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Discussion Starter #1
It never seems to end, after replacing bearings & belt on the zd30 (due to a day out which involved only 1 mud hole) the old girl was as quiet as a mouse.
We went down south the following weekend & would have done a round trip of approx 1000k's no hick ups other than seeing how hot post turbo temps are due to newly installed exhaust temp gauge. Another whole week of driving went by with no dramas, the new Beaudesert exhaust had been ordered then out of the blue the missus was leaving work when she said this squealing started, she kept driving & the noise disappeared (that or the radio was turned up) when I got home she mentioned it so I went out & started up the car to this almighty noise.
After approx 10 seconds the noise disappears then every time you tap the throttle it squeals & disappears. First thoughts were idler pulley bearing or alternator so I removed serpentine belt so no pulleys were turning noise still the same.
Removed turbo inlet elbow to see/feel end float rotation of turbo. Rotates smoothly doesn't seem to be rubbing & minimal to no end float.
Also thought maybe exhaust gasket. The only thing that makes me change my mind is, when engine is cold the noise remains constant & disappears once engine begins to warm up. Once engine temp is up a little but not higher enough to register on temp gauge the noise disappears other than when you dab the accelerator pedal or switch the car off then back on again.
I'm a little lost for ideas & intend to sleep on it. I have had a read through some of the other threads previously written & I appear to have an opposite symptom compared to what others have had where there noise starts once the engine warms up.
Look forward to reading some ideas unless anyone knows a reputable mechanic in Perth they'd be happy to recommend?

Cheers Gutd3L
 

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My 3 lt was the same for 3 days till she put a hole in #3 pistion,hope yours is not the same! it could be a crack in the exhaust manifauld with luck as it disapears when hot it could be and exhaust thing.
Cheers
 

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Discussion Starter #5
My 3 lt was the same for 3 days till she put a hole in #3 pistion,hope yours is not the same! it could be a crack in the exhaust manifauld with luck as it disapears when hot it could be and exhaust thing.
Cheers
This could be plausible also as I noticed a larger than normal volume of oil in the Provent 200 after only doing a 1000 clicks. Will look at doing a compression test also & hopefully see what comes up.
Next thing, where's best place to get rebuild kits?
 

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I've had squealing from the belt tensioner bearing which was fixed after the belt tensioner was replaced under warranty. When squealling started again i put it in to be replaced again during the next service. This time it was found to be coming from vibration of the airbox. I'd never have picked it, but it was fixed by having the airbox removed and refitted. Worth checking.

Your discription does sound like a cracked exhaust manifold though.

How hot did you let it run when obseving it on the EGT gauge? If it hasn't run super hot for any length of time i'd like to think your pistions are ok.

Hope it works out not too serious.

Grogey.
 

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Discussion Starter #9
back on the road....... just a matter of how long for???

The few things I found which look to have caused the squeal were front stud on exhaust manifold broken with one below not far from it as this sheared when removing exhaust manifold. I also found that the lower aluminium flange betwween the EGR & inlet manifold face was warped which wa sthe main culprit now I've had time to think about it.... Due to the noise I had a funny suspicion it had something to do with the EGR somehow just the way it disappeared suddenly once things started to warm up as if the EGR solenoid was switching.
I also ordered a new exhaust the day before this all started & have fitted it. As you could all probably understand I'm feeling a little nervous at the moment as the new exhaust has the car sounding quite different. Exhaust temps still seem to be getting up there with the quick lap around the block showing 400C post turbo. Will give it the 110 test soon.
 
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