the other side lower down somewhere?
30th Dec 2022 11:20 am
Flatlander
Member Since: 20 Jul 2015
Location: Here
Posts: 575
There's the available charge air hoses - don't forget to check the intercooler for damage, a smoke test is the easiest way to find a charge air leak.
I'd also suggest taking the engine cover off and checking the inlet manifolds
30th Dec 2022 11:27 am
Welsh Wizard
Member Since: 18 Sep 2016
Location: CARDIFF
Posts: 38
Awesome Flatlander - picture speaks a 1000 words
the main top hose looks ok (just started there as nice and accessible - wishfull thinking on my behalf that it was going to be that easy, as it is a Landy after all and nowt is ever simple) so diving in to find the others - is it skid pans off for the lower hoses?
30th Dec 2022 11:42 am
Welsh Wizard
Member Since: 18 Sep 2016
Location: CARDIFF
Posts: 38
Managed to find one problems - (the air inrush noise) as one of the hard plastic air charge hoses had come undone - i dont think it has worked loose as there was no way the pipewould come off over a lip on the receiving pipe (which was also hard plastic) - i Backed the jublilee clip off and still wouldnt go back on untill It was really loose and still an absolute pain to get it back on - the engine was changed 30k ago and me thinks they didnt push that back on properly over the lip, just been tightened up on the very edge and its worked its way off again - thanks again Flatlander for the pic as was able to track it down quickly with that....
The other issue though is still there - when hard accelerating, it may be when the turbo is at full boost, it vents and you hear a large balst of air -best way I can describe it is a bit like air brakes venting on an aritc when it puts the handbrake on and disipates the air.
If there is no dump valve as such, is there some kind of pressure valve which may be venting under pressure? I think its its got worse over several months? Im sure it used to vent when you lifted but now its started under acceleration and comes in in line with when you'd expect the turbo to kick in...
Ideas on a postcard...
30th Dec 2022 1:59 pm
Flatlander
Member Since: 20 Jul 2015
Location: Here
Posts: 575
Same answer really - check for oil deposits around ther charge air hoses, also check the part labelled 6K770 on the screenshot above, the 'O' ring on the throttle body can get trapped in the spring clip and cause charge air leaks at high pressure, other than that, it's back to checking from the turbos upwards i'm afraid. There are so many potential leakage points - particularly if the engine has been out or 'heavily' worked on that I wouldn't like to suggest too many wild goose chases - but from your description, it's on the charge air side rather than the air intake side. The R/H turbo is the secondary so it's most likely that set of pipes & ducts that is leaking, if it were the primary, you'd notice it all the time.
Known issue for other marques too ... souped-up VW Golf owners apparently use self-tappers to keep the joint from blowing open..
Dean
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2011 D4 XS - OBD port protection, RLD spare wheel protector, All LED interiors lights, Timed Climate enabled, iiD tool paired.
2011 D4 Landmark - Stolen from same dealer before I paid for it
2011 D4 GS - Stolen whilst at dealer ... All LED interiors lights, DRLs, Spare Wheel protector.
1996 300Tdi - Eaten by tin worms
30th Dec 2022 2:34 pm
Welsh Wizard
Member Since: 18 Sep 2016
Location: CARDIFF
Posts: 38
Thanks for the heads up Dean - planning to take another look tomorrow - weather permitting.
8th Jan 2023 12:23 am
Welsh Wizard
Member Since: 18 Sep 2016
Location: CARDIFF
Posts: 38
Flatlander wrote:
Same answer really - check for oil deposits around ther charge air hoses, also check the part labelled 6K770 on the screenshot above, the 'O' ring on the throttle body can get trapped in the spring clip and cause charge air leaks at high pressure, other than that, it's back to checking from the turbos upwards i'm afraid. There are so many potential leakage points - particularly if the engine has been out or 'heavily' worked on that I wouldn't like to suggest too many wild goose chases - but from your description, it's on the charge air side rather than the air intake side. The R/H turbo is the secondary so it's most likely that set of pipes & ducts that is leaking, if it were the primary, you'd notice it all the time.
After reading your post, Ive done a bit more investigation and homing in on the secondary turbo - I did a bit of googing to understand how the 2 turbos operate and stumbled across this
- you are defo on the money with the secondary as its drivers side noise and comes in around 2.5-2.8k revs, exactly when the secondary trips in - it has also helped to see what pipe went where from the turbo back (for me to focus onto, as you've suggested). Just thought I'd pop it in the thread for others - hopefully I'll be able to pin it down tomorrow - really appreciate the advice & direction
When you say its charge air side, I'm assuming that is the pipe in orange below? (apologies for my lack of tech knowlege) - I've also marked on the pic the joint that was loose/apart that I mentioned above incase others get something similar and one to check....
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... All LED interiors lights, DRLs, Spare Wheel protector.
