Funny noises.
Well, just the one… Truck has recently started making a kind of chirping noise, metallic, similar to a bearing failure, but not quite as harsh.
Thing is this only ever occurs when the engine is under heavy load, and on a Hill, and only around 14-1500 rpm; and only with the accelerator depressed. If I lift my foot and hold the engine load steady, the noise always goes away.
Definitely not a belt slipping noise…
If it’s just under them circumstances it doesn’t seem like an issue.
I’d be looking at the pulleys or the prop shaft possibly.
Crystal ball guess. An Intercooler pipe with a loose clip, a hole or a faulty intercooler rad itself, all make weird noises which can be hard to describe in exactly those circumstances. If you have a boost pressure gauge it just might show up as a lower reading than normal. But I’m no wizard so probably wrong.
As above, check the boost hoses first…
I’m with Cav and Andrew. High pressure air on the turbo somewhere. Whistling through a gap and a bit of rubber off a split hose flapping about.
Sent from my GT-S7275R using Tapatalk
Had this on a Scania years ago, there was a short piece of exhaust that sits between the turbo and exhaust brake, if this becomes loose this will give the metallic sound when you boot it. Also when you are on the exhauster.
An intercooler hose will tend to give more of a whistle it will also affect power as you are effectively non turbo.
If the power is still up I would suspect something further ‘down stream’…
Your the driver, wait for it to stop, then ring in. You could just defect it.
biggriffin:
Your the driver, wait for it to stop, then ring in. You could just defect it.
I’m also the Boss, unfortunately…! 
Sounds to me as if it’s offside, around the area the AdBlue injects into the exhaust. But surely there are no moving parts there, just an injector…?
The intercooler hoses run in that direction either side of the engine mind…
el_presidente:
biggriffin:
Your the driver, wait for it to stop, then ring in. You could just defect it.I’m also the Boss, unfortunately…!
Sounds to me as if it’s offside, around the area the AdBlue injects into the exhaust. But surely there are no moving parts there, just an injector…?
The intercooler hoses run in that direction either side of the engine mind…
Put some Fairy Liquid over the hose joints, drive down the road, if you see a trail of bubbles you`re solved the mystery!
Adapt to suit circumstances.