Peterdarcy
New member
Can anyone explain why approx 1 in 20 times I cold start my boxster I get blue smoke, nothing on subsequent starts or when running, no excessive oil use, no sign of smoke when driven hard? Any ideas appreciated!
Smokey exhaust on start up?
- Thread starter Peterdarcy
- Start date
Probably nothing to worry about Peter. Blue smoke from the exhaust generally means that the engine is burning oil but with the flat-6 boxer layout, oil can collect in the bores if the car has been standing which burns off when the car is started.
If, as you say, you're not getting high oil consumption in normal use and aren't trailing excessive smoke there's no cause for alarm. Of course, depending upon the mileage of your car there will always be some wear in the engine components eg cylinder bores, valve guides and seals, etc.
Jeff
Peterdarcy
New member
Many thanks for the advice all
Probably nothing to worry about Peter some do it some dont.
The horizontally opposed Boxer engine in the Boxster has the bores very low down, oil is pumped up to the valve gear and upper extremities, this oil drops back down into the sump, when hot the oil is thin and runs easily, when you switch off oil continues to drain down.
Some spots of oil splash into the bore behind the pistons and being quite thin it travels towards the piston and gathers there, If the car is parked on an incline (left to right - not front to rear) there is a greater chance of these oil splashes dripping into the bores - and the incline will assist the oil travel behind the piston.
When metal is heated it expands and when cooled it shrinks, as the engine cools the pistons return to their slightly oval shape (Yes they are Oval although to the naked eye they look round - this ovalness is designed this way to allow for the expansion - there is more metal at the little end joints than on the piston skirt so there will be more expansion and a greater tollerance is required at these two points otherwise the engine would sieze)
As the pistons return to their cool state and the greater tollerance is present oil eventually finds its way by the oil scavenge ring and the piston rings and makes it way into the combustion chamber, hence when you start up you get the puff of smoke.
Just a tiny amount of oil makes a lot of smoke.
The greater the mileage the greater the wear in the bores, pistons and piston rings, so a greater chance of producing smoke - or should i say more smoke.
Oil burning is perfectly normal for Boxer engines, I know its a bit embarrasing to have such a premium marque car that smokes - and it encourages your workmates to have a little chuckle at it, but its a fact of the engine design.
You will also note there are many posts on this subject and people say "white smoke and Blue smoke" truth is smoke is oil burning - which has a blue tinge and white is steam - the steam is condensed water heated by the catalyst and vaporised, but people say white smoke as if thats oil burning but in a different way - said by many so they get a reply that is less serious - a little like having an xray touched up, they would be happier.
Try parking on level ground or park the car the other way around, you may find this stops the smoke, The car after a good few years will dip slightly on the drivers side as that is usually where the additional weight is and springs like everything else gets tired over time, so that could assist oil splashes into the bores
Some spots of oil splash into the bore behind the pistons and being quite thin it travels towards the piston and gathers there, If the car is parked on an incline (left to right - not front to rear) there is a greater chance of these oil splashes dripping into the bores - and the incline will assist the oil travel behind the piston.
When metal is heated it expands and when cooled it shrinks, as the engine cools the pistons return to their slightly oval shape (Yes they are Oval although to the naked eye they look round - this ovalness is designed this way to allow for the expansion - there is more metal at the little end joints than on the piston skirt so there will be more expansion and a greater tollerance is required at these two points otherwise the engine would sieze)
As the pistons return to their cool state and the greater tollerance is present oil eventually finds its way by the oil scavenge ring and the piston rings and makes it way into the combustion chamber, hence when you start up you get the puff of smoke.
Just a tiny amount of oil makes a lot of smoke.
The greater the mileage the greater the wear in the bores, pistons and piston rings, so a greater chance of producing smoke - or should i say more smoke.
Oil burning is perfectly normal for Boxer engines, I know its a bit embarrasing to have such a premium marque car that smokes - and it encourages your workmates to have a little chuckle at it, but its a fact of the engine design.
You will also note there are many posts on this subject and people say "white smoke and Blue smoke" truth is smoke is oil burning - which has a blue tinge and white is steam - the steam is condensed water heated by the catalyst and vaporised, but people say white smoke as if thats oil burning but in a different way - said by many so they get a reply that is less serious - a little like having an xray touched up, they would be happier.
Try parking on level ground or park the car the other way around, you may find this stops the smoke, The car after a good few years will dip slightly on the drivers side as that is usually where the additional weight is and springs like everything else gets tired over time, so that could assist oil splashes into the bores
Peterdarcy
New member
Thanks for taking the time to give such detailed explanations
, I feel at ease now, appreciate the help all!
, I feel at ease now, appreciate the help all!
Posts made and opinions expressed are those of the individual forum members
Use of the Forum is subject to the Terms and Conditions
