[330ci]

My e90 320i with an N46 engine has been smoking recently. White smoke comes from exhaust slowly and continuously. Also doesn't look like thick white smoke, has some opacity to it if that makes sense. And no tinge of blue in the smoke.

No coolant loss, never overheated. Car has 160,000km (approx 100,000miles)

I can't tell what it smells like but smells kind of toxic. It doesn't smell like oil like from a typical valve stem seal. Doesn't smell like antifreeze coolant burning (don't know how this actually smells but apparently it's sweet and this doesn't smell sweet). The smoke sets off all the smoke alarms whenever I run the engine for about 5 minutes.

Issues:

1. I have a few oil leaks on VCG.
2. Vacuum pump is also leaking oil and that was replaced with non-genuine part by a local shop (not sure what brand but not cheap ebay quality).
3. Oil sump is also leaking (drips oil onto ground).
4. OFHG was leaking but that has been replaced.
5. VANOS Solenoid Valve Seals are leaking.
6. Camshaft plate cover at rear of engine slowly leaking coolant
7. Done around 110,000km (or ~70,000 miles) on spark plugs
8. Loud whistling/whining noise when I fill up petrol into tank. Almost like the air that's being displaced by the petrol has nowhere to escape

I pulled the spark plugs - all electrodes and tips look white with slight bit of orange that looks like something is burnt. Not sure if it'll help, but I've attached some photos of spark plugs.

Most people online say small head gasket leak but I think it's something else entirely. Assuming the spark plugs look abnormal, I doubt that all cylinders would be leaking coolant to cause them to all wear the same. Also the spark plugs seem like they are all worn the same which makes me think it's happening across all My initial thoughts were that it could be a possible fueling issue, bad injectors, bad AFR from all the vacuum leaks.

Hope someone has some insight into how I should go about diagnosing this issue and what possible causes. If anyone else has had this and fixed it successfully, please chime in.

[NZE90]

Looking at your plugs, your engine is burning oil which is probably your smoke issue. The most common cause on an N46 engine is either a blocked CCV valve/hoses or worse case is valve stem seals. The valve stem seals are a major job. Does your car have the CCV on the valve cover or under the intake manifold?

[330ci]

Originally Posted by NZE90

Looking at your plugs, your engine is burning oil which is probably your smoke issue. The most common cause on an N46 engine is either a blocked CCV valve/hoses or worse case is valve stem seals. The valve stem seals are a major job. Does your car have the CCV on the valve cover or under the intake manifold?

After more research, I also think its oil burning. My CCV is on the valve cover (PN: 11128645888), not under the IM.

As I am new to this car and bought it from auction, I found the old owner's contact details and he said the car blew white smoke when idling at a stop, and when taking off it would blow a bit more (but not big cloud like).

There's a similar thread here (link) where the guy had white smoke from exhaust and replaced valve stem seals but continued to have white smoke and oil consumption. Sounds quite like my issue which leads me to think it's CCV or piston rings.

It doesn't seem to have the traditional oil cap suction to indicate bad CCV. Regardless, I am going to try use an aftermarket repair kit to replace only the CCV (can't justify replacing whole valve cover just for this).

I'll report back once I've replaced CCV.

[NZE90]

Make sure the CCV breather passages in the valve cover aren't blocked if you'regoing to repair it. I would be inclined to replace the whole valve cover. They have a bad habit of warping and cracking being plastic. Worn piston rings aren't really common for your engine, it's more likely to be valve stem seals. I've replaced a lot of valve stem seals on the N46 and it always fixed the problem.

[330ci]

Originally Posted by NZE90

Make sure the CCV breather passages in the valve cover aren't blocked if you'regoing to repair it. I would be inclined to replace the whole valve cover. They have a bad habit of warping and cracking being plastic. Worn piston rings aren't really common for your engine, it's more likely to be valve stem seals. I've replaced a lot of valve stem seals on the N46 and it always fixed the problem.

I might consider replacing the VC entirely but want to check whether CCV is the culprit of smoke first. The prev owner needed to replace the VCG 3 times in the space of 70,000km which seems excessive. Maybe it leaked from not putting RTV on the half moons. Or maybe it didnt last coz of excess crankcase pressure.

As for the hoses, I think there's only one CCV hose on the N46 that goes from IM to VC. I'll consider replacing it after I fit CCV repair kit.