Engine has a rattling noise?? help :)

[Courior]

when the engine (1.0L K10 4 speed) has just started up and the choke cuts off and the engine is running at 8-900 rpm idle speed it sounds like someone is under the car shaking a spray can! you know that metal ball in the can sound? ive just changed the oil and checked for loose things (did a search and heatshields are a culprit) and found nothing! when the revs get above 1000rpm the noise goes completly. after the engine gets to its operating temp (about 3 mins after the choke switches off) the noise is much quieter. I have run the motor with the oil cap off and the rockers seem very quiet, the noise is deffinatly comming from the lower part of the engine. the only thing i can think of is that i noticed this noise after tightening up the alternator belt as i put a new one on a few days ago.. any help would be well appreiciated! (i got a lot of miles to cover tommorrow with a very loaded car!)

so my Questions are:
1. is it safe to drive as in im not causing further damage by driving it?
2. what the heck is making this noise!! lol

THANKS SOO MUCH!!
Courior

 

[paul_k10_Lx]

you havent left a socket or something in the bay have you ??

 

[Charlotte001]

Get the oil pressure checked also have the tappets checked

If the noise is loud on startup but quietens after a while especially when the engine is at operating temp it's oil pressure or oil (cheapo oil is a good one for killing pumps ie £2.50 from the superstore or the £6.50 from Halfords) If the noise is still there but quiet it's either the tappets or the bearings in the alternator. (I've just replaced the bearing in my alternator)

I doubt if it's bearings. If you've checked the heat shields if they're secure it might be worth checking to see if the bracket on the exhaust is loosening or the baffles in the exhaust (again cheapo exhausts are great for rattles) It might also be worth making a note of where you're getting your fuel from the wrong fuel will make a noise like marbles in the engine.

If you replaced the alternator belt it might be worth a look to see if the tensioner bolt is tight and not rattling. I'd be happy to drive the car, even though it's making this nice noise. If it were a socket it would bounce out smashing into the exhaust especially if it's a Plug socket (I did that today makes one heck of a bang)


Charlotte

 

[Courior]

charlotte, thanks for the comment. tappets are good and oil pressure is spot on (the light goes out VERY quick after starting) ... so yeah it seems to get better as the temp goes up pointing to an oil issue. but then you hit the nail RIGHT on the head with the marbles in the engine sound! thats EXACTLY how it sounds!!!! and since filling up the car has seemed to have a flat spot at around 1.5-2k rpm. my dad said it was rubbish fuel and now you mentioned it i think it might be that.. although the alternator bearings theory makes sense as i noticed the noise after i made the belt tighter (and as the belt gets warmer it gets a bit slacker taking strain off the bearings???) the belt has about 1/2 inch either way in the middle of the longest run so should be ok but maybe its too tight? i think were onto something lol.

PS: deffo not a rattle such as a socket, a stone, or a heat sheild