Engine noise/rattle when starting up??

[ecswtrav]

Hi there,

My 2000 2.7 Boxster has developed a strange sound whenever I startup the engine from cold. The sound also happens on occasion when the car has been warmed up.

On starting the engine I get a grinding, maybe rattling type sound come from the back where the engine is - it doesnt stay on permanently, only for a few seconds and comes and goes. Initally I thought maybe the exhaust was loose but then when the car heats up the sound cannot be heard so ruled this out. The sound also has varying volume levels sometimes being rather loud.

The sound will also be present on and off when driving until it warms up. The type of sound is difficult to describe and seems to be doing no harm. Its been present now for a few weeks - I was kinda hoping the cold mornings were at fault but im not so sure why this would happen and why it still happens on very mild mornings?

Any help or suggestions would be gratefully appreciated as Im debating sending it to the garage and don't want to be conned into any expensive repair jobs when it may not be needed.

Thanks