Help Need with E92 white Smoking very Bad from Tail Pipe and engine

[M3ryder55]

Its my brothers car

2012 M3 16K miles Was on the freeway going 40 MPH car is all warmed up he gunned it shifted into third gear everything is normal but a cloud of white smoke started coming from the exhaust

We pull over and the car idle's fine drives fine no knocking sound from the engine just a lot of white smoke coming out of the tail pipe and engine compartment .

Has this happened to anyone else, could it be a bad spark plug or a rod bearing?

[335m]

Check for leaky seals & gaskets, and check all fluid levels first.

DO NOT DRIVE until you figure out if you are leaking oil/coolant and a compression check is done.

[BzsBimmer]

Smoke of this sort is usually caused by the engine burning coolant, and can be the result of a blown head gasket or a damaged cylinder head, or a cracked engine block, which requires a new engine or an engine rebuild.

[vsix]

White smoke during woot = no good.
Cracked cyl. head/ block/torn gasket, therefor coolant fluid gets burned and causes white smoke.

[IIAp3x]

Are you sure it's coming from the exhaust? A slipping, burning clutch disc also emits a white smoke with a very distinct and unpleasant smell...

[M3ryder55]

White is coming out on idle or when gas is applied. smells like oil/gas not sweet

[BzsBimmer]

Are you sure it's not condensation

[Killerfish2012]

Originally Posted by M3ryder55

Its my brothers car

2012 M3 16K miles Was on the freeway going 40 MPH car is all warmed up he gunned it shifted into third gear everything is normal but a cloud of white smoke started coming from the exhaust

We pull over and the car idle's fine drives fine no knocking sound from the engine just a lot of white smoke coming out of the tail pipe and engine compartment .

Has this happened to anyone else, could it be a bad spark plug or a rod bearing?

My guess based on a similar situation, is thermostat housing gaskets. Take it to a dealer.

[Umi|all|day]

Originally Posted by M3ryder55

Its my brothers car

2012 M3 16K miles Was on the freeway going 40 MPH car is all warmed up he gunned it shifted into third gear everything is normal but a cloud of white smoke started coming from the exhaust

We pull over and the car idle's fine drives fine no knocking sound from the engine just a lot of white smoke coming out of the tail pipe and engine compartment .

Has this happened to anyone else, could it be a bad spark plug or a rod bearing?

Happened to me! I think you T-Mat or water pump went out. Either of those two. Get it checked. Do not drive it. Because I did and the engine just overheats.

[M3ryder55]

Originally Posted by Killerfish2012

My guess based on a similar situation, is thermostat housing gaskets. Take it to a dealer.

and you where smoking bad from the tail pipe but the car idle fine and drove fine

[Killerfish2012]

Originally Posted by M3ryder55

and you where smoking bad from the tail pipe but the car idle fine and drove fine

Smoking from the tailpipe, and front of the hood. You could also smell coolant, after a couple of days. Get it checked out.

[pbonsalb]

I agree with the recommendations to check for a coolant leak. Rule out the external leak first. It can drip down onto exhaust and blow out the back. Internal leak means cracked head or block or blown gasket and the white smoke would come only out the exhaust. I also agree with smelling the white smoke since oil and coolant smell very different.

My guess is a coolant leak under the hood from the description.