Engine knocking while running idle

[shah24]

Hello all,

I have recently bought a bmw 318i, 1995cc, 2007. Just came across the knocking noise while the engine is running idle. The car has 40,000 miles on the clock and it was serviced once at 21,000miles.

I have read various forums and came across two things that it could be the exaust flaps clicking or the head. I do not know much about engines so would appreciate any help.

Thanks in advance.

Shah

[shah24]

Anyone...?

[ian_cab28]

Hi,

When you say it knocks at idle revs, does it increase the knocking frequency if you increase the revs slightly, if it was a problem with the head I'd expect it to knock throughout the rev range or at least a fairly wide band. Sounds like some form of vibration to me? is that the 4 cylinder valvetronic engine?

Ian

[Speed addicted]

Check your spark plugs are tight, I had the same thing on a 323 coupe and the plug closest to the bulkhead was slightly loose. Not much but enough to make a quiet knocking noise at idle.

Check the cheap stuff first!

[phelix]

Apologies if I'm stating the blindingly obvious but have you checked the oil level?

And if I'm reading your post correctly the car has had one oil change in 40K miles and 3 years?! When's the next change due?

[BMWBen]

phelix said:

Apologies if I'm stating the blindingly obvious but have you checked the oil level?

And if I'm reading your post correctly the car has had one oil change in 40K miles and 3 years?! When's the next change due?

That's pretty normal for a modern BMW you'll find! Long life oil, don't you know.

[shah24]

ian_cab28 said:

Hi,

When you say it knocks at idle revs, does it increase the knocking frequency if you increase the revs slightly, if it was a problem with the head I'd expect it to knock throughout the rev range or at least a fairly wide band. Sounds like some form of vibration to me? is that the 4 cylinder valvetronic engine?

Ian

Ian thank you for your reply. It is the 4 cylinder valvetronic engine (N43B20). Well the metal clicking noise comes at idle but I cannot hear it when I rev the engine. I will check again and listen closely.

[shah24]

Speed addicted said:

Check your spark plugs are tight, I had the same thing on a 323 coupe and the plug closest to the bulkhead was slightly loose. Not much but enough to make a quiet knocking noise at idle.

Check the cheap stuff first!

Thanks mate, Yes I will get on with that before I drive it next time and see if it changes anything .

Edited by shah24 on Monday 21st June 22:28

[shah24]

BMWBen said:

phelix said:

Apologies if I'm stating the blindingly obvious but have you checked the oil level?

And if I'm reading your post correctly the car has had one oil change in 40K miles and 3 years?! When's the next change due?

That's pretty normal for a modern BMW you'll find! Long life oil, don't you know.

Thank you. Well I am also looking into the Service history as I do not have any other record so I will be calling the helpline to check if they have anyother record of the service. But in anycase I will taking the car for a full service as soon as possible.

BMW normally uses synthetic oil and they recommend to change it every 19000miles or when the car computer system tells you to.

[Heathwood]

Is it a knocking noise as per the original post or more of a metallic clicking as you later state? A metallic clicking noise at idle may just be injectors.

[shah24]

Hi guys,

I have been busy tracking the service history and so far there are two services. first one done at 21k miles and 2nd done at 39k miles. So I think the oil levels would be fine. It could be that the plugs are a bit lose or maybe something else. I still haven't had the chance to fully investigate by running the engine but will post the results in a couple of days.

Thanks .

[Neil.D]

shah24 said:

Hi guys,

I have been busy tracking the service history and so far there are two services. first one done at 21k miles and 2nd done at 39k miles. So I think the oil levels would be fine.

You have checked the oil level yourself right?

[shah24]

Neil.D said:

shah24 said:

Hi guys,

I have been busy tracking the service history and so far there are two services. first one done at 21k miles and 2nd done at 39k miles. So I think the oil levels would be fine.

You have checked the oil level yourself right?

Well I can only check this through the onboard computer which says it is fine. I will do a detailed inspection today.

[tony0889]

SO did you get it fix if so what was it i believe i have the same problem on a 93 325i. changed the oil and the fuel filter then i got this same noise

[shah24]

tony0889 said:

SO did you get it fix if so what was it i believe i have the same problem on a 93 325i. changed the oil and the fuel filter then i got this same noise

Hey mate,

Mine had an oil service recently as well but now I can only hear the noise when I listen to it very closely. I think you need to check the oil level first. It might not be the engine knocking just some sort of vibration. Listen to it closely and it might just be the exhuast flaps.

[Oilchange]

Let me get this right, you believe you can only check the oil level using the on-board computer?

Have you ever heard of a DIPSTICK!
You fking dipstick.

Some people shouldn't be allowed on the road...

shah24 said:

Neil.D said:

shah24 said:

Hi guys,

I have been busy tracking the service history and so far there are two services. first one done at 21k miles and 2nd done at 39k miles. So I think the oil levels would be fine.

You have checked the oil level yourself right?

Well I can only check this through the onboard computer which says it is fine. I will do a detailed inspection today.

[mike325112]

Oilchange said:

Let me get this right, you believe you can only check the oil level using the on-board computer?

Have you ever heard of a DIPSTICK!
You fking dipstick.

Some people shouldn't be allowed on the road...

I'm pretty sure that modern petrol BMW's don't have a dipstick...

Edited by mike325112 on Friday 16th July 14:00

[Vee]

Oilchange said:

Let me get this right, you believe you can only check the oil level using the on-board computer?

Have you ever heard of a DIPSTICK!
You fking dipstick.

Some people shouldn't be allowed on the road...

Did you think you were adding ANYTHING constructive ?

Do a bit of googling then perhaps apologise to the guy.
Since when do you have to know how to check the oil to be able to drive ?

Edited by Vee on Friday 16th July 14:03

[Oilchange]

OK maybe a bit short there apologies.

...

Edited by Oilchange on Friday 16th July 15:20

[BliarOut]

Vee said:

Oilchange said:

Let me get this right, you believe you can only check the oil level using the on-board computer?

Have you ever heard of a DIPSTICK!
You fking dipstick.

Some people shouldn't be allowed on the road...

Did you think you were adding ANYTHING constructive ?

Do a bit of googling then perhaps apologise to the guy.
Since when do you have to know how to check the oil to be able to drive ?

Edited by Vee on Friday 16th July 14:03

1st July 2008 I think.