MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Vibration between 2500-2900 rpm

After a complete 2 1/3 year restoration including an engine rebuild and 5 speed gearbox, I had my 60 Coupe on the road for the first time last week. I have a resonanance or vibration that can be seen by a vibrating interior mirror and other vibrations behind the dash, between 2500 to 2900 rpm. Below 2500 it's smooth and above 2900 it's smooth. I wonder if the engine rebuild (which was rebulit by the previous owner) is the problem. It's a 1600 bored out to 1622 + 40 thou and fitted with a lightened flywheel and front crankshaft pulley, same as an MGB.

Andy 60 Coupe (vibrating)
Andy Preston

There are many reasons for a vibration such as you have. The most common cause I have found for a similar vibration is the condition of the drive shaft U joints.


Mick
M F Anderson

Does it vibrate the same in neutral ?
Art Pearse

I suppose this vibration occurs while car is parked with tranny in neutral. So it would be the engine through the clutch pressure plate spinning ...plus the mainshaft of the tranny. I'm have no idea how much vibration you are speaking of. Some vibration is normal.
Have you removed the fan belt which would remove the possibility of the generator, water pump and fan causing the vibration. Can you hear any increase in engine noise when the vibration is the greatest?
I once used a glass of water placed on the dash to emphasize the vibration I was getting from the driveline. The car was firmly on jackstands while I ran the engine and went up through the gears.
Ray Ammeter

If the lightened flywheel was not rebalanced after machining, it could be the cause.
Art Pearse

Thanks for the ideas guys. I try disconnecting the fan belt tomorrow and also do the rev test with the car in neutral. I know that some vibration at some rev ranges is normal, I'll let you know.

Andy
Andy Preston

This thread was discussed between 28/04/2009 and 29/04/2009

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.