Engine rattle at about 2000rpm

[09simpss]

got nova gsi 1.6 8v and at about 2000-3000rpm it makes strange rattle coming from inside engine. drives fine and still pull well.
any ideas?
crank big ends shells?
hellppp :)
steve

[Will F]

Shells probably - does it 'rattle' if you feather the throttle and hold it around 3k?

I wouldnt drive it too far - can eventually damage the crank

[09simpss]

yes exactly that and when first start up!
head off?
steve

[mowgli]

it could just be wear & tear. get the rocker cover off & check out the cam & followers, and maybe do a compression test to see if its any good

[Will F]

Compression test or visual inspection of the cams wont tell you anything.

You need to get the sump off and take the caps off and check that a bearing hasnt picked up or is excessively worn...

[09simpss]

been told its shells in crank...
does this sound likley?

[chimp007_uk]

Hard to say from the brief description. How loud is the rattle?! The RPM range you say is could be pointing towards detontation, when the engine is under load. Something else to think about... Get a timing light on it.

[mowgli]

Compression test or visual inspection of the cams wont tell you anything.

You need to get the sump off and take the caps off and check that a bearing hasnt picked up or is excessively worn...

the engine is 20 years old minimum. it will have loads of wear,

shells, crank, bores, piston skirts, cam lobes

the followers will be in need of cleaning up too.

the oil pump might not be supplying enough to keep the followers pumped up at low revs.

OP does the oil light stay on when you start it 1st thing in the morning?

[09simpss]

when first start from cold it rattles and oil light flashed and rattle stops oil light stops flashin,
then under reves it rattles, but when driving it still rattles but not as bad as just reving from stationary.
if that makes sence.

[Will F]

As said it is 99.9% your bottom end/shells/bearings (whatever you want to call it)

You wont be able to tell this until you take the sump off and look at the shells as I mentioned above.

It could have been caused by a drop in oil pressure or just excessive/uneven wear.

And Mowgli - if you have had a bottom end rattle - its quite a distinctive sound - the followers would only rattle/tap if the oil pump was screwed and that would rattle throughout the rev range and get louder, the higher the revs.

[MK999]

top end rattle will be half the speed of a bottom end rattle, and sound something like "a squirrel having a **** in a biscuit tin" is the best metaphor I've heard. Bottom end rattles sound more 'hidden' unless it's top end conrod bushes which can disguise themselves as top end.

Either way it's tear apart time because it could be anything from a list of hundreds of things, just check the exhaust gaskets first... because you wouldn't believe the kinda squeaks rattles and roars they can make when the gasket becomes a vibrating reed.

[09simpss]

ta lads

[09simpss]

Bought shells now gonna do them this weekend will let you know hoe i get on...

wish me luck ;)

[MK999]

just doing shells without getting the crank out to be measured/inspected is pointless, if the bearings have gone far enough to rattle chances are the crank is undersized/damaged.

[09simpss]

aye well been to few garages and they said just to put shells in as only just started making noise.

[Will F]

I agree - you should be able to do a reasonable job diagnosing condition in situ though - if they are scored for example, then obv need to be pulled apart. (unlikely though as you would be getting a knock too)

You may get away with it tbh - when mine was rattling, I did around 300 miles like it and the crank was fine...

[09simpss]

Thats what i like to hear Will!!!! haha!

[pottersrebel]

edit topic moved on alot since i finally posted so no longer relavent