Mazda Mazda 6 (2002 - 2007) - 04 2.0 Smoke on start up

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Thu 7 May 2009 15:28
04 2.0 Smoke on start up - olly1
Recently bought an 2004 mazda 6 diesel estate with 50k miles on the clock. Been very pleased with it, but have noticed that it sometimes kicks out a large cloud of grey smoke on start up. This seems to normally happen when it has been parked facing down hill, and not only after a long rest; today it happened after the car had only been left for 2 hours - hardly long enough to cool down fully. At home I always park on my drive which faces up hill and it never happens there. I have seen this fault mentioned on forums before, but there has been no suggestion as to the cause. Being reasonably familiar with diesel engines this is the sort of smoke you get when there is excess fuel at start up i.e. it is effectively unburnt fuel, and this would be consistent with its smell. The car always starts very quickly so it is not due to diesel building up due to long cranking before starting. I assume therefore that fuel is getting into the cylinders while the engine is stopped with the car facing down hill and is kicking it out as the smoke when it is next started. Sounds like there is possibly a defective valve which is supposed to stop this type of gravity feed when the engine is stopped. Any idea where this might be or any other suggestions? Have people who have experienced the major fuel pump problem noticed this in the run up its failure?
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Thu 7 May 2009 23:33
04 2.0 Smoke on start up - dagenham car center
is it a conventional diesel or high pressure one?
get the engine systems diagnostic codes read first,if none stored then
get the glow plugs checked/or replaced.somtimes they work but dont get hot enough.
if after this it still does then get the injectors tested,they could be dribbleing diesel overnight into engine!

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Fri 8 May 2009 10:22
04 2.0 Smoke on start up - olly1
Thanks for the suggestions. Its a common rail diesel so high pressure. I am rather confused about the smoke only showing when the car has been parked facing down hill, hence my suggestion of a faulty valve of some sort. Can't see glow plugs working differently at different angles, but could perhaps go with dribbling injectors. I am not familar with how they work on these engines, but would have thought that such a fault would have other symptoms, but the car drives perfectly; plenty of power, only smokes with foot to the floor, no misfires. I think I will need to get the dealer to read any codes first as you suggest. Thanks
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Sat 20 Jun 2009 23:53
04 2.0 Smoke on start up - zoom1965
Hi olly1
Did you sort your problem with smoking on start up when facing downhill. My vehicle has just started to do the same . Has done 42000 miles and had a replacement pump at approx 22000 . Any info would be most welcome
zoom1965
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Sat 29 Aug 2009 11:56
04 2.0 Smoke on start up - zoom1965
For anybody that is interested,car developed heavy breathing and smoke coming out of the oil filler when running.Still ran ok,didn't use any oil so monitored for a month. Got recalled to Mazda for engine remap and intercooler check, so I asked them to check injector seals whilst with them.Found one of the injector seals to be leaking causing blow-by. Have only had car back a few days and seems to have cured fault.
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Fri 2 Sep 2011 20:16
04 2.0 Smoke on start up - Rosco3045

Hi sorry to bump an old thread but I have just bought a mazda 6 2.0 diesel estate 2006 model and I have this exact problem. When I park on a hill for an hour, I start up to drive off and my car is surrounded in a plume of smoke. As I drive off I leave a trail for a few seconds then all is clear. The car drives perfectly as you described so I suspect I may your exact fault. Did your new seals fix your issue and if so can you remember how much they were?

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Mon 12 Sep 2011 19:02
04 2.0 Smoke on start up - pieater
I have the exact same problem on a 6 ts2 does anyone have a resolution as it is really hard sometimes to find a hill to park on facing up...anyone?
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Sat 22 Aug 2015 14:26
04 2.0 Smoke on start up - Chrisndaz

Has anyone found the reason?

Three garages can't!

It's all about facing down hill and is such a shame cos its a lovely car

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