a lot of people on the facebook owners club mention a small puff on startup and say its not an issue if it goes away quickly.
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White puff of smoke at start only.. need your inputs !
- Thread starter AVCUPRA290
- Start date
Thanks mate,
I still have a puff at startup from time to time but not at each startup. Guess I will live with it.
My oil does smell like petrol though, will run a compression test in case of and the service is due for very soon so it might be dirty..
I still have a puff at startup from time to time but not at each startup. Guess I will live with it.
My oil does smell like petrol though, will run a compression test in case of and the service is due for very soon so it might be dirty..
I find it all depends on how long the car has sat for. If mine is overnight i do get a small puff. if its for a few hours i dont. I could say mine smells like petrol but it could also be burnt oil + fuel. Im going to do an oil change in the next few hundred miles and will be switching from 5w30 to 5w40. No idea if this will make a difference (likely not) but its unofficially adivised on higher mileage cupras.
Thanks for the feedback mate. Although this « issue » seems very common I cannot find any real answer to it.
Yes it depends on the time it sits : mine can do a puff after at least 20-30minutes off. Before it won’t. It seems it’s worse if the car is not parked on a plane surface.
also do you experience high suction at the oil cap when idling like I do ? I know I’m supposed to have some but this much I doubt it: Video
My actuhypothesis are :
- valve stem seals getting tired
- piston ring failure (thus oil smells like gas but I think smokes will happen when driving also)
- bad turbo seals (I think it would rather happen when exhaust is hot not immediately after start up and I might have a bigger oil consumption)
- injector messing up or bad coils but I think I would have error codes
odd that you mention parked on a plane as my car is parked on a slight downward slope. I often wonder if this has any affect at all...... I have light / medium suction on the oil cap ( i can easily remove it) at idle and the car stutters slightly if i remove it or the dipstick. I take this to be normal behaviour. I doubt it is rings in my case as the smoke is only on startup. Same for turbo seals.
My oil usage is also low so must only be small amounts of oil burning on startup. I would be very surprised if at 63k miles the oil stems are going bad especially as the car has had good servicing history from new.
I had noticed idle is very slightly lumpy on startup but i think this is also an EA888 trait and nothing to worry about unless its very noticeable in which case cam magnets are a likely culprit.
I will monitor mine and see if after a few hundred miles it is still there. i will also check after the oil change.
My oil usage is also low so must only be small amounts of oil burning on startup. I would be very surprised if at 63k miles the oil stems are going bad especially as the car has had good servicing history from new.
I had noticed idle is very slightly lumpy on startup but i think this is also an EA888 trait and nothing to worry about unless its very noticeable in which case cam magnets are a likely culprit.
I will monitor mine and see if after a few hundred miles it is still there. i will also check after the oil change.
Once again I’m not 100% sure and I also have smoke when parking on a plane so..odd that you mention parked on a plane as my car is parked on a slight downward slope. I often wonder if this has any affect at all...... I have light / medium suction on the oil cap ( i can easily remove it) at idle and the car stutters slightly if i remove it or the dipstick. I take this to be normal behaviour. I doubt it is rings in my case as the smoke is only on startup. Same for turbo seals.
My oil usage is also low so must only be small amounts of oil burning on startup. I would be very surprised if at 63k miles the oil stems are going bad especially as the car has had good servicing history from new.
I had noticed idle is very slightly lumpy on startup but i think this is also an EA888 trait and nothing to worry about unless its very noticeable in which case cam magnets are a likely culprit.
I will monitor mine and see if after a few hundred miles it is still there. i will also check after the oil change.
Yes it is normal as you are creating an air leak, the engine is designed to have a slightly negative pressure in order to pump those vapors back into the admission via the PCV and to allow better efficiency but I believe it’s around 100mbar below atmospheric pressure so as you mentioned : slight vacuum.
Mine as you can see is hudge and I wonder where it can come from, when engine one I can hear the PCV sucking air/oil.
Does an air leak somewhere else can cause this ? Like manifold seal leak ?
Same for me good service history in the same dealer it has been purchased new, and low mileage for valve stem seals but who knows..
My idle is perfect though..
I will try to consult some specialists in the coming week to see if someone can find something wrong with the car I don’t have the knowledge to dig deeper..
Just checked my new cupra 20 plate. 50k miles. sat for 24 hours. Stood behid it as my misses started it. ZERO smoke, not even a puff of smoke. This is after hammering it last night. I really was expecting something... but yeah nothing.
I will keep checking.
I will keep checking.
Hello,
After few startups in different conditions it seems that the white and slightly blue smoke (it is definitely oil) will only occur when starting in a not cold start => meaning that the oil/engine is not completely cold. After a night sitting, and with the morning cold start I do not have any smoke.
This could mean the valve stem seals are used and can let some oil pass into chambers when oil is thinner (not totally cold) when I start the car.
Some questions for you :
1) does it means oil is not dripping into chambers if not starting the car when oil is hot ?
2) do I have to replace the seals as soon as I can or do I wait till this go worse and use thicker oil ?
After few startups in different conditions it seems that the white and slightly blue smoke (it is definitely oil) will only occur when starting in a not cold start => meaning that the oil/engine is not completely cold. After a night sitting, and with the morning cold start I do not have any smoke.
This could mean the valve stem seals are used and can let some oil pass into chambers when oil is thinner (not totally cold) when I start the car.
Some questions for you :
1) does it means oil is not dripping into chambers if not starting the car when oil is hot ?
2) do I have to replace the seals as soon as I can or do I wait till this go worse and use thicker oil ?
To see if this is happening you can remove the coil pack and look down the spark plug well. See if you can see any oil another the spark plugs. You could also remove any that look suspect. That will be where the oil is leaking in. Also of people have this issue, they just deal with it and i believe that is VW's attitude on the matter. If its not causing misfires etc and only a little bit of oil it wont get done under any kind of warranty.
Yes I did check spark plugs when I noticed the first smokes but they were clean.
I will try to do it again soon while engine still warm.
This is still a sign of some seals wear.. and it will probably go worse in time no ?
And it can lead to carbon building inside the cylinder right ?
But yes for now it is only a bit of oil and plugs are not fooled at all..
So your saying it doesnt smoke atall on cold start or after being sat, its once its warm you get a bit of smoke?
No no smoke when the car is totally cold at least less likely since I started really monitoring it :
- if I restart the car immediately after stopping : no smoke
- smoke happens when parking for 30min to 4h (will monitor for 5-6-7-8h to see when I don’t have any)
- once, while parked on a slope I did have smoke after 45min parked and then shut off the car and tried again 3min later and got smoke again
If you are able to de-pressurise the high pressure fuel rail, soon after switch9sing the engine off, that check if that stopped the puff of smoke, that would definitely allow you to dismiss any injector weeping fuel into a cylinder while the engine was not running.
I was suggesting that, only to completely dismiss duff/leaking injector(s).
Maybe back 1988 I bought a new Ford Orion Ghia Injection, ie an XR3 with a boot and a stiffer body shell. It worked well, but, it could not be started "as per the owner's handbook" easily/quickly when warm or up to 8>10 hours after it had previously been used. Okay as it was a cable operated throttle, it would always start easily if the throttle was opened slightly, so I pressed the Ford dealership to make it work as per the owner's handbook, as my previous one, a 1984 version worked perfectly. They and Ford would not at first work out why I could not live with this issue, but I pointed out it was their published owner's handbook that "fixed" the "how to start the engine", so 2 visits later involving a complete rebuild of the metering head (Bosch K Jetronic) did next to nothing, so I bought a new single injector, checked its performance ie leakage and spray pattern at work using Freon and N2, then swopped it for the injector in the cylinder that "smelt of petrol" after a few hours - problem solved. Why Ford could not be bothered finding out the root cause when I even told them that if I released the fuel system pressure, there was never an issue and that the issue seemed to be with cylinder 2, I'll never know, but the less that they did, the harder I pushed - that was my last Ford that I ever purchased, for that and other reasons.
Anyway, there will be a few points where you can easily, if you have the technical ability, to safely crack the high pressure fuel rail supply to drop down its pressure.
Obviously, removing all the spark plugs after maybe 2 hours, and sniffing them, will give you an idea which if any of the injectors are weeping.
Maybe back 1988 I bought a new Ford Orion Ghia Injection, ie an XR3 with a boot and a stiffer body shell. It worked well, but, it could not be started "as per the owner's handbook" easily/quickly when warm or up to 8>10 hours after it had previously been used. Okay as it was a cable operated throttle, it would always start easily if the throttle was opened slightly, so I pressed the Ford dealership to make it work as per the owner's handbook, as my previous one, a 1984 version worked perfectly. They and Ford would not at first work out why I could not live with this issue, but I pointed out it was their published owner's handbook that "fixed" the "how to start the engine", so 2 visits later involving a complete rebuild of the metering head (Bosch K Jetronic) did next to nothing, so I bought a new single injector, checked its performance ie leakage and spray pattern at work using Freon and N2, then swopped it for the injector in the cylinder that "smelt of petrol" after a few hours - problem solved. Why Ford could not be bothered finding out the root cause when I even told them that if I released the fuel system pressure, there was never an issue and that the issue seemed to be with cylinder 2, I'll never know, but the less that they did, the harder I pushed - that was my last Ford that I ever purchased, for that and other reasons.
Anyway, there will be a few points where you can easily, if you have the technical ability, to safely crack the high pressure fuel rail supply to drop down its pressure.
Obviously, removing all the spark plugs after maybe 2 hours, and sniffing them, will give you an idea which if any of the injectors are weeping.
Thanks for the tip, I will look into it when I have the time. I also planned tomorrow to go into cylinders with an endoscope cam maybe an hour after turning off the car so if an injector is leaking I might see fuel dripping from it, and if it’s a valve seal issue maybe I will see oil dripping from the seats..
If its petrol leaking through the injector you will definitely smell it after 2 hours from the engine being fully warmed up.
I was wondering last time I check because I had one spark plug greasy of petrol the well was smelling petrol hard too compared to the 3 others.. but I thought it might be related to the position in which the engine stopped.
I will start with this well to make sure it doesn’t smell again
I will start with this well to make sure it doesn’t smell again
I worked on the theory that if one cylinder was ready to fire when the engine had been switched off, by the time 2 hours had passed, that petrol would have evaporated quickly so you would not really notice it, on the other hand, if that injector was weeping petrol into that cylinder, then it would continue to do that and as the engine cooled down, the fuel would not get evaporated so quickly - so you would be able to smell it in that cylinder a lot more than in any other "not weeping injector" cylinder.
Yes it makes sense, however in a leaky injector scenario I would also have smoke after a night sitting since the injector would still be weeping while engine cold. Except if somehow the engine being cold could also influence this leak..
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