Thread: 300Tdi Turbo Squeal

The reason you can't get the whistle with no load is that the engine won't develop the required boost.

The manifold gaskets have a habit of cracking, although all that you usually see is that the block is wet with oil.
Pull the manifold off and check, but I'd still put money on a hose, or the boost compensator line from the turbo back to the fuel pump, or perhaps even the diaphragm there, although I don't recall ever hearing of one perforating.

I had similar symptoms when I had hole in the waste gate actuator caused by shorting it across the starter terminals when installing the manifold. The repairer was too lazy to disconnect the batteries.

squeal???, maybe a better descriptor,
is it squealing . maybe the turbo bearings are shot or the oil feed line is blocked,
just a guess,
but you say no power at 2,200 , what speed are you doing for those rev's, that would give a better idea of what the problem is.
When the engine is not under load its hard to fault find weird noises.
i had a small split in the 90 drg hose from the turbo to intercooler, it was rubbed through by the bypass clamp above it. I think the boost side pressurises the lines and with a hole it won;t give you boost pressure.
( after all its a long way from the turbo to the inlet valves)
you could just take off the lines on the turbo and intercooler side and inspect them for holes, check the intercooler, maybe there is a hole in it.

this may help your problem


john

Hi John,
The noise happens when going through the gears and even at 60kph in top if you put your foot down. I inspected the hoses over the weekend and could not find any holes. When I drove it to work this morning the noise was alot less when the engine was still cool but when it heated up the noise was louder. It may be the manifold gasket as Rick has pointed out but I have not seen any oily residue around it. My first thought that it was the intercooler but there is a bit of work to get it out and pressure test it. The noise is turbo related as the noise appears and disappears with throttle movement and it sounds like a high pitched whistle like some trucks have. I hope this helps to describe it.

Mine had a high pitched whistle under load which wouldn't do it just free revving and the result was a hairline crack in one of the hoses. The small 12mm hose near the turbo from memory.

The turbo was removed as i had a finer filter disintegrate through it and one of the vanes was bent however the turbo people in Toowoomba advised the noise was from the hole in the hose not the bent vane.

Phillip;

Rick is on the money, been there before , remove the Air Hose to Turbo from Air Filter box , remove your intercooler Hose and shine a torch on the hose from wastegate actuator , guaranteed to be that on inspection , your Boost compensator line ( Boost Signal Hose ) it has some dicky clips and they don't do a proper job of keeping the line pressurised. I have replaced mine with proper circlips.

curious
how did you go, was it a hole/loose clamp in the main air lines or the boost line to injector pump.


john

Hi i have had very similar symptoms to this. I have changed the two pipes from turbo to intercooler in the hopes it was one of these. Does anyone else have any other possible suggestions or know how Treads fixed thiers. Any help would be appreciated
Cheers Josh