Vibration under light acceleration at speed

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Rupert
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Vibration under light acceleration at speed

Post by Rupert » Thu Jun 11, 2015 12:39 pm

On the motorway yesterday and accelerating gently in 4th/5th gear I could feel a vibration. No vibration under full throttle or no throttle.

What could it be?

I found a thread on an alfa owners forum saying it could be worn drive shaft or CV joint, any ideas?

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mavada
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Re: Vibration under light acceleration at speed

Post by mavada » Thu Jun 11, 2015 12:57 pm

you could start checking the axles for play.
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SchrickRS6
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Re: Vibration under light acceleration at speed

Post by SchrickRS6 » Thu Jun 11, 2015 1:54 pm

I have vibrations when I lift off the throttle, from highway speeds. But I have been told a couple of my arms bushings are starting to wear one front and one at the back .....cant remember if upper or lower.
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J

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Shoppinit
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Re: Vibration under light acceleration at speed

Post by Shoppinit » Thu Jun 11, 2015 3:51 pm

Probably inner cv joint.

Could be prop shaft.

Might even be misfire.
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Re: Vibration under light acceleration at speed

Post by R5XVB » Thu Jun 11, 2015 8:53 pm

...might be a coil pack or plug (or combination of both and / or multiples on different clylinders).

The strong carry the weak at different input levels, if this happens cruising with light throttle input I'd be checking that lot first. Could be shafts but that should be worse at higher revolutions.

magpie21
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Re: Vibration under light acceleration at speed

Post by magpie21 » Sat Jun 13, 2015 4:58 pm

I had this exact same problem a month or so ago, i replaced the bushings etc which didn't cure it. Turned out to be the prop shaft in the end. All repaired at MRC.

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Re: Vibration under light acceleration at speed

Post by mavada » Sat Jun 13, 2015 7:07 pm

...but what happened with the propshaft? out of balance?
If you can't go to the track, bring the track to you.
Mugello Blue C5 RS6 Avant
Viper Tuning ECU/TCU
MTM Bimoto wheels 9,5 x 19 ET 30 LK 5x112 with 275/30/19 tyres
MTM exhaust system cat back 4-pipe with throttle valves in 2 pipes, control
Yellow Koni's
Porsche 959, gone but not forgotten.
Fight ALS disease https://www.youtube.com/watch?v=wGFDWTC8B8g

magpie21
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Re: Vibration under light acceleration at speed

Post by magpie21 » Sun Jun 14, 2015 12:06 pm

I'm not the most technical of people but the end of the propshaft pretty much disintegrated so every time I was accelerating the car vibrated. It wasn't noticeable at low speed but at 50 - 60 mph+ you could feel the vibration.

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Rupert
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Re: Vibration under light acceleration at speed

Post by Rupert » Mon Jun 15, 2015 11:31 am

Well, really weird, I was demonstrating the vibration to the wife on Saturday, convinced that it couldn't be a mis-fire because it didn't seem to matter what gear I was in, i.e. higher revs in 3rd at 70 the vibration was still the same freqeuncy as it would have been in 5th. Then on Sunday... no vibration. Surely if something is/was worn it wouldn't get better by itself?

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