Question re: CCV on E46 318i
Discussion
Hi all,
I was recently replacing my rocker/valve cover gasket when unfortunately the CCV breather hose that comes from valve cover shattered as it had become so brittle. You'll imagine how pleased I was to see that it ran down behind the intake manifold into the depths of Hades.
I'm not mechanically minded, but have become being fairly competent and replaced lots of stuff myself in the past such as the water pump and cooling system; but alas when I attempted to change the CCV I was thwarted by two pretty much inaccessible T25 screws which hold the intake manifold to a bracket that can only be accessed from underneath the car if you are Reed Richards. I gather this repair is easier on some of the 6-pot engines, but not so on the N42.
To this end, I am booking the car in to a local indie (Atlas Auto Services in York) once some more parts arrive to have the brittle pipes and CCV replaced (and am gonna get a bunch of other bits done at the same time including the timing chain).
When I first shattered the pipe, I didn't use my car as I had no idea what the pipe was for; however since then I have obviously identified it as being part of the CCV, and as such the car does run, but has low oil pressure and stalls quite easily.
Question: In the image below, it is the pipe from the valve cover (labelled A) that is currently broken,and thus the CCV system is not operating correctly, and leading to the low oil pressure.
What would happen if I was to temporarily put a bung in the outlet coming from the valve cover? I'm thinking this would resolve the oil pressure issue, but obviously I don't want to completely wreck my engine. I just need a temporary fix until the car is in the garage next week for the proper fix.
Please be gentle, I appreciate this may be a stupid question, but I honestly don't know that much about how engines work; I'm just a follow the DIY bolt-on/bolt-off kinda guy.
Cheers,
DS
I was recently replacing my rocker/valve cover gasket when unfortunately the CCV breather hose that comes from valve cover shattered as it had become so brittle. You'll imagine how pleased I was to see that it ran down behind the intake manifold into the depths of Hades.
I'm not mechanically minded, but have become being fairly competent and replaced lots of stuff myself in the past such as the water pump and cooling system; but alas when I attempted to change the CCV I was thwarted by two pretty much inaccessible T25 screws which hold the intake manifold to a bracket that can only be accessed from underneath the car if you are Reed Richards. I gather this repair is easier on some of the 6-pot engines, but not so on the N42.
To this end, I am booking the car in to a local indie (Atlas Auto Services in York) once some more parts arrive to have the brittle pipes and CCV replaced (and am gonna get a bunch of other bits done at the same time including the timing chain).
When I first shattered the pipe, I didn't use my car as I had no idea what the pipe was for; however since then I have obviously identified it as being part of the CCV, and as such the car does run, but has low oil pressure and stalls quite easily.
Question: In the image below, it is the pipe from the valve cover (labelled A) that is currently broken,and thus the CCV system is not operating correctly, and leading to the low oil pressure.
What would happen if I was to temporarily put a bung in the outlet coming from the valve cover? I'm thinking this would resolve the oil pressure issue, but obviously I don't want to completely wreck my engine. I just need a temporary fix until the car is in the garage next week for the proper fix.
Please be gentle, I appreciate this may be a stupid question, but I honestly don't know that much about how engines work; I'm just a follow the DIY bolt-on/bolt-off kinda guy.
Cheers,
DS
- Picture lovingly borrowed from the 'net.
So the CCV system is design to ensure that the crankcase and cover are always in vacuum (albeit at different levels depending on engine speed etc). Vacuum is preferred over positive pressure due to many things including oil seal longevity so the design of this system is to ensure vacuum.
Hence the common test on these engines as well as M52/M54 is to do the bag test over the dipstick and oil filler - the bag should be sucked inwards (sign of vacuum) and if it inflates the bag (positive pressure), then it is a sure sign of CCV failure.
There is no restriction between the valve cover pipe and the crankcase vent pipe and they are both at the same level of pressure / vacuum. The regulator is designed to maintain a vacuum in the swirl chamber.
So when the engine starts and the swirl chamber is at 0 Pa the regulator is open, due to the high vacuum at idle, the gases are drawn up through the connecting line to the inlet manifold and back in. After all the gases have left, a vacuum is created in the swirl chamber and the regulator closes. As the engine runs more blowby gases reduce the level of vacuum (increasing the pressure) - the regulator reacts and seeks to create another vacuum courtsey of the inlet vacuum and opens up again.
A by product of all this blowby gas is the fact that the gas picks up oil molecules in the process and of course this is unwanted in the inlet manifold as it would resulting in clogging up and oil consumption by the engine. So the design of the swirling chamber is such that it captures droplets of oil on its walls allowing a drip drain back to the sump whilst the oil free air continues to the inlet manifold.
In your case as the top vent pipe is missing and so the regulator will be stuck open in an attempt to maintain vacuum which it cannot do. The reason for stalling is that the ECU has most likely sensed a vacuum leak.
I would just wait until it is resolved with new hoses.
Hence the common test on these engines as well as M52/M54 is to do the bag test over the dipstick and oil filler - the bag should be sucked inwards (sign of vacuum) and if it inflates the bag (positive pressure), then it is a sure sign of CCV failure.
There is no restriction between the valve cover pipe and the crankcase vent pipe and they are both at the same level of pressure / vacuum. The regulator is designed to maintain a vacuum in the swirl chamber.
So when the engine starts and the swirl chamber is at 0 Pa the regulator is open, due to the high vacuum at idle, the gases are drawn up through the connecting line to the inlet manifold and back in. After all the gases have left, a vacuum is created in the swirl chamber and the regulator closes. As the engine runs more blowby gases reduce the level of vacuum (increasing the pressure) - the regulator reacts and seeks to create another vacuum courtsey of the inlet vacuum and opens up again.
A by product of all this blowby gas is the fact that the gas picks up oil molecules in the process and of course this is unwanted in the inlet manifold as it would resulting in clogging up and oil consumption by the engine. So the design of the swirling chamber is such that it captures droplets of oil on its walls allowing a drip drain back to the sump whilst the oil free air continues to the inlet manifold.
In your case as the top vent pipe is missing and so the regulator will be stuck open in an attempt to maintain vacuum which it cannot do. The reason for stalling is that the ECU has most likely sensed a vacuum leak.
I would just wait until it is resolved with new hoses.
Regarding the inaccessible torx bolts, when me and a mate changed the ccv valve on his Compact we found the easiest thing to do was to actually unbolt said inlet manifold bracket as the bolts on that are far easier to get to than the torx's (but are still a pain in the arse!) which allowed us to lift the manifold up far enough to get a decent tool on to the torx's. We then replaced the torx's with standard hex head bolts upon reassembly to make any future dis-assembly easier.
Gassing Station | BMW General | Top of Page | What's New | My Stuff