Loud turbo whistle from 2500+ rpm

[Matt D40]

Hey team , I've got a loud whistle coming on at 2500 rpm under load. I'm assuming boost leak and there is a bunch sooty junk that looks like it's coming from top of intercooler pipe at throttle body. Took it off and pressurised with soapy water and couldn't find a leak. Any one know where else this might be from?

 

[Matt D40]

Hey team , I've got a loud whistle coming on at 2500 rpm under load. I'm assuming boost leak and there is a bunch sooty junk that looks like it's coming from top of intercooler pipe at throttle body. Took it off and pressurised with soapy water and couldn't find a leak. Any one know where else this might be from?

To add to that, the seems to be no loss of power or extra smoke from exhaust ...

 

[Old.Tony]

It's tough finding these leaks like that, because the ECU won't command the turbo to spool up hard when the car's not moving, so you won't get full boost pressure while you're standing there spritzing the hose with soapy water.

Here's what I'd try:

1) Undo the join where the sooty junk is coming out.
2) Thoroughly clean this area, including the inside of the hose (petrol is great for this, just make sure you let it dry).
3) Reassemble and test.

 

[Matt D40]

It's tough finding these leaks like that, because the ECU won't command the turbo to spool up hard when the car's not moving, so you won't get full boost pressure while you're standing there spritzing the hose with soapy water.

Here's what I'd try:

1) Undo the join where the sooty junk is coming out.
2) Thoroughly clean this area, including the inside of the hose (petrol is great for this, just make sure you let it dry).
3) Reassemble and test.

Hey mate, gave that a go. Still happening. Tried putting a new O ring in on the hot side pipe too where I found a bit of soot coming out and still no luck

 

[Old.Tony]

Hey mate, gave that a go. Still happening. Tried putting a new O ring in on the hot side pipe too where I found a bit of soot coming out and still no luck

Ok, with those joins all re-done they shouldn't be leaking now anyway, so it's time to look elsewhere.

Question: does the whistle come on immediately, or is there a slight lag between revs rising and whistle coming on? If there's a delay, it's definitely turbo. If it's happening precisely at the same time as the revs increase, it might be the join between the exhaust manifold and the turbo. My own car did this (although mine sounded like a poorly played clarinet). the gasket thinned out and started acting like a reed instrument. Signs were there - black sooty powder around the join, a sure sign of a leak. Also check the EGR tube and consider blocking the EGR (on the intake side is easier) at least for testing.

 

[Matt D40]

Ok, with those joins all re-done they shouldn't be leaking now anyway, so it's time to look elsewhere.

Question: does the whistle come on immediately, or is there a slight lag between revs rising and whistle coming on? If there's a delay, it's definitely turbo. If it's happening precisely at the same time as the revs increase, it might be the join between the exhaust manifold and the turbo. My own car did this (although mine sounded like a poorly played clarinet). the gasket thinned out and started acting like a reed instrument. Signs were there - black sooty powder around the join, a sure sign of a leak. Also check the EGR tube and consider blocking the EGR (on the intake side is easier) at least for testing.

Thanks again for the tips mate, found the problem see photo...
Luckily I'm a boily so unbolted it and welded her up good as new

 

[Old.Tony]

Thanks again for the tips mate, found the problem see photo...
Luckily I'm a boily so unbolted it and welded her up good as new

Wow, imagine have a crack right on your flange!

Good find!

 

[Rhino1174]

I just repaired my daughters Hilux done exactly same thing but it wasn’t whistling it was absolutely screaming it’s head off you couldn’t stand to drive it

 

[Tms40]

Couldn’t help myself

 

[pistol-W]

Hey team , I've got a loud whistle coming on at 2500 rpm under load. I'm assuming boost leak and there is a bunch sooty junk that looks like it's coming from top of intercooler pipe at throttle body. Took it off and pressurised with soapy water and couldn't find a leak. Any one know where else this might be from?

I have the same,it was there before I overhauled the full top end inc chains, manifolds and turbo off... New gaskets ect.. Finished the rebuild and whistle still the same ... NO lose of power ect so not to bothered ?