BMW 325i E46 Rough Idle Popping Sound

[kokaxxx]

Change AIR FILTER or check MASS AIR FLOW SENSOR thats what i have done and now it's all GOOD

[triniguy99]

There's one last question i need to bother you about: I noticed that if I start up (experience rough idle, erratic RPM like you did) and wait a few minutes for the temperature to reach the typical mid-level on the coolant gauge, then switch off the engine, then start it up again, the car works like nothing was ever wrong! Was this your experience as well? Thanks..

[thenewserver]

hi ,I have the same problem .

can u tell me what exacly what i have to change

thankyou

[trinjaminternational]

@thenewserver - see my last comment below - Oil Separator Valve

[JCruzify1]

Thanks for the update. But did you have any idling problem? My e46 has rough cold start and stalls when put to drive. Did you have that happened to you?

[trinjaminternational]

@JCruzify1 - No, all idling issues were resolved with the fix above thankfully. I haven't experienced any cold start issues when putting in drive before.

[trinjaminternational]

Popping sound is not coming from the DISA unit but actually from under the intake manifold where my hand is (Oil Separator Valve is located under the manifold in this location as well). I've cleaned the ICV, did the DISA RTV Sealant DIY, checked intake hoses for cracks and tears, etc.

[trinjaminternational]

@trinjaminternational

Just an update. The fix for this was to replace the Oil Separator Valve and All Hoses that it connects to (makes sense since they are in difficult to reach locations and you will be doing the same job of removing parts to get to them if you don't do it now). In addition, all intake upper and lower boots were replaced, secondary vacuum hose line rubber connectors were also replaced. Car idles perfectly now. Work was professionally done.

[triniguy99]

@trinjaminternational : I have a '99 323i with the same popping noise. It occurs only on a cold startup and the engine idles very rough. If put into drive it will sputter and misfire. However once the engine warms up and I power the engine off, wait 5 seconds and then restart, I can drive normal without any sputtering! Does this problem sound like what you have (with the Oil Separator valve)? Thanks..

[trinjaminternational]

@triniguy99 I was able to drive normally without the sputter, it became worse over time when it would eventually stall whenever I came to a stop. The idle would hunt erratically at idle also.

[triniguy99]

@trinjaminternational Ok thanks for the reply. Did the popping sound disappear when you changed the Oil Separator valve?

[trinjaminternational]

@triniguy99 Yup, instantly.

[triniguy99]

@trinjaminternational

I'm going to order the Oil Sep Valve and connector hoses, but there's one last thing I need to ask: I notice that it starts up very rough (erratic RPM..like in your case) and if I leave it to heat up for a couple minutes, then switch off the engine and after waiting a few seconds switch in back on, the car works like nothing was ever wrong- smooth idle, smooth acceleration. Was this your experience as well?

[triniguy99]

@trinjaminternational

There's one last question i need to bother you about: I noticed that if I start up (experience rough idle, erratic RPM like you did) and wait a few minutes for the temperature to reach the typical mid-level on the coolant gauge, then switch off the engine, then start it up again, the car works like nothing was ever wrong! Was this your experience as well? Thanks..

[triniguy99]

@trinjaminternational

There's one last question i need to bother you about: I noticed that if I start up (experience rough idle, erratic RPM like you did) and wait a few minutes for the temperature to reach the typical mid-level on the coolant gauge, then switch off the engine, then start it up again, the car works like nothing was ever wrong! Was this your experience as well? Thanks..