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i have an 97 sri turbo and recently ive noticed it whines when i accelerate, sounds just like when you get alternator interference with your stereo but its defiantly coming from the engine. alternator going bad? or cam belt?

its not constant, seems just when turbo is on boost, or just when under a certain load maybe, if i accelerate slowly it doesnt really do it, but when on boost or up a hill for example its obvious

Could just be your turbo whistling?
Mine whistles a bit, sounds like a whine when inside the car.

has it become louder suddenly or always been like that? any loss of power?
EDIT: any smoke when you accelerate hard on boost?

I would agree, its probably the turbo, take you foot off the throttle when it does it and if it stops its the turbo. Could be the one of the pipes has come loose allowing the sound to escape.

Peter

Would the sound not also stop when i stop accelerating if it was the alternator? And i don't think it used to do it as that's why im suddenly noticing it and worrying

The alternator is being driven all the time the engine is turning, even down hill, the turbo is only spinning fast when you have you foot down fairly hard, you can play a tune on the turbo by changing the throttle opening, going down hill the turbo is doing very little. Its driven by exhaust gas so it speed is dependent on the amount of fuel you are burning.

Peter

So what would cause my turbo to start making this sound other than a leaking pipe?

Could be leaking boost, some boost leaks will sound like a bit like a party blower.

Simple check would be to park up and rev the engine to steadily increase to, say, 3500prm and see if the noise is there, if not then it is only happening under load which would point to a boost leak, turbo wear, or some issue in the transmission like low gear oil or worn bearings etc.

Sometimes boost leaks are evident by an oil leak as oil is carried over in the air stream from the turbo. Have a good look at the intercooler first as these did used to fail/crack.

If there has been any reduction in performance since the noise started, it could be as welly says a leak in the high pressure side including the intercooler, or it could be that you haven't noticed it before or low blood sugar.

Peter

Just a quick note..

A boost leak sounds more 'whooshy' then 'whiney' , and there may be oily residue at the leak point.

When the weather is warmer I have my passenger window down a bit for fresh air, and when traveling in a built up area my turbo seems much louder as the sound bounces off buildings etc.

I like the sound..

As others have said, the alternator, power steering pump and air-con pump run off the aux belt, so this noise will be heard even on tickover albeit a bit quieter.

Not 100% sure on petrols, but you can safely run diesel engines without the aux drive belt to eliminate some of the possible culprits, (alternator, power steering, a/c compressor, idler/tensioner).

GingerMagic wrote: I like the sound..

It's more noticeable without a cat.....

Doggy wrote:Not 100% sure on petrols, but you can safely run diesel engines without the aux drive belt to eliminate some of the possible culprits, (alternator, power steering, a/c compressor, idler/tensioner).

I would imagine that the computers might get a bit upset eventually as the battery is drained down. If another car was hooked up to the battery it might be a bit more forgiving.

FWIW, I noticed a bit of a whine on my 306DT just before the power steering pump failed. From the time I heard the noise until the pump literally fell apart was around 25 miles. As I was heading home at the time, I decided I would sort it out next day. Battery held up fine for the remaining 25 miles (around 30 mins) or so with headlamps on.

listened again tonight, doesnt seem to change pitch when it boosts more, just seems to whine then stop when i come off the boost, strange.