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Discussion Starter #1
I have had my Elise 111R for 3 years now and have had a really annoying buzzing noise around 3000 rpm. This metallic rattle was greatly reduced when I fitted the LETSLA a while ago. But I have just fitted various engine mods prior to getting the BOE Rev 400 kit and the E153 gearbox conversion. And even with all new linkages and a brand new gearbox this crazy annoying noise had returned. Anyway I looked to what it could be and found that there is a little slack in the crossgate lever where it meshes with the inertia weight arm and the small plastic "thingy".
I decided to add a weight to this arm to change its resonance frequency, this was simply a lead fishing sinker bolted to the arm. QUIET AT LAST.
I hope this may help someone else out there.
 

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I have a 3k buzz on an 07 Elise with no modifications to the shift mechanisms. Does the part in this photo exist on my car or is it an aftermarket part? Can't find anything that looks like it in the parts diagram. Diag shows "Lever, control shift" as key #23 that looks like maybe is has a counter weight / ballast / etc, on top. I sure would like to have such an easy cure as this. Anybody know?
 

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Richard, do you have any more pics you could post, or circle that part in a parts diagram? Thanks in advance.
 

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Discussion Starter #6 (Edited)
What you are seeing in the original photo is the crossgate lever with a small hole drilled through it and a lead fishing sinker bolted onto it. It will look a little different on the stock setup than mine as this is the E153 gearbox conversion. This is down under all the pipework above the gearbox. The cross gate lever is the one that is the most forward of the two levers. If you remove the little retaining clip and the cable off it you will soon see how it is loose and can rattle at certain frequencies (3000-3500 rpm) that is why making it heavier has fixed the problem. I did this with the intake removed while changing superchargers. You can drill the hole with the gearbox and linkages in situ with the intake removed.
Look up crossgate lever and you will find a diagram of what I mean.
 

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My 3k buzz was the alternator. The hole for the bolt, holding it to the motor, was "wallowed-out" and it buzzed between 2900 and 3200 RPM.

BTW, I have the BWR 1.0 supercharger setup, where the alternator is moved to the back.
 

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Discussion Starter #8
Just to follow up, I had the noise return a bit a while ago and found that the bolt tension had slackened. I tightened the little bolt and the noise dissappeared.
 

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I also noticed some wear on the metal cylinder that interfaces the cross gate lever to the transmission shaft. I always thought the "plastic thingy" was the interface there--it's not. It's just a dust cover or something. The metal cylinder is what contacts the transmission shaft. I was very excited to see there was metal-to-metal contact there and a little play, so it clicks when you move it back and forth. I figured that play and metal-to-metal *had* to be it...

No luck! I machined a Delrin cylinder to be a very light interference fit--no play, and it's plastic so no clicking if there was.

Not even the slightest change in the noise, so that's definitely not it...
 

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Discussion Starter #11
Thanks for the update...

I tried fixing a weight to the crossgate arm and unfortunately not a bit of difference...
Ah well good try, it evaded me for some years so I hope you are able to run yours to ground.
 

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I have had my Elise 111R for 3 years now and have had a really annoying buzzing noise around 3000 rpm. This metallic rattle was greatly reduced when I fitted the LETSLA a while ago. But I have just fitted various engine mods prior to getting the BOE Rev 400 kit and the E153 gearbox conversion. And even with all new linkages and a brand new gearbox this crazy annoying noise had returned. Anyway I looked to what it could be and found that there is a little slack in the crossgate lever where it meshes with the inertia weight arm and the small plastic "thingy".
I decided to add a weight to this arm to change its resonance frequency, this was simply a lead fishing sinker bolted to the arm. QUIET AT LAST.
I hope this may help someone else out there.
I have had a really annoying buzzing noise around 3000 rpm...and my car is a brand new exige with under 5000KM's ..thanks for the advice
 

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Worth checking this bracket - seen more than a few of them cracked - a very annoying drone/buzzing when it's gone:
Can you see this bracket pretty clearly from under the car with the diffuser panel removed?

On another note... Does anyone know how much "play" there should be where the cat meets the header? Meaning, I noticed that with my exhaust removed, the cat/pipe can pivot up and down a lot and a little from side to side. It doesn't seem loose at all, but more like a ball joint. I assume this allows the engine to shift around a bit without damaging the cat, exhaust, brackets, etc?
 

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Discussion Starter #15
I have my engine and gearbox out for a rebuild so here is a photo of my "fix" I welded a few washers together as the lead was too soft and kept loosening. A couple of times in the last few years my noise returned. Each time it was because the weight became loose.
 

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This may be a one in a thousand chance for those with a buzzing problem. I took off the plastic spark plug cover to paint it and I noticed that a buzz that's been haunting me for a year disappeared. The cover's going back on after paint but I'll experiment with tightening the bolts and check the plastic's not interfering with anything else, including the engine cover.



-Jerry
 

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Annoying buzz, intermittent.
I moved the small panel just in front of the windshield and it disappeared.
One of the two that cover the front outside.
Sam, with the dirty elise
 

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Another source of annoying buzz can be the rear license plate. Affix it with "euro style" license plate bolts both top and bottom and it will solve it. They typically only have bolts in the two top holes, so the bottom vibrates like crazy.
 

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My buzzing was a bit louder than a drone, but was happening around the 3k mark. It was the heat shield on the exhaust tip. Wedged a small piece of metal in there and no more buzz at 3k.
 

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I had a buzzing problem a few years ago. Are you sure it's not coming from somebody's purse!
 
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