Mintyfresh77
Member
Chaps,
Before I start it's best to get the obvious ones out of the way first when mentioning cold start issues. The car had 4 new OE glow plugs and Glow plug relay fitted early this year to resolve very bad cold starts and it has run beautifully since but slowly over the last few weeks I've been noticing a rough initial startup almost like not all cylinders are coming to the party and once started it idles but with a gentle surging that actually rocks the car. Once the engine is up to temperature it's no where near as noticeable but I can still feel it when sat at lights or at junctions. On the go it performs perfectly fine, smooth power delivery, no smoke, no hesitation. I cleaned PCV pipework and turbo intake yesterday with brake cleaner and rag but was only very slight oil residue anyway I also blasted the MAF with brake cleaner. I removed the EGR today and was surprised at how little cleaning was required on a 122k engine. I did a leak off test last week on a warm engine as the wife forgot I needed it cold and nothing untoward on leak off quantities but wonder if it would be a different story on a cold start leak off?...I tried unplugging the MAF while it was idling earlier and it seemed a little smoother but engine was warm (again perhaps something that needs to be done on 1st crank of the day). Rail pressure according to my icarsoft is a constant 235bar at idle but honestly I'm not sure if that's normal or horrifically low? I can see lots of data but i'm not ashamed to admit I don't know what I'm looking at in all honesty. Any ideas guys?
Not sure if it's worthy of mention ad it's always done this in the 6 months I've owned the car but when turning ignition on before crank there is a curious noise from the fuel lines area like a pressurising noise that creates a whirring or muted whistling noise. I figure it's the fuel system pressurising and perhaps purging any air in the lines but that is purely a guess. It lasts for about 20-30 seconds which seems overly long for a pre startup procedure.
See youtube link Strange Noise - OM646 pre startupto video.
Before I start it's best to get the obvious ones out of the way first when mentioning cold start issues. The car had 4 new OE glow plugs and Glow plug relay fitted early this year to resolve very bad cold starts and it has run beautifully since but slowly over the last few weeks I've been noticing a rough initial startup almost like not all cylinders are coming to the party and once started it idles but with a gentle surging that actually rocks the car. Once the engine is up to temperature it's no where near as noticeable but I can still feel it when sat at lights or at junctions. On the go it performs perfectly fine, smooth power delivery, no smoke, no hesitation. I cleaned PCV pipework and turbo intake yesterday with brake cleaner and rag but was only very slight oil residue anyway I also blasted the MAF with brake cleaner. I removed the EGR today and was surprised at how little cleaning was required on a 122k engine. I did a leak off test last week on a warm engine as the wife forgot I needed it cold and nothing untoward on leak off quantities but wonder if it would be a different story on a cold start leak off?...I tried unplugging the MAF while it was idling earlier and it seemed a little smoother but engine was warm (again perhaps something that needs to be done on 1st crank of the day). Rail pressure according to my icarsoft is a constant 235bar at idle but honestly I'm not sure if that's normal or horrifically low? I can see lots of data but i'm not ashamed to admit I don't know what I'm looking at in all honesty. Any ideas guys?
Not sure if it's worthy of mention ad it's always done this in the 6 months I've owned the car but when turning ignition on before crank there is a curious noise from the fuel lines area like a pressurising noise that creates a whirring or muted whistling noise. I figure it's the fuel system pressurising and perhaps purging any air in the lines but that is purely a guess. It lasts for about 20-30 seconds which seems overly long for a pre startup procedure.
See youtube link Strange Noise - OM646 pre startupto video.