Car chuckling when started

jezzer

Folks, a 2.0 ltr petrol bmw 3 series chuckles and rattled when started but when revved it turns over ok, what would be causing this? it has only recently started

Supergurrier

Did you put helium in tyres by mistake ?

Failing that sounds like a belt worn or the like.
Does the sound increase with the engines rpm when you rev it or is it more of a constant whiney sound ?

Rattle on startup on some cars can mean timing chain tensioners worn or broken too(not sure if 2 litre bmw petrol 4 cylinders are chain or belt)

jezzer

Supergurrier wrote: »

Did you put helium in tyres by mistake ?

Failing that sounds like a belt worn or the like.
Does the sound increase with the engines rpm when you rev it or is it more of a constant whiney sound ?

Rattle on startup on some cars can mean timing chain tensioners worn or broken too(not sure if 2 litre bmw petrol 4 cylinders are chain or belt)

no it just happens on start up, when i rev the engine it goes back to normal, if left sitting there it sometimes sounds like its goign to either cut out or go into overdrive but as i say once revved it ticks over as normal?

Supergurrier

jezzer wrote: »

no it just happens on start up, when i rev the engine it goes back to normal, if left sitting there it sometimes sounds like its goign to either cut out or go into overdrive but as i say once revved it ticks over as normal?

Squealing would be a belt(aux belt/alternator belt)

Rattling would be chain or chain guides damaged.

biko

Chuckling means laughing. I suppose what you're try to say is that the idle is rough?
Next time, look at the tachometer (rpm counter), does it move during the rough idling?

How old is car?

I'd start with low hanging fruit -
check oil level, fill to max
toss fuel system cleaner into petrol tank
clean MAF and throttlebody.

jezzer

biko wrote: »

Chuckling means laughing. I suppose what you're try to say is that the idle is rough?
Next time, look at the tachometer (rpm counter), does it move during the rough idling?

How old is car?

I'd start with low hanging fruit -
check oil level, fill to max
toss fuel system cleaner into petrol tank
clean MAF and throttlebody.

2002 no, revs stay down...yes rough idling is right

Alanstrainor

jezzer wrote: »

2002 no, revs stay down...yes rough idling is right

So is it a 318i or a 320i? As biko suggested I'd start with the basics and work from there. Check oil level first.

jezzer

Alanstrainor wrote: »

So is it a 318i or a 320i? As biko suggested I'd start with the basics and work from there. Check oil level first.

it is buring/leaking a small amount of oil and needs to be topped up every so often but i only topped it up on sat? 318

Alanstrainor

jezzer wrote: »

it is buring/leaking a small amount of oil and needs to be topped up every so often but i only topped it up on sat? 318

There's really lots of things this could be. If the rough idle persists even when the engine is warm you couldn't rule out things like the fuel pump, or perhaps even vaccum leaks such as from a rocker cover gasket. Hard to know to be honest...

jezzer

Alanstrainor wrote: »

There's really lots of things this could be. If the rough idle persists even when the engine is warm you couldn't rule out things like the fuel pump, or perhaps even vaccum leaks such as from a rocker cover gasket. Hard to know to be honest...

would it be anything serious that would need to be checked asap?

pa990

A Coil pack is on it's way out

jezzer

pa990 wrote: »

A Coil pack is on it's way out

is that serious?

pa990

jezzer wrote: »

is that serious?

No, each spark plug has one.
You unclip and remove the coil pack to get to the spark plug.

Extremely simple to do, no expertise required.

It's just a matter of finding out which one you need to replace.

jezzer

pa990 wrote: »

No, each spark plug has one.
You unclip and remove the coil pack to get to the spark plug.

Extremely simple to do, no expertise required.

It's just a matter of finding out which one you need to replace.

great cheers for the advice