Hi Guys 👋
My first post in here, so please be nice!
I’ve had a search through here and the diesel engine threads, but can’t find anything like what I’m looking for.
Long story short, my 2015 XC60 with 2.4 D4 engine is making a weird noise while under load/heavy acceleration.. but only in 4th gear upwards, and only between about 1300 and 2000 rpm.
The noise starts out as you hear the turbo start to spool at about 1300rpm or so (you can hear the high pitched spin of the turbo starting) and then a whiney/squeely/almost-rattly-but-not noise overpowers this up until about 2000 rpm when the noise dies away to nothing and the sound of the V5 and turbo dominate (much to my amusement..).. also, as the turbo obviously doesn’t kick in properly until about the time this noise stops, the car does vibrate the smallest amount (being a diesel, I attribute the vibration to just that, as tractor engines are known to chug aren’t they!) so I don’t know if it’s just a really rapid rattle..?
Equally, if I accelerate steadily the noise isn’t there.. you can still hear the turbo wanting to spool up, but no other high pitched noises.
It’s almost a similar noise to what you get in an older car on start up, when a belt is slipping and you get that squeal as the car is rev’d for a little while.
What is throwing me off is that I haven’t heard this noise in 3rd gear or below.. only 4th and above (maybe because the revs jump up to 2000 rpm so much quicker??).
Could be a belt that’s lost it’s proper tension? But would it stop making noise above a certain rpm of that was the case, and would it only be in higher gears?
I’d offer turbo bearings as a possibility, but again, it’s only in higher gears (longer spool time because of bigger gears higher up gear box so issue/sound becomes prevalent maybe?).. and as said, if taking it steady you can still hear the turbo wanting to spool up, and if you boot it above 2000 rpm there’s no nasty noise, just boost and engine noise!
Not had chance to check all fluid levels yet incase something is running low so can’t rule that out.. but does anyone have similar past experience? If so, what was involved!
Car doesn’t feel lumpy, plenty of power, no warning lights, no codes etc.. just a really annoying noise!
Thanks in advance guys.. and sorry for the really long bedtime story I’ve just written
