300tdi Whistle under load.

[TylerN]

I’m new to Diesel engines, and am looking for a bit of advice.
I picked up a 97 Disco that has had a 300tdi and 5spd swapped into it. Love it. The previous owner swapped out a bunch of the piping to terra firma silicone replacements, but told me he hadn’t done the “ little one in the back” it has now developed a whistle under load or acceleration, which I can’t replicate stationary. He seems to think it’s the aforementioned “little one”. Does anyone have an idea which one he’s talking about and where I need to look for it?? :?:

[red90]

Normally a whistling noise under load is a boost leak between the turbo and the engine. Check all of the connection and hoses carefully.

[Tony4921]

He could mean the boost enrichment line. It goes from the fuel injection pump, usually around the back of the valve cover to a boost pipe near the turbo. If this one is split or come off, the engine is fairly gutless however.

[cbalme]

I know the 90 degree hose that exits from the turbo is small and black. I have had that one collapse internally which caused a breakdown on the Malahat.

[HeadDamage]

I took me quite a while to track this problem down in my 200tdi. In the end I had to rig up a way of pressurizing the intake system with an air compressor to find a few very small leaks with hose connections etc... but the main issue turned out to be an exhaust manifold leak that only showed up under load, it was in a really difficult spot to see as well.

[TylerN]

I think I found it, a small loose connection under one of the main hoses, snugged it up and seems to have stopped.