'whistle' under acceleration from 328 m52??

[addsvrs]

Always happens, after turning down a newer car last week i've noticed a 'whistle' sound coming from the engine under acceleration (e36 328). Ive also had a few times high uneven idling (if that makes any sense). Wont beable to get to my local garage until wednesday so anybody have any ideas?? thanks in advance

[4rephill]

addsvrs said:

Always happens, after turning down a newer car last week i've noticed a 'whistle' sound coming from the engine under acceleration (e36 328). Ive also had a few times high uneven idling (if that makes any sense). Wont beable to get to my local garage until wednesday so anybody have any ideas?? thanks in advance

It could be a vacuum leak leak somewhere. The problem is the pipes on the engine get old and brittle due to the heat in the engine bay and split (usually where you cant see it!!!). One way to check is to spray carb cleaner around the intake pipes while the engine is running and see if it gets drawn in anywhere (be aware that vacuum leaks can be an absolute br to track down!).

Also, it's quite common for the idle control valve (ICV) to become dirty and to stick causing an erratic/high idle speed. There's info on the net as to how to clean the ICV if you feel you can tackle it.

Best of luck with it, I'm currently battling My 328i cutting out every now and again when coming to a halt!. Can't find any vacuum leaks (doesn't mean there isn't one though!), pipes all look ok, ICV is fine, and it does it randomly out the blue after months and months of running fine!.

[S3_Graham]

My car had a lumpy idle. Replaced the intake pipe, the icv valve and the pipework with it. Was £250 at my local Indy but ran lovely afterwards! It was found with a smoke generator!

[texasjohn]

My 130i does this too. I took it in under warranty and they replaced the alternator.

Still doing it. I told them I thought it was a leak in the intake system too!

[addsvrs]

Well did the bloke thing of looking under the bonnet today (not really any idea of what i'm looking for lol) and found the airbox was loose from the box to the intake pipe, re-secured and the whistle seems to have gone (touchwood) just the idle to look at now, although will let someone with a bit more knowledge do that. cheers for all the advice so far...