Strange noise only lasts for 5 to 10 seconds

[Domalom]

So recently i have noticed a strange noise coming from the engine, it normally happens when i start the motor, more regular when i start it after it has already been running but sometimes will happen on first start, sometimes it will only last for a couple of seconds and sometimes it lasts for much longer.

The noise is strange to me, i have never heard it but it starts off quiet and then it gets louder and just before the noise goes away it gets really loud and then is disappears.

I have attached a video of the noise here, it is the whistling sound, listen carefully.

If you want anymore info please ask, thanks.

 

[Old.Tony]

It's just the brief "whoosh" in the middle?

There could be a number of causes. I'd first suspect a gasket in the exhaust (probably between the exhaust manifold and the turbocharger, but just look for sooty deposits around the joins).

It could also be a boost leak. You can spot this from the black oily streaks coming out in the path between the turbocharger and the intake manifold (through the intercooler).

There's a chance that it's a fault in the EGR (possibly a hole/crack in the pipe) - this is the gold pipe that runs around the front of the motor, it has a pair of rubber hoses connected at the top that carry engine coolant so be careful with these. Check the gasket at the join between the EGR pipe and the EGR valve that sits on the end of the intake manifold, but also inspect the pipe near where it joins the exhaust manifold where it's failed on a couple of occasions in the past.

Otherwise it could be like mine (mine makes an odd screeching sound sometimes, more often when cold) when the belt passing over my power steering pump decides to slip. Dri-lube fixes my sound issue. If you've lubed all the belts and still get the sound, it could be coming from the alternator - on my original alternator, the key in the pulley shaft broke/wore through (how, I don't know) and this allowed the pulley to basically float on the end, causing me charging issues as well. I didn't want to off-balance the shaft by welding it up, so I just replaced the alternator.

Another thing you should check is the back of the radiator, look for signs that the radiator fan has scraped against the radiator itself. This can happen if the fan develops cracks particularly near the root of the blade.

 

[Domalom]

It's just the brief "whoosh" in the middle?

There could be a number of causes. I'd first suspect a gasket in the exhaust (probably between the exhaust manifold and the turbocharger, but just look for sooty deposits around the joins).

It could also be a boost leak. You can spot this from the black oily streaks coming out in the path between the turbocharger and the intake manifold (through the intercooler).

There's a chance that it's a fault in the EGR (possibly a hole/crack in the pipe) - this is the gold pipe that runs around the front of the motor, it has a pair of rubber hoses connected at the top that carry engine coolant so be careful with these. Check the gasket at the join between the EGR pipe and the EGR valve that sits on the end of the intake manifold, but also inspect the pipe near where it joins the exhaust manifold where it's failed on a couple of occasions in the past.

Otherwise it could be like mine (mine makes an odd screeching sound sometimes, more often when cold) when the belt passing over my power steering pump decides to slip. Dri-lube fixes my sound issue. If you've lubed all the belts and still get the sound, it could be coming from the alternator - on my original alternator, the key in the pulley shaft broke/wore through (how, I don't know) and this allowed the pulley to basically float on the end, causing me charging issues as well. I didn't want to off-balance the shaft by welding it up, so I just replaced the alternator.

Another thing you should check is the back of the radiator, look for signs that the radiator fan has scraped against the radiator itself. This can happen if the fan develops cracks particularly near the root of the blade.

Yes, it's that "whoosh" but it happens more often after i have been driving for a while and then turn it back on after being off for a few minutes. Most of the time it will happen at the fuel station when i turn it back on.

I will have a look at all these things and let you know if i find anything like you have said.

Thanks for the help!