We drive two Volvos with the 2.4 petrol engine, one V50 (2010; 50,000km) and one S40 (2007; 124.000km); both machines, thus quite well comparable. The S40 has for some time a very rough, loud, roaring engine at the cold start. Comes from the engine compartment and sounds a bit as if the exhaust was leaking at the front. When driving off the car the noise is quite loud. Over the first 500m-1000m or so the engine noise becomes always quieter and then normal. The consumption is around the 7.1 L (is cruise route in Switzerland), it needs some oil (100 to 150ml/1000km), rarely it squats briefly when running on the highway. After warm starts the S40 behaves quite normal, hardly up to no tubes/crumbs… The question is now: what can this lie on? Let the worry and workshop check or drive up to the service (is at 130,000km, approx. mid-October)? Thanks, all on all sides good journey and bes te Greetings Peter p.s.: by the way, the engine noise has nothing to do with the higher turning idle when starting, that’s what our S40 and the V50 do over the first 30sec at the stand or until you put the automatic on R/D and start driving.