Early Morning Roar

[xfactor78]

Hi guys,

New to this forum, just need to check with the experts if anyone came across their E46 giving a roaring sound in the morning upon starting the ignition?

 

[rex7_vtec]

Hi xfactor78, welcome to BMW.SG it would be nice if you could do an introduction in teh Newbies folder

As for the roaring sound you are experiencing, care to perhaps give us a more specific description? From engine, or exhaust?

 

[xfactor78]

The sound is likely from the engine.
But if i switch it off and restart, its fine though.

 

[Racebred]

could be mercedes engine hiding inside.

most probably is the fan.

 

[xfactor78]

Thanks for the reply.
Is it something I should be concerned with?

 

[Whisky_Tango]

Not sure on ur defination.

But every morning cold start, the engine rev will be higher than normal. This is controlled by the ECU so as to warm up the engine. Once the Cat and engine oil temp is to the ECU settings, the rev will drop.

Think it takes about 2mins or so for the rev to drop back to abt 800rpm.

Cheers!

 

[precurser]

Is it advisable to drive while the rpm is still hovering at about 1000 or wait till the revs drop to the designated idling speed?

 

[Whisky_Tango]

Is it advisable to drive while the rpm is still hovering at about 1000 or wait till the revs drop to the designated idling speed?

My take is no problem. But do not cross over 2000rpm within 5mins from cold start.

After 5mins, just gradually increase rev but not WOT.