Vibration at 3k revs?

[tuttle]

Have had my lovely mk1 1.8 for about 6 weeks now. Really incredibly & blissfully happy with it.
I have noticed slight vibration at 3-3.2k revs, and it seems rev specific rather than speed related. Unusually this is being communicated to me through the seat & through the left side of my bum! (No vibes ever at speed through wheel/pedals). I'm thinking perhaps this could be something to do with prop shaft/diff end of things. Anyone any advice?
Thanks in advance.

[Howard-]

I've noticed this on my 1.6, and it's what can cause heat shields to rattle. I've just put it down to resonance at certain frequencies/RPMs being transmitted through the body

[bluetone]

Rusted-through heatshield and/or catalyst shield in my experience = loose = rattles @ 3000-3500 rpm.

[paulmurr]

My car (2003 1.8iS) has done this since I bought it in 2006. I've had a garage put it up on ramps but nothing was loose so I just assume that it's a resonance thing. Keep it above 4k rpm and it's fine

[DennisTheMenace]

heat sheild on the down pipe from the manifold , mines grotty , keep meaning to cut it off .

[tuttle]

Thanks all. A relief to hear that it's unlikely that my prop shaft is unlikely to self destruct & shove itself up my @rse at speed. That would make for a bad day!

[bluetone]

DennisTheMenace said:

heat sheild on the down pipe from the manifold , mines grotty , keep meaning to cut it off .

I took a dremel to mine; twas a complete biatch to cut off the remaining securing section = difficult access and dremel cutting discs weren't really up to the job. I lost count of the number that broke.

[GravelBen]

My MX5 rattles and vibrates at any revs and any speed.

[MX-5 Lazza]

GravelBen said:

My MX5 rattles and vibrates at any revs and any speed.

That'll be all the gravel you've picked up in the heat-shields, arches, engine tray etc rattling around

[snotrag]

FWIW - it wont be the Diff/prop if its matching engine speed.

They turn at road speed, there after the gearbox.

It could be one of many things, you get a different noise every day in mine.
Heat sheilds are a very common one.

From personal experience, you can spend hours fannying around under axles stands trying to work it out, but if you bung the local garage a tenner, its dead easy to get the car up high on a ramp, and you can easily walk underneath with a much better view.

[bluetone]

Indeed. Drivetrain woes more likely to sound like a whine or a grinding noise rather than a rattle