1KZ Whistle

[fweddy]

My '94 Surf has been steadily developing a whistle. It was quiet and only showed up from about 2500rpm, you could play with it cutting in and out with the revs. Now it is there at lower revs but louder the higher the revs. Quite noticeable from inside and outside the vehicle.

When the engine is shut down there is a notable whistle/squeal that starts when the engine stops and drops in tone (like pressure releasing.)

I'm linking it with the turbo, is it likely to be a gasket or some such thing? Any other thoughts?

[zukmeista]

You're probably on the right track with the turbo, unbolt the intake pipe on the front and see if there is much play in the shaft. If there is enough play for the compressor wheel to touch the housing it needs new bearings.

[lexlux]

A exhaust leak will do it to , maybe a broken flexi .

[zukmeista]

A exhaust leak will do it to , maybe a broken flexi .

Considering the noise continues after the engine is turned off and slowly winds down the turbo would be the likely culprit.

[crazyclark31]

Defiantly the turbo going by that description.
I'd be getting it checked out quick smart. A new whistle sound can mean that the impeller has been knocked out of balance or the bearings are on their way out. Either way it'll need attention.

[Macca]

I had a similar noise on a turbo-ed 5L hilux. After tooing and froing with two mechanics turned out to be a stud on exhaust inlet to turbo being loose allowing copper gasket to whistle.

[tallsam66]

Fuel return valve can cause a whistling sound too. Part # 09602-00270 ( not 100% sure of part number)

[Heath]

Fuel return valve can cause a whistling sound too. Part # 09602-00270 ( not 100% sure of part number)

Part number: Denso 096020-0270 Screw Assembly
Fuel return valve.

[fweddy]

An update here for those interested. (I always hate it when you have the same problem and no one ever completes the thread of what the solution was.)

I didn't end up getting the time to remedy this myself and the vehicle needed to go in to get other things done so I got them to look at it. It proved to be a plate on the inlet manifold area that needed tightening down. Easy fix and a heap cheaper than my fears of the turbo needing work or replacement.