seized turbo

[snbeffort]

I think the turbo is seized in my L300 . There is a whistling sound at higher speeds and it seems to be sluggish and changing gears from 4th to 5th too frequently ( automatic ). Also fuel consumption has gone up. What am I looking at for a turbo replacement? rebuild?

[Growlerbearnz]

If it is seized, you'll likely need a replacement bearing housing, at which point it's cheaper to buy a whole new turbo.

That said, what you describe sounds more like a split or detached boost hose. The one that goes from the turbo to the injection pump would be my first suspicion, but any boost leak can cause the same symptoms. You're looking for loose clamps and evidence of oil/air being ejected from any rubber parts of the intake system. The short hose between the turbo outlet and intake manifold is another likely suspect.

If it's not any of the hoses, remove the boost compensator cover (the metal thing the boost hose connects to) from the injection pump and check the diaphragm inside for splits. **note the diaphragm's orientation before removing it. Putting it back in a different position (rotated) will change your injection pump's tuning**
(Here's a diaphragm marked so it can be replaced the same way:

repere.jpg (14.22 KiB) Viewed 2826 times

)

While you're in the engine bay checking the hoses, it's easy to check the turbo too- remove the ribbed rubber inlet pipe that goes to the centre of the turbo (you'll have to do that anyway to check for boost leaks), and spin the turbo impeller by hand. It should turn easily, have no more than 1mm of side-to-side play, and virtually no axial (in/out) play.

To get at all these bits you'll first need to remove the drivers side engine cover.

[snbeffort]

Great thanks,. I'll give it a try

[TieMyShoe]

The other thing that can cause a whistle is the 3bolt gasket between the manifold and the turbo, or the manifold gasket itself. Have a look for carbon tracing around the manifold gaskets, when they blow out the gasket acts like the reed in a clarinet making a lovely "WEEEEEEEEEEE" sound on heavy throttle input. This in turns drops turbo drive pressure to the turbo, and in turn drops boost level and power, making for sluggish driving.