Catalytic Converter puffing when engine off? 540i

[Tiger]

Wierd thing is happening... First the car is smoking alot... now engine is harder to crank which almost sounds like bad battery... and now the exhaust is puffing when engine is off.

LOL... it is funny... We came home from shopping... parked the car because I know I can't get the car started on it's own withiout a jumpstart battery pack. Even with the booster... engine still crank over slowly.

The point is car is parked... and we were waiting in other car and saw the exhaust puffing occasionally. A good plume of white smoke come out once a while... reminds me of Puff the Magic Dragon...

So what do you think? Think I got a leaky injector or maybe a bad coil that inject rich fuel mixture to my cats thereby plugging it up... causing resistance that the engine have hard time starting?

No check engine light at all.

[Jon K]

white smoke = coolant = headgasket.

sticking injector will be like a hickup, car should still run, i doubt you'd see it but a too rich condition would be black smoke but you've got a cat so it'd be real faint.

oil burns blue and probably wouldn't burn bad enough to REALLY tell at idle unless your rings/valve seals are really forked.

[Bill R.]

determine which one is wet like a stuck open injector filling up a cylinder... and if the cat is hot and some of the fuel vapors are getting to it then you'll see the puffs that your talking about but the cat is going to be blazing hot also. And its not that the cat gets plugged up, its that it melts down and fuses together causing a plug or blocked passages.



Wierd thing is happening... First the car is smoking alot... now engine is harder to crank which almost sounds like bad battery... and now the exhaust is puffing when engine is off.

LOL... it is funny... We came home from shopping... parked the car because I know I can't get the car started on it's own withiout a jumpstart battery pack. Even with the booster... engine still crank over slowly.

The point is car is parked... and we were waiting in other car and saw the exhaust puffing occasionally. A good plume of white smoke come out once a while... reminds me of Puff the Magic Dragon...

So what do you think? Think I got a leaky injector or maybe a bad coil that inject rich fuel mixture to my cats thereby plugging it up... causing resistance that the engine have hard time starting?

No check engine light at all.