Engine/Transmission Vibration at 1000-1500 rpm under load

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elbirchos
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Thu Oct 18, 2007 7:02 pm

In any gear at any road speed I get a fairly coarse vibration (I can just about 'see' it in the rear view mirror) between 1000 and 1500 rpm, with no problems whatsoever at higher engine speeds.

The more throttle, the worse the vibration.

It doesn't gradually tail off after 1500 rpm - there's a definate change at that speed from vibration to no vibration.

The engine mounts 'look' fine (I can't see any blatant degradation or damage) but the car is now 23 years old and there's no mention of them having been replaced in the history.

Any ideas?
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elbirchos
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Fri Oct 19, 2007 6:09 pm

anyone?! :?
daimlerman
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Fri Oct 19, 2007 7:26 pm

First thoughts are propshaft centre bearing,any play in it?
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Martinaston
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Fri Oct 19, 2007 7:52 pm

Check the dizzy cap for worn electrodes, it may be shot to bits and when at 1000rpm the gap is too big for the spark to make it across. Once at 1500rpm the timing may have changed so the spark is contacting a different part of the electrode.
If it looks OK then you could try pulling the HT leads one at a time to see which one is breaking up.
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