white smoke need help!

[Danishp97]

https://youtube.com/shorts/cZ_nSMZbE...Mct7IEMgDisLjv


Hi everyone! I have catless downpipes and stage 2
Recently i noticed this at a traffic light when someone with bright white lights was behind me. The smoke is super faint and is only noticeable under white light. Car is usually driven 25/30 miles a week. Is this normal smoke? It’s very humid where i live

[M5Rick]

If it's white smoke then means coolant could be entering the combustion chambers and a head gasket may be slightly leaking, it's faint coming out the right side bank pipes and doesn't appear to be that bad. If the smoke gets worse then may mean a head gasket replacement on that side.

[Danishp97]

Originally Posted by M5Rick

If it's white smoke then means coolant could be entering the combustion chambers and a head gasket may be slightly leaking, it's faint coming out the right side bank pipes and doesn't appear to be that bad. If the smoke gets worse then may mean a head gasket replacement on that side.

Got it! The smoke is there on both sides. Just that its so faint that only capture when light is pondered upon it upclose

[M5_Raz]

It’s normal, mine’s the same.

[jnotrom711]

Originally Posted by M5Rick

If it's white smoke then means coolant could be entering the combustion chambers and a head gasket may be slightly leaking, it's faint coming out the right side bank pipes and doesn't appear to be that bad. If the smoke gets worse then may mean a head gasket replacement on that side.

Most of this is true as to what it could be, however, f10 and newer 4.4L V8 M5, M6,M8 X5, X6, including F90 M5 + use cross bank turbo manifolds. So 2 cylinders from each (L & R) cylinder bank feed each turbo. So no real way of knowing which side a head gasket could be needed on based solely on exhaust smoke or lack there of....unless OP modified his exhaust and turbo manifolds to manifolds like the 550i... I would doubt that, but anything is possible I suppose. Not even sure you can modify the manifolds in that manner, or if modifications exist for this. That would also make it sound more like a traditional V8, like the 550i, or AMG cars etc.

OP mentioned smoke on both sides anyway so its either mixing inside the exhaust, or just no real way to know which side with out further diagnosis.

[Blaxwil]

That appears to be normal exhaust gases.

[M5Rick]

Maybe you used a different petrol this time to make it do that Danishp97.
Looking at it again I don't think there's a problem.

[Danishp97]

Originally Posted by M5Rick

Maybe you used a different petrol this time to make it do that Danishp97.
Looking at it again I don't think there's a problem.

In my country ethanol blending has increased over the past few months. Also the fuel was almost 25 days old

[M5Rick]

Originally Posted by Danishp97

In my country ethanol blending has increased over the past few months. Also the fuel was almost 25 days old

I don't suppose you have Texaco 99 Supreme Performance there, I use it and contains very little or no ethanol, perfect for M5.

[Danishp97]

Originally Posted by M5Rick

I don't suppose you have Texaco 99 Supreme Performance there, I use it and contains very little or no ethanol, perfect for M5.

No I don’t. India has very bad fuel anyway

[M5Rick]

Originally Posted by Danishp97

No I don’t. India has very bad fuel anyway

In a country bordering Germany I was told that it was suspected that lesser known fuel companies there were adding water to the forecourt fuel tanks which would cause some white smoke and stuttered running.