radumalica

Hi guys,

I have a 2008 530i N52 engine (car is LCI) with 98000 km , all service done at dealership until 88000 km. Car ran fine, until 2 weeks ago when i revved it in gear up to 4000 rpm and a big cloud of white/grey smoke came out the exhaust,(not sure about the actual color as i was driving about 100km/h) and the engine started to misfire.

Stopped the engine, started again, working fine, no rattling, no erratic idle, no smoke.

Facts:
- when i rev it more than 3000 rpm the smoke comes out only one shot, no smoke after, and not always i get the misfire. This happens only when driving, not stationary.
- when the engine is cold the idle is rattling (rpms drop below normal, then go up to 1000 rpm, and so on) until you rev it a few times, or just drive it 1 km , then it is stable.

I wanted to say, being "cold" means that right now there are 26 degrees C outside in the morning, and 36C during day.

When i had the smoke and misfire , i scanned with INPA and i had the following codes:

2c2d - Precat 02 thrust control, Bank 1
2c3d - Precat 02 sensor lines/wires, Bank 1
29d0 - Misfire cylinder 4
29d1 - Misfire cylinder 5
29cc - Misfire, several cylinders


I just went before this event to BMW dealer for the brake pad replacement (as i have extended service contract) and the only things needed to be change but not critical where some front bushes and pan gasket + valve cover gasket, although the leaks are not consistent, there are barely some spots which are already dry.

Oil level is normal, green.

Any ideas, could the misfire be caused by malfunctioning O2 sensors at high revs ? What about the smoke, unless i floor it, i don't EVER get any smoke and the exhaust smells normally , no smoke smell or rich fuel smell.

Thanks

Andrew06

With codes all over the place like this, i would clear them and watch what (if anything) returns. Our cars are a lot more sophisticated than most, and they notice things that most engine management systems don't, so sometimes it is nothing.

I would change the oil and see what happens. Reason is, I think your problems are caused by VANOS solenoids, and sometimes an oil change is all they need to be happy again. Especially after service there can be debris in the oil that will irritate the VANOS system. My car ran horribly after doing the oil filter housing gasket, all kinds of VANOS and misfire codes. Oil change solved them all. Spark plugs are a painless preventative maintenance item too. Techron by Chevron wouldn't hurt either, but i think this will work itself out.

radumalica

Hi

Yesterday i checked the coolant, level was ok, i added about half a coffee cup and the dipstick was up to max. No signs of oil,

But, i read like 3 hours all over the forums about this, and found out that my engine has the CCV integrated into the valve cover. So, i started the engine, and when i opened the oil cap, voila, negative pressure, it was sucking air inside. So i guess it is time for a new valve cover and gasket....

Just wanted to confirm that all these symptoms can be caused by the clogged CCV . Anyway, i will change the plugs and all the filter plus oil as the consumables are due, and also change the valve cover and see what is happening.

radumalica

this is what i have filmed this morning: https://www.youtube.com/watch?v=lH5P...ature=youtu.be

rev at 0:20 is me, but until then you can see some not so stable idle. Before i started filming, the rev dropped down to almost 500rpm, then again up.

other times on the first start, it shakes a bit like something is misfiring but again, after driving half mile everything is swiss clock.

Should i change oil, valve cover and sparks, and check again the behavior ?


Thanks for the answers

Andrew06

Those are all good ideas. The CCV system is a known weakness in higher mileage cars, so fixing the leak and CCV would certainly be a positive. I guess i would do everything else first before the valve cover, as it's the most invasive. Maybe Oil, then plugs, then coils, then vanos solenoids. If it doesn't purr like a swiss watch at that point then do the valve cover and ccv. You should then be in pretty darn good shape.

Also fuel really does matter, if you haven't been running a top tier gas (google it) than do so. Chevron by techron is a good idea either way.

It's just good to be able to say that you checked all the minor things before you tear in too deep.

radumalica

Thanks

I've ordered the valve cover though, the gasket needs replacing, and i can' think of other possibility than the integrated CCV, as the diaphragm breaks the intake vacuum sucks the oil into the manifold causing smoke, but this only occurs at high rpm, probably when the vacuum is very high.

i don't see any problems with vanos solenoids as no errors are displayed about those. Causing the idle to be swiss watch when hot, sends me thinking that maybe i have problems with the plugs or some coils, but the smoke definitely is not from that.

Even in this situation, i have no EML light on the dashboard.

radumalica

Back again ,

I changed the valve cover, coils and plugs, still have some smoke at high revs and the O2 error plus misfires

I am trying now to change oil , precat o2 sensor and vanos solenoids to see

radumalica

Back with good news, i should have listened to Andrew06 in the first place.

I changed the oil and put Mobil1 0w40 and now i have no rough idle or smoke. still the O2 sensor needs to be changed, but this is a great improvement.