Mongo

I started the 928 today after about 2 weeks and heard a sound that i haven't heard in 2 weeks. Lately the car has made this sound similar to a growling underneath (sounds like a GRRRRRRRRRRR). when I rev the car it turns into a whine and then back to a growl...Also, on start up you hear like a chattering kind of noise from under the car but that noise dampens when it warms up and almost disappears....but the growling under the car is still there, it sounds like its coming from between the rear of the motor and the catalytic converter.....I've never heard this sound on any of our 928s we had before....what could it be???

(car is automatic by the way)
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Barry Johnson

Do you think its possible your cat pipes have come a little loose? That sounds like what mine does, and it definately whines in the upper rev range. Sounds like a real small turbo. Wouldn't that be nice . I noticed these noises (mainly the chattering/metal banging noise) after my gutted cats were swapped in. Sounds like a mechanic under there trying to get my attention to put out more money. Isn't that called the 928 check pen noise? Hehe, hope this helps! I'm just going to redo my exhaust anyway and use the Louie X crossover and custom 2.5" pipes all the way back to new mufflers in place of the mid mufflers. Yeehaw!

Mongo

I'll check those out as soono as I get back from work Barry! Thanks for the reply!!!! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

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Mongo

ok assuming worst case scenario.....again, would it be drivetrain related??? Like a torque tube???

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Barry Johnson

Does it have the same symptons regardless of in gear or not? If so, then I'd say its probably not a torque tube. A tt going out is a vibration you can feel in your butt that changes with speed. You said the noise is from the front of the car, so thats even more of a case for non-drivetrain related issues. Checked out the exhaust yet?

John Speake

Has the flex plate tension been released recently ? If not, that sound could be the crank grinding the crankcase !