Noisy exhaust system at idle

[Potshot]

Got a very noisy exhaust system at idle - closest sound is screech of slipping fan belts - but it is not. As soon as you increases revs it disappears only to reappear on idle. If you move/push end of exhaust tailpipe it also stops!!! Driving me mad and very anti-social - ideas please???

 

[grantw]

My guess would be a smallish hole that is managing to "whistle" when only at idle.

Could also be the exhaust rubbing against the body or chassis somewhere ... thinking about it ... this is probably the probably cause.

 

[froggy Steve]

Ours was rattly a couple of weeks ago - the tail pipe had broken off the middle silencer! New mid and rear section ordered from ebay 130 eenglish pounds, delivered to France in 5 days!
Will (hopefully) get it fitted by my local garage guy on Thursday, who will do a service with the filter set ordered from Milners at the same time

Steve

 

[tsviatko]

Have somebody jam a rag at the end of the exhaust and hold it firm till the engine starts stalling while you're under the truck. Any leaks become way more obvious that way. Repeat that till you find the leak.

 

[clivehorridge]

Could it be the turbo? No expert at all in these matters, but I could imagine a faulty turbo could make a high pitched screech at tick-over revs and right itself when it spins faster on pick up and running speed.

Just a thought.

 

[Chas]

Could it be the turbo? No expert at all in these matters, but I could imagine a faulty turbo could make a high pitched screech at tick-over revs and right itself when it spins faster on pick up and running speed.

Just a thought.

Ooh! you jogged my memory there Clive, I had a Nissan 200SX that did just that, but in my case it required a new turbo. Ouch! I can't remember what it cost me but it wasn't cheap.

 

[clivehorridge]

I can imagine! I'm turbo-less, no worries there!

 

[Potshot]

Thanks for the replies:

@CliveHorridge - if it was the turbo why would the noise go when you moved the tailpipe without increasing revs?

@FroggySteve -the exhaust system is not rattly, it is only 2+ years old and appears to be solid and well attached. The noise is more of a screech rather than a rattle.

@GrantW - I think the system is in good nick so the whistle doesn't seem likely and can't locate a source. I am going along with your theory of contact with something.

Thanks all

 

[Yorkshire Devil]

Have your manifold bolts shuck loose? Have you snapped any manifold or turbo studs?