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Discussion Starter · #1 ·
Firstly, this just had to happen a few days out from a big road trip :/

I was taking a corner in second gear on full boost, (driving hard) TRC light flashing then BANG! engine suddenly revved to redline.
Stopped car, inspect, nothing. Start car, full boost still alive but now a grinding/rubbing sound can be heard from under car. :(
I still have full mechanical operation, power and gear usage.

Any ideas ?
 

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Did you lose AWD? Sounds like you may have slipped the front wheels and transfered all torgue to the rear and broke the driveshaft or transfer case (do these have a transfer case). That would explain the sudden rev to redline.

Im not sure how the AWD in these cars works. I stay away from it. But I used to be a driveline engineer on AWD trucks and SUVs. It was possible under hard driving to transfer all the torgue to the front or rear and blow **** up. Usually happened on ice or in loose gravel/sand.
 

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Losing the load from the rear wheels while having no traction on the front would cause a sudden rev to red line like that, and material floating in the fluid in the VC could make some noise.

Edit: Removed bad info. Some of it anyway.
 

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They say to find a good loose surface (all that beach sand?) and nail it and look for slippage to determine whether you have any torque transfer to the back.
 

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How much power are you putting out now? Non-modded AWD cars never need to worry about the angle gear, but the Rs do. I wonder....
 

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Discussion Starter · #9 ·
Need specifics to when the noise happens. While turning / moving or also when just sitting at idle?
nothing at idle.
I can only hear it when driving, it gets louder on throttle and you can hear it winding down off throttle.
Nothing turning. I inspected all rotors and drive shaft. It sounds like something (like a rock) is wedged on the driveshaft and is rubbing.
 

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How's the car doing now? Still have the noise coming from under the car?
 

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Discussion Starter · #13 ·
How's the car doing now? Still have the noise coming from under the car?
A few interesting developments.
Turns out there was a drainage grill on the road at the exact point where the loud bang came from - so that HOPEFULLY explains the loud bang. I have experienced noise when driving over these in the past.

This morning we put the XC up on the hoist to inspect but nothing jumped out at us but a few oil leaks. New seals going in today. As per the noise - we suspect transmission oil is low causing the slight rubbing sound. As Murphy's law hates me, the noise hardly appeared when the mechanic took the car for a dive, thus making it difficult to diagnose. Plus having the only manual in Perth doesn't help.
Will find out later today what to story is. I still feel its something in the CV shaft area - like a bearing has come loose.
Apart from that, car drives fine. No problems.
 

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Sounds like the problem is emanating from the transmission and/or drive shaft area. Suspect that it can only be solved one by one. Last resort may have to take it apart and check the internals.
 

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I just reread my edited post and it wasn't clear. That's what I was trying to say. =P
 

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So after a day of inconclusive diagnosis we have confirmed I now have a FWD XC :p
Doing skids and TRC light flashing when boost kicks in confirms this.
I remember that feeling... Welcome to the spline stripping club :) lol. Hopefully your extra power didn't grenade your Angle gear too :(
 

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That's some balls. Pics of the carnage? Sounds like you're going to be whippin' a FWD XC for awhile...
 

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Now you can buy a mellow yellow C30 and make me really jealous?
 
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