rough idling

[top_driver]

my car is under performing and idles quite rough with the delay of the revs dropping, i have a list of things that it could be, im looking to have it narrowed down, from, leaking pipes from somewhere, egr valve, mass airflow metre, or something that wouldnt show up on the fault codes

[flump1]

fuel filter ?

[TWR]

Take the plastic tappet lid off & check your plug leads Top, they can be very hard to remove & there is every chance some has damaged the lead itself. has the car just started doing this?

[top_driver]

maybe, i could try get a new one

[top_driver]

yes, it was at one point running really smoothly, now it just sounds rough, i have new Bosch spark plugs in got from ebay for 80 euro, what would i be checking for on the leads

[TWR]

At the end of the lead, the part that goes onto the plugs, at times can be very tight to remove, there maybe damage done there, if you do change these just insert a BIT & only a BIT of Copper Grease where it connects to the plug.

[top_driver]

it started to become rough before i changed the spark plugs, i just changed them because i thought it was due, is there physical signs of damage

[TWR]

No, did you get a problem removing them? did you pull them by the lead? if so thats your problem.

[Zacs-Master]

If it's a golf it could be the EGR

[TWR]

Its a E46 Bimmer Zac.

[TWR]

With your service, did you change the In-Line fuel filter Just underneath on the N/S/ Top, this gets missed by a few.

[Hopkirk]

Change the oil, and give it a long hot run.

[shooty]

Mass air flow sensor.
I am not saying it is this, but a good place to start. You would not beleive what a difference this component makes. Cleaning with sprays will not bring this back to life.

[top_driver]

oil has been changed and engine was flushed, hopefully i will have myself a new sensor soon, what's an in-line fuel filter, either way it wouldn't have been changed, i could change it though

[TWR]

This Petrol filter is under the car, if you look beneath the N/S jacking point you may be able to see it but the car need to on Ramps or better still, access to a pit.