[Jet1990]

Hi all I've owned my 330i for around 3 weeks now n I've noticed that the car seems to give off quite abit of white smoke even when the engine is upto temp.

First thing in the morning there's no smoke and after 5 mins it's smoking like how cars do in in a morning. This also happens regardless of the time of day. I have a fault code saying g the nitric oxide cat is ageing so I'm wondering if that could be the issue. I've also read that it could be the head gasket gone. Engine is on 70k. The recent service shows that they swapped the exhaust cam shaft sensor swapped with inlet manifold. Does this mean anything to anyone?

[alex-qts]

Originally Posted by Jet1990

Hi all I've owned my 330i for around 3 weeks now n I've noticed that the car seems to give off quite abit of white smoke even when the engine is upto temp.

First thing in the morning there's no smoke and after 5 mins it's smoking like how cars do in in a morning. This also happens regardless of the time of day. I have a fault code saying g the nitric oxide cat is ageing so I'm wondering if that could be the issue. I've also read that it could be the head gasket gone. Engine is on 70k. The recent service shows that they swapped the exhaust cam shaft sensor swapped with inlet manifold. Does this mean anything to anyone?

Not much help but both my E46 330i and my E92 335i chucks out quite a bit of white smoke in the winter months (more than most cars do) might be to do with it being a bigger engine, taking longer to warm up? Anything remotely close to cold weather and it smokes. Have also spotted lots of 3.0l+ BMW's doing the same around here, even the new M3/4's.

I would be interested to know some more info around this too...

[Soul_Glo]

Makes no sense to swap two sensors with one another as part of a service. Did they replace either/both? Or just do it to cross diagnose and found nothing?

Coolant level okay? No mayo under the oil cap?

Car hasn't done a few short runs has it? Sometimes when the cats are not fully up to temperature and especially in cold weather there can be excess moisture in the exhaust system to burn off. So after 5 minutes you are getting warmer and warmer. Our cars run rich in the cold. If after an hour of driving you still have excess white smoke on idle.. Having ruled out coolant leaks... Coolant mixing with oil... You can probably assume that it is the valve cover gasket... Or could be something else related to the exhaust system.

[Ao1]

Originally Posted by Jet1990

Hi all I've owned my 330i for around 3 weeks now n I've noticed that the car seems to give off quite abit of white smoke even when the engine is upto temp.

First thing in the morning there's no smoke and after 5 mins it's smoking like how cars do in in a morning. This also happens regardless of the time of day. I have a fault code saying g the nitric oxide cat is ageing so I'm wondering if that could be the issue. I've also read that it could be the head gasket gone. Engine is on 70k. The recent service shows that they swapped the exhaust cam shaft sensor swapped with inlet manifold. Does this mean anything to anyone?

I had a similar issue. It was a sensor malfunction resulting in excessive fuel being used, hence white smoke. It was evident on tick over and really evident on hard acceleration.

[AndyT330i]

Originally Posted by Ao1

I had a similar issue. It was a sensor malfunction resulting in excessive fuel being used, hence white smoke. It was evident on tick over and really evident on hard acceleration.

Just out of interest which sensor was it?

[Ao1]

Originally Posted by AndyT330i

Just out of interest which sensor was it?

It was fixed under warranty but if I recall correctly it was the oxygen sensor.

[AndyT330i]

Originally Posted by Ao1

It was fixed under warranty but if I recall correctly it was the oxygen sensor.

Cheers

[Jet1990]

Originally Posted by Broken_Gearbox

Makes no sense to swap two sensors with one another as part of a service. Did they replace either/both? Or just do it to cross diagnose and found nothing?

Coolant level okay? No mayo under the oil cap?

Car hasn't done a few short runs has it? Sometimes when the cats are not fully up to temperature and especially in cold weather there can be excess moisture in the exhaust system to burn off. So after 5 minutes you are getting warmer and warmer. Our cars run rich in the cold. If after an hour of driving you still have excess white smoke on idle.. Having ruled out coolant leaks... Coolant mixing with oil... You can probably assume that it is the valve cover gasket... Or could be something else related to the exhaust system.

Coolant level is fine. No gunk in oil cap. There's a error code saying the nitrogen oxide cat s ageing so I'm torn between thinking the cat is agei ng and it's giving the white smoke or the nox sensor is faulty and causing the car to run rich. First thing in in a morning it doesn't smoke until about 5 mins have passed.

[Soul_Glo]

Originally Posted by Jet1990

Coolant level is fine. No gunk in oil cap. There's a error code saying the nitrogen oxide cat s ageing so I'm torn between thinking the cat is agei ng and it's giving the white smoke or the nox sensor is faulty and causing the car to run rich. First thing in in a morning it doesn't smoke until about 5 mins have passed.

Sounds plausible.