My 54 plate Octy vRS has started making a nasty noise when cold. The engine starts fine, but as soon as you put the engine under load when starting to pull away, a nasty mechanical noise can be heard from the engine. It's like a rattly grinding noise, like a rotating part is catching on something. When it happens I dump the clutch and try and pull away again. Nine times out of ten it won't do it again, but sometimes I may have to do a number of attempted pull aways until the sound is no longer there. The power produced by the engine is always fine, but if I'm being super critical, the idle may be a bit lumpy. When idling under no load, the noise is not there.

Any ideas?

Thanks

Aux belt slipping maybe, thats like a high pitched squeek normally

It's not a high pitched squeak noise. It's more of a metalicy grind / rattle.

I'm thinking CAM belt tensioner

I'm thinking CAM belt tensioner

In that case drive no further get it looked at asap,

Can't see it being the Cam belt tensioner, as that would presumabley rattle all the time, with quite devistating conseqences! After a couple of pull aways, the car is fine for the rest of the day. It only does it when starting from stone cold.

flywheel breaking up? or a gearbox problem maybe

Maybe the Charcoal cannister??? That can sound like a ticky noise

There are a number of possibliites that would really need a better look.

Worn cam followers - i.e they take a longer time to prime with oil, so on cold start they will be noisy and gradually prime with oil and become quiter. Maybe changing oil and running a better grade could help.

Also oil pick up pipe blocking up(lower engine / sump) is a common problem that when partially blocked will starve oil to head and cause rattling/noisy follwers and result in issue above. New pick up pipe is needed (not too dear) in that case.

Injectors make a tappy noise also and mine are quite noisy, but these tand to stay noisy and do not go away so probably rule that out.

Edited 12 January, 201115 yr by Bowders1

Loose CAT shield?? Mine does this as there are only two bolts left holding it on and it rattles around at certain RPM...?

Loose CAT shield?? Mine does this as there are only two bolts left holding it on and it rattles around at certain RPM...?

Yeah mine sometimes rattles at certain rpm's too. I've revved the car while underneath it, so confirmed it's the cat heat shield. It only started this winter so I suppose it's had a good innings. I'm waiting for it to drop off now!

I'll actually probably remove it next time I'm under the car. Just don't park in a straw lined stable after a long drive.....

Maybe the Charcoal cannister??? That can sound like a ticky noise

There are a number of possibliites that would really need a better look.

Worn cam followers - i.e they take a longer time to prime with oil, so on cold start they will be noisy and gradually prime with oil and become quiter. Maybe changing oil and running a better grade could help.

Also oil pick up pipe blocking up(lower engine / sump) is a common problem that when partially blocked will starve oil to head and cause rattling/noisy follwers and result in issue above. New pick up pipe is needed (not too dear) in that case.

Injectors make a tappy noise also and mine are quite noisy, but these tand to stay noisy and do not go away so probably rule that out.

Your suggestion of the pick up pipe being blocked is very plausible. I think the noise is from the head area. If I wait a minute or two and try another pull away, then the noise is usually not there any more. Presumabley by this time the CAM followers will have primed and thus no noise. Is it just a case of removing the sump and disconnecting the pick up pipe?

Thanks

Your suggestion of the pick up pipe being blocked is very plausible. I think the noise is from the head area. If I wait a minute or two and try another pull away, then the noise is usually not there any more. Presumabley by this time the CAM followers will have primed and thus no noise. Is it just a case of removing the sump and disconnecting the pick up pipe?

Thanks

Yes , quite a easy job