whistle turbo toyota 2.0 D4D

A light whistle is good. This is your turbo spooling up. A loud whistle or grinding is not good., This is your turbo chewing up.

After parking the car, esp after being 'on the pipe' (turbo adding boost), idle the car for about 3 minutes. This lets the oil circulate and cool the turbo. Otherwise, the oil solidifies and THEN you hear the grinding!

More than likely it's perfectly normal - when the turbocharger spins up form the exhaust gases, it can hit 50,000 RPM or a bit more. The spinning of the turbine wheels makes a whistling noise.

If you want to be sure, or just to keep an eye on it, install a vacuum/boost combination gauge on the intake manifold vacuum line. At idle and low speed you'll see a vacuum like on regular cars, when you get on the gas it will pop over to boost.

Having a boost gauge isn't that useful day to day - except as an efficiency reminder to not keep your right foot planted on the floor all day. Good for fun, Bad for fuel mileage. ;-)

But you can instantly see if something is (or is going) wrong, because the gauge will go higher or lower than "normal".

Oh, and always sit and idle the engine for at least 30 seconds to a minute before stopping it, three minutes if you've been on the boost in the last five minutes. You need to give the turbine a chance to slow down to barely spinning at idle and cool off, so it lives longer without trouble.

When you stop the engine the oil pressure goes away, and the engine oil is also cooling and lubricating the turbo bearings. If the turbo is still glowing red hot and spinning 25,000 RPM when you stop the oil flow, it is very bad on the bearings.

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I'd say ONLY if you've been driving hard right before parking. Otherwise, modern water-cooled turbos will be fine.

In my case, I drive through a residential area on the way home. This is not an area where I can get-into the boost, and is as good as idling, IMO...

If you are using boost then yes, by all means you should let the care idle for 3-5 minutes before you shut down. If this is not convenient for you, buy a turbo timer.

Idling at the end of a journey is, IMO, not the best solution. All turbo'd cars, even modern water cooled ones, should be allowed to cool after a hard press (Even with the water/oil cooling and being placed right behind the rad my car running standard boost levels will get a cherry red exhaust housing), running high boost i get to see the shape of the *inside* of the manifold. Now TDs run lower pressures so its not quite as important but still a good idea to let the sucker cool. James' points to note on cooling yer turbo:

At-idle cooling: (Have a good blat up to the house/village and then idle in the drive) Hot exhaust gasses still flowing through the turbine and no air over the outer surface More pressure on the oil seals in the turbo. Lowest possible oil pressure feeding the bearings.

Coasting or over-fun cooling: (Blat to part way home, then use natural downward slops/traffic lights to *engine* brake as far as possible) Exhaust gasses on overun decelerating from above 1500rpm on petrols (lower on TDs) will induce fuel shutoff on all modern EFI cars. This means no fuel is fed or ignited until you drop below 1500rpm. This in turn means you are passing cool air through the entire engine inc turbo, cooling it rapidly. Air still passes through bonnet cooling from outside. Oil and water pressures still high maintaining proper lubrication.

To cool to non-glowing temps from my daily hard blast that gets a good glow on; Idle cooling (as with a turbo timer) - 5 minutes. "Overrun" cooling, 1.5 miles - cooled before i get to the drive, no glow. I've also noted that when ive really given it some stick its taken upward of 7 minutes idle cooling to get the turbine to stop glowing and return to normal temps.

SO all in all I'd say in-gear coasting as much as possible the final 2 miles to home is the best method for the turbo. If you want to sit in the drive with red hot oil passing over a nicely softened oil seal with a large vacuum on the other side for upward of 5 minutes - feel free :D

In answer to the original post - its likely normal unless its got a shrill vibrating to it, then its likely your turbo bearings are dead/dying. J

Just to clarify this, i meant by the relative vacuum outside the seals, not by the oil.

yup, why I added "on the pipe." ANY cooling is good.

The other thing is to invest in a Turbo Timer, which leaves the engine running for a variable amount of time after running the car. If you do what this woman did and just parked the car after a long hard highway ride home, 3-4 minutes is good. If you're running at 35 MPH or less, a minute or two will work. A lot of them are programmable and/or settable. You 'dial in' the amount of time to idle the engine, so if your trip to work is a long freeway ride right into the parking lot you set it for 3-5, and the easy cruise through the neighborhood on the way home is served by 1.