whats that whine/whistle at 2500 rpm??

[Mike k]

Hi all just returned from a great day out in the mersey estuary, lovely weather and altogether pleasant cruise with 2 friends who were brilliant crew, although in admit i thought Andy had gone a bit far when he went on the bow at 10 knots to clean the windows of sea spray!!

Anyway as forumites will know, im pretty new to this and constantly listen for any new noises- today at 2500 revs a whine/ whistling type noise was heard coming from the engine somewhere-nothing dramatic but it did change pitch as we moved to 3000 rpm and down again to 2500 and couldnt hear it below that. The engine is a 2.5 turbo deisel , only 280 hours- any thoughts greatly welcome????

 

[Seahope]

Hi all just returned from a great day out in the mersey estuary, lovely weather and altogether pleasant cruise with 2 friends who were brilliant crew, although in admit i thought Andy had gone a bit far when he went on the bow at 10 knots to clean the windows of sea spray!!

Anyway as forumites will know, im pretty new to this and constantly listen for any new noises- today at 2500 revs a whine/ whistling type noise was heard coming from the engine somewhere-nothing dramatic but it did change pitch as we moved to 3000 rpm and down again to 2500 and couldnt hear it below that. The engine is a 2.5 turbo deisel , only 280 hours- any thoughts greatly welcome????

Perhaps you are hearing your turbo working?

 

[sarabande]

have you checked for cavitation, in case the noise transfers through the hull to the engine room ?

 

[TheBishop]

It's the turbo

 

[Mike k]

not heard it really before so is it normal?

 

[Mike k]

Hi Sarabande/Bishop/Seahope - thanks very much for your posts-I dont think its cavitation as i have been told that you get a a very bubbly wake behind the prop and i get a pretty clean rooster tail wake when motoring. I wonder then if it is the turbo then is this noise pretty normal even though i havent heard it before?

I have to say the boat was ashore for 18months until March this year when i bought her and even though i have motored her about 10 times ( 5 at speed) is it poss the turbo has kicked back in proper now after its long period of inaction??

Ps saraband I have ordered some spring lines as per our thread as few days ago - thanks again.

 

[duncan]

more likely you have just noticed it!

it's one of those sounds that generally blends in, esp on road vehicles, with background noises that also change with engine speed changes.

if you need convincing, open engine bay, put in neutral and increase the engine revs (obviously with the boat in the water!) and you will be able to directly relate it to the turbo kicking in and 'whining'

 

[Mike k]

thanks Duncan so is it normal then?

 

[duncan]

thanks Duncan so is it normal then?

well it is on my boat and landcruiser (both 4 cyl turbo diesels)