whistle when accelerating

[littleun]

Just passed it's mot (couple advisories) I told mechanic it felt a bit sluggish and he suspected a vacuum leak as he heard a whistling when under load, to me it sounds more of a whoooooing than a whistle, is there anywhere specific I should look i.e a common fault on them, it's a 2.0 litre cdt, thanks for any help...

[LeRich]

Possibly a boost leak from a split intake pipe or intercooler elbow o-rings.

[COLVERT]

If it's a vacuum leak you'll feel it as soon as you try the brakes as you will think you have none.---

[bl52krz]

Could be the pipe from the inter cooler to the egr.If it has got a split in it, you will know if you plant your foot on the loud pedal because a load of black smoke will follow you up the road.

[Ducati750cc]

Originally Posted by COLVERT

If it's a vacuum leak you'll feel it as soon as you try the brakes as you will think you have none.---

Littleun said " I told mechanic it felt a bit sluggish and he suspected a vacuum leak as he heard a whistling when under load,"



An engine vacuum leak on the CD engine has no affect whatsoever on the brakes.


The vacuum for the servo does not come from the induction system i.e. an inlet manifold tapping but from an engine mounted vacuum pump !

[COLVERT]

Originally Posted by Ducati750cc

Littleun said " I told mechanic it felt a bit sluggish and he suspected a vacuum leak as he heard a whistling when under load,"



An engine vacuum leak on the CD engine has no affect whatsoever on the brakes.


The vacuum for the servo does not come from the induction system i.e. an inlet manifold tapping but from an engine mounted vacuum pump !

Quote:--The vacuum for the servo does not come from the induction system i.e. an inlet manifold tapping but from an engine mounted vacuum pump !

Everybody knows that and if there's a leak the brakes ARE affected. My post was a warning.

So please don't try to side track it.---

[Ducati750cc]

Originally Posted by COLVERT

Quote:--The vacuum for the servo does not come from the induction system i.e. an inlet manifold tapping but from an engine mounted vacuum pump !

Everybody knows that and if there's a leak the brakes ARE affected. My post was a warning.

So please don't try to side track it.---

I am not trying to sidetrack anything at all.


I was simply answering the statement by made by littleun "............."I told mechanic it felt a bit sluggish and he suspected a vacuum leak as he heard a whistling when under load,"so those two symptoms suggest that it is an engine vacuum leak and not remotely connected to or could affect the brakes, and no mention of servo problems.


I was differentiating between an engine vacuum leak, as suggested by his mechanic who had heard it when the engine was under load and the mention of the vehicle feeling sluggish and your suggestion...............If it's a vacuum leak you'll feel it as soon as you try the brakes as you will think you have none...............why mention the brakes at all when on this engine a vacuum problem would have no detrimental effect on the brakes whatsoever and could be misleading to someone who didn't know that the vacuum for the brakes is provided by the vacuum pump.



You say............ " Everybody knows that and if there's a leak the brakes ARE affected. My post was a warning."........... Many folk may know ,that a vacuum leak will affect the brakes, but likewise many folk may not know that the leak described in the post will not affect the brakes and many folk may not know about the vacuum pump.


It would have been better if you had qualified your quote as follows..........
If it's a vacuum leak you'll feel it as soon as you try the brakes as you will think you have none, but on this engine,this will only happen if the vacuum leak is on the vacuum pump to servo circuit but not, as in this instance, an engine vacuum leak................