Cvv and repetitive clogging

[spyderg0d]

After driving the car a long period of time on the highway, it seemed the oil finally cleared out of the sensors for the most part. All the fuel trims went under 10 almost all together. New manifold gasket, new throttle body gasket. I siliconed every connection on the intake and made sure 100% no vacuum leaks anywhere.
I think with more driving, the fuel trims will get better.

[MarcoZandrini]

Actually condensate does form in the inside of the engine. The purpose of the CCV is to suck that crap out, route the fumes to intake and dump the rest into the oil pan.

[spyderg0d]

Obviously condensate forms in the engine.. How much and where is the problem...

[dworthy]

If there is/was an over fueling, that could have contaminated the oil. With the oil heating up, and the fuel turning to vapors, then going thru the CCV into the intake getting burned. It will take some time to get rid of the fuel, so I would say an hour or more of driving to get those STFT numbers down.

How does the LTFT look? What you want if under 10% for the LTFT, and 20% for the STFT as they will go up/down the most anyway.

[MarcoZandrini]

Darin, or 20 minutes on the autobahn!!!

[Critter7r]

We had a conversation about this here at the shop the other day. One of the guys was saying that gasoline mfrs now are putting additives into gas that holds water in suspension in the gas instead of allowing it to separate out from the gas. So it just gets sprayed into the combustion chamber a little at a time instead of all at once when you run low on gas. The upside is that you don't get a puddle of water in the bottom of your gas tank separated out from the gas. The downside, especially for BMW owners with these CCV systems, is that there's even more water vapor flowing thru the crankcase ventilation system to allow condensation.

[spyderg0d]

After the highway driving and it got to OT. Fuel trims were under 8 and ltft were at 0. The stft only went to 8 when the car was slowing to stop, then went to below 3 when at idle, and also below 3 when driving. Which is where they were before the entire incident. I also think i have to plug the FPR vacuum hose in at the FPR again.
I also thoaght maybe the cel being on before may have contributed. But the cel was for a minor evap leak (less than .5mm i think). So it shouldnt have effected fuel trims or caused a overfueling issue.

[MarcoZandrini]

The only way to find all of the vacuum leaks is to professionally smoke test the intake. Are the oxygen sensors original? BMW (Bosch really) sez yo replace the pre-cat sensors every 100k miles. Be advised that BMW switched to wide band oxygen sensors at some point in the E46 production run. Check realoem to see which are in your car. Also, note that some scanning tools such as OBDFusion need to be set up to read wide band oxygen sensors.

[spyderg0d]

Or.. To gasket seal every possible leak location... Can't be a vacuum leak if theres no where for it too leak. ..
02 sensors.. They are good. Not up for speculation.

[spyderg0d]

Seems the variables have changed. The cel came in last night.. I read the fuel trims to find the long terms have settled around 11.7. It seems the short terms fluctuate dramatically without any correlation to throttle or load.. I think my precat 02s are bad. In any given constant throttle with no load change, the short term can jump from -11 to above 18. But generally, it is around 3. But often will randomly jump from 3 to 8 or 3 to -5. And at any time when the long term fuel trim adjusts to a 12.3 the stft immediately jumps down to negative readings.
Also, the stft do not drop when engine is revved.. Actually, the stft seem to lower when the car is slowing and braking or idle. Only when driving does the trims seem to jump erratically. No misfire codes. Still just the small evap leak code and obviously both banks lean codes.

[MarcoZandrini]

Oxygen sensors are good for 100k miles for narrow band sensors. Old oxygen sensors under-report the amount of unburned oxygen in the exhaust.

[spyderg0d]

Ok.. Ive made a revelation.. My stft do indeed rise with revv. My ltft hover around the 10.7 to 11.7. Stft go to aroun 0 when at idle.. But while decel with brakes, my stft go wayyyy negative.. Im thinking my brake booster is leaking. Il pinch it off later and report.. Its either the booster or a fuel deliver problem or maybe both. Maybe the vacuum from the oil being consumed damaged or made booster issue symptomatic.

[spyderg0d]

Got home, i checked the brake booster valve, and the brake booster, no leaks.. Then i rtv the hose anyway. Now its doing the exact opposite. Now the stft are going down when rev... Wtf... This has gotten crazy agitating.. The quest for vaccum leaks resumes.

[spyderg0d]

After screwing around a bunch more.. My bank 1 stf and ltf have both went down to around 5 to 7.. But my bank 2 ltft still stick around 11 to 14 and stft widely range from 0 to 7.. What on earth leaves just bank 2 so high?

[MarcoZandrini]

The pre-cat sensors need to be replaced at 100k miles. I recommend you buy a CCV that’s made by the supplier to BMW. Go to FCPEuro and enter the data on your car. Then search for the CCV. You’ll get 3 or 4 different options:
- BMW branded ($$$$)
- original equipment (same as above but without the BMW logo; $$$)
- original equipment manufacturer (parts made by a supplier to BMW but not this part ($$)
- aftermarket.

Personally, I’d go with the second option. Also, look up the “02pilot CCV mod.” Basically it adds a vacuum line from the back of the cylinder head to the unused port on the CCV body. This increases vacuum in the CCV body. You are right about the oil catch can-it is an add maintenance task. Your only good option may be the M56 valve cover.

[golf5367]

Go with the “02pilot CCV mod.” its the best change I made to my car and I have never regretted it. I did not do the catch can I went with the straight replacement.

[harrier]

Or.. To gasket seal every possible leak location... Can't be a vacuum leak if theres no where for it too leak. ..
02 sensors.. They are good. Not up for speculation.

1. Please don’t rtv all over. All of the rubber bits combined cost a few hundred bucks and they work. Happy to send a list. If your disa does not resist when removed, replace the oring. Replace all the rest of the rubber.
2. How do you know the o2 sensors are not open for speculation. We’re they replaced with Bosch within the last 100k?
3. You should unbolt and pull your dipstick tube. It is a double-wall design and the narrow chamber between the two walls is where the ccv drains and can easily clog which backs up the whole system. Check there. You can clean it with very strong piano wire. Solvents don’t seem to work. There is an improved design that just dumps the ccv outlet straight into the tube.
4. Why are you deleting the vacuum line to the fpr?
5. Have you replaced the three vacuum lines between the sap and the manifold?
6. Are all the rubber caps in place and intact, including the one on the ccv valve?

[spyderg0d]

1.. Too bad. All of them are new. And rtved for overkill.
2 yes.
3.its not clogged
4.what are you talking about? Not deleted, its there and made aure its connected
5. No connection from sap to manifold. My car has the sap, valve, all on the exhaust manifold with no lines ran to the intake.
6.caps? You mean grommets?. Yes.. All fit well and made sure they are sealed with rtv..

Id like to note my bank 1 trims are at a reasonable but not great level. They stay below 10 combined. My bank 2 trims is floating around still.. So whatever leak is there has to be more so effecring only bank 2. Which doesnt make sense to me.

[spyderg0d]

Just to put the thread to rest... The cvv system has worked 100%... I found the reason for my small evap leak AND higher ltft...
The hose clamp on the fuel pump has literally rotted loose .. It was enough to hold the hose on, for fuel pressure.. But it leaked just a dripple, so little that the gas wouldnt puddle on top of the unit. But i vould see the cleaner section of the unit where the gas had touched and spit shined the surface. I put a new clamp on, my ltft went to .1 my stft float from .5 to -.5 the small evap leak disappeared... All is well and good. Thanks everyone for the help.