Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle

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Mon 27 Jun 2011 19:18
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - Smooth as silk

I bought this car 10 weeks ago it came with a 3 month warranty.It has developed a very high pitch whistle which is steadily getting louder on accelerating only.Any ideas what it might be and can I get it fixed under the warranty?

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Mon 27 Jun 2011 19:39
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - Peter.N.

Does the noise vary in pitch with accelerator position? Does it vary with road speed?

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Mon 27 Jun 2011 20:14
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - Smooth as silk

Hi there,yes the pitch gets higher with more acceleration as soon as the foot is off the pedal the whistling stops.

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Mon 27 Jun 2011 20:36
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - unthrottled

It's turbo whistle-all turbos do it-but some have better acoustic insulation than others.

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Mon 27 Jun 2011 23:14
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - Peter.N.

Agreed but if its very loud you may have a leak in a pipe near the turbo.

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Mon 27 Jun 2011 23:49
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - unthrottled

Wouldn't that be a hiss rather than a whistle?

On second thoughts, I'm inclined to agree. You normally hear a turbo whistles as it spools but when it gets up to speed the whistle becomes ultrasonic and virtually inaudible.

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Tue 28 Jun 2011 00:40
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - Peter.N.

Not necessaraly, if its on the output side the turbo noise will escape as well - try running one without the pipe on - depends how good your high frequency hearing is of course, mainly age related.

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Tue 28 Jun 2011 01:45
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - unthrottled

But wouldn't this be acompanied by loss of boost and a complaint about the turbo being slow to 'kick in' at low speed?

depends how good your high frequency hearing is of course

Pardon?

[cheek!]

Edited by unthrottled on 28/06/2011 at 01:45

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Tue 28 Jun 2011 11:04
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - Peter.N.

I speak from experience!

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Tue 28 Jun 2011 16:47
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - glowplug

A leak after the turbine stage - say at the joint of the manifold and exhaust downpipe would lead to serious whistling with no loss of boost, in fact the boost could peak higher and faster due to the lack of back pressure. This can also lead to boost spikes that can put the engine into over boost and place the engine into LOS (limited operating strategy) thus illuminating the engine management light.

Steve.

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Tue 28 Jun 2011 17:02
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - davmal
Had a leak on an inlet manifold owing to it distorting, the slight clearance turned the joint into a sort of reed (as in a clarinet). The whistle at higher powers was deafening.
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Tue 28 Jun 2011 20:08
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - unthrottled

Boost is controlled via the intake manifold pressure not the back pressure in the exhaust so you won't get boost spikes.

An exhaust leak leak tends to be obvious in a diesel because the pulses are quite strong even at idle so you would get a throbbing noise.

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Tue 28 Jun 2011 17:29
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - Smooth as silk

There is a loss of boost in lowest gear more so when driving of from standstill,don't know if this muddys the waters or clarifies my problem!

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Tue 28 Jun 2011 20:06
Land Rover Freelander Sport TD4 auto 55 plate - High pitch whistle - unthrottled

lag/spool up time are difficult to quantify from a stand still-which is why the two terms tend to get confused!

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