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rattling noise whenever i tried to go over 3000 rpm

10210 Views 15 Replies 12 Participants Last post by  StevenDriscoll
i get rattling noise whenever i tried to go over 3000 rpm mark.....everything is quite till 2900rpm then...the noise comes from the engine (?)...

once i go over 3000...the noise stops..

this is quite annoying...did anyone experience similar stuff??
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I have the exact same germlin!!! I finally got the tech guy to acknowledge that he heard the sound too. He said he was even able to duplicate the knocking or rattling noise on the Operation Manager's IS 300.

"Ok, so what are you guys going to do about it?" He said basically there's nothing they can do since I already had the ECU re-program/update. He offered to do the TRAC update but specified that this update was not intended to deal with the rattling noise I was experiencing, therefore, he wasn't sure if it would fix the problem. Another possible downside to getting the TRAC update is that the car might be a little more sluggish off the line since the TRAC update is designed to smooth out the gear changes (transmission).

I was afraid to get the TRAC update since there's no telling what the outcome would be and I couldn't change it back to the way it was if I didn't like it.

While the knocking/rattling doesn't seem to effect the performance all that much it is extremely annoying as hell! If anyone out there knows how to solve this problem please let me know.
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Heat shield? Like what a screw is lose somewhere? Is that something I can check/fix myself or would you recommend taking it to the dealer?

As added info, mine occurs under hard acceleration from a standstill - from 1st to 2nd or 3rd gearshifts in either shiftmode. The noise appears to go away (at least a little bit) after continued hard driving - 30 mins or more........
The tech guy who drove my car didn't think it was the heat shield. He said the engine was SPARK KNOCKING???? But it's true the noise makes more of a rattling sound than anything. I've tried leaving the car in ECT mode for a couple days to see if that helps..... no dice! The dealer called me today and said they were going to try and get a regional (south) tech rep to come out and investigate the problem. BTW this problem started happening at approx. 4,000 miles.
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