Rough Idle?

[Paul James]

Hi guys

My 2004 318i sport has 35,000kms on it and its the 5 speed semi auto.

When at idle it seem to be a little rougher than what i would expect - I have only had the car for a week as i purchased it used.

the revs dont jump around or anything like that - just wondering if thats the nature of the car and whether its normal or a known issue on the e46 318i.

Thanks

 

[Average Jae]

what does the car idle at?
i wonder if you are just going through, "i just bought this ride, and it MUST be perfect"syndrome. i still have it after nearly 4 years i get loud shrieking noise during a cold start up. (i found out its the infamous secondary fan, but i'll have to talk to my SA about lubing it or something..)

so just one question, bunch o babbling w/out real substance ^^; not much of a technical guy..

 

[Doughnut]

Does it do it only while the air-conditioning is on? if so it could be the a/c idle varying switch or if it does it all the time could be a simple issue, such as the spark plugs, fuel filter, try simple things before thinking you need an engine rebuild.

 

[William330]

Could be cheap gas, too.

I believe BMW recommends Shell, BP, and a handful of other gas stations who serve higher quality fuels.

My baby doesn't like Exxon gas at all, runs rough and pings.

See this article:


Fuel quality declining, auto industry asserts
Half of gas pumps tested did not meet minimum for detergent content, study finds
http://www.jsonline.com/story/index.aspx?id=283160

 

[Average Jae]

wow, it actually pings? there goes my theory on knock sensors.. ^^;

 

[tazza0712]

I haven't really experienced rough idle, but I do know it doesn't like cold starts. Get a really strange noise whenever it's started on a cold morning, lasts for about 30seconds and then disappears, service manager says it's normal and gave me a reason I can no longer remember. As far as fuel goes, I always use Shell V Power, or BP/Caltex equivalent if Shell isn't available. Maybe that may make a difference if you're not already using it??