Had time this morning to clean out the oil catch cans on the 335i N54. The last time was in January 2018. I have done about 1500ks since then.
But let me start from the beginning.
I bought this car in 2009 and installed the BMS Oil Catch Can very soon after driving it out the show room. This OCC was fitted on the (high side) of the PCV system. This was the same OCC I had on my previous 335. The BMS advert at the time was convincing but did not entirely turned out as advertised. This was the add:
After about two years of ownership the BMS OCC did collect a good amount of blowby oil but I noticed that oil was still blowing through and gunking up the intake valves. However, the excessive oil in the intercooler pipes, charge pipe and vanos system was significantly less and over time hardly traceable with the BMS OCC in place. Its important to note that the high side oil catch can only collects blowby when the engine is in boost. So if you stay off boost there wont be much to collect.
I then decided to fit a second oil catch can, the "RB external PCV kit", to completely prevent oil buildup on the intake valves. But before doing that a carbon clean of the intakes were done by a very talented technician Riyaan Cornelius in Cape Town. Thanks again Riyaan.
The RB external PCV and OCC is inserted into the (low load) system. Most of the contamination found on intake valves is due to low load oil accumulation during idle and normal daily driving circulating through the internal PCV valve and into head ports and then builds up as gunk on the intake valves. The RB kit includes an external RB PCV valve, Mishimoto Oil Catch Can with a slow filtration filter, throttle body adapter assembly, head plugs and oil piping. I modified the kit since but these are the essential items.
Here are pix of the low side pcv conversion. Please note I have made some major changes to this design but this is essentially the idea.
Next up was plugging the head ports. This is not an easy job and one has to be careful not to crack the head while doing this but I wont deny its fun tackling it. Each person will have his own style of going about doing this. I took my time. :smilebounce:
Please note the plugging of the head ports is not necessary. RB explains this very well on the sales page of the kit: Plugging the ports "rules out vulnerabilities in the valve cover gasket and valve cover itself meaning it is no longer a "worry"; but plugging the head ports is NOT required - but once again we suggest considering it as soon as possible to get the full benefits".
For those wanting to sell their cars in the far future, this modification is reversible.
All the oil head ports blocked off.
Here is a view of the bottom of one the head ports.
After approximately 1500ks this is the result:
Look at this comparative collection. The RB low side can on the left is over half a can full while the BMS high side on the right collected just a little as expected. I am convinced I made the right decision fitting both OCCs.
I definitely need a larger low side OCC :thumbs:
Since doing the low side external pcv and head ports I have checked the intake valves and they have remained cleaned. I subsequently fitted port injection which will further help keeping those valves clean :thumbs:
The carbon doctor website explains the port injection benefit very well as it relates to carbon cleaning: "Due to modern unburned hydrocarbon regulations, vapors from the crankcase are usually vented into the intake stream in order to prevent oil droplets from escaping through the exhaust. In a port injection traditional engine, these droplets are ‘washed off’ the neck of the intake valve by a relatively constant stream of fuel. In a DI (direct injection) engine, the gasoline doesn’t touch the intake side of the valve. As a result, the droplets have a tendency to bake onto the valve and cause significant carbon deposits causing a reduction in performance, rough idling, difficulty starting and eventually bad sealing of the valves".
And finally fitted larger turbo oil drains a year ago. But that's an entirely new topic:
But let me start from the beginning.
I bought this car in 2009 and installed the BMS Oil Catch Can very soon after driving it out the show room. This OCC was fitted on the (high side) of the PCV system. This was the same OCC I had on my previous 335. The BMS advert at the time was convincing but did not entirely turned out as advertised. This was the add:
After about two years of ownership the BMS OCC did collect a good amount of blowby oil but I noticed that oil was still blowing through and gunking up the intake valves. However, the excessive oil in the intercooler pipes, charge pipe and vanos system was significantly less and over time hardly traceable with the BMS OCC in place. Its important to note that the high side oil catch can only collects blowby when the engine is in boost. So if you stay off boost there wont be much to collect.
I then decided to fit a second oil catch can, the "RB external PCV kit", to completely prevent oil buildup on the intake valves. But before doing that a carbon clean of the intakes were done by a very talented technician Riyaan Cornelius in Cape Town. Thanks again Riyaan.
The RB external PCV and OCC is inserted into the (low load) system. Most of the contamination found on intake valves is due to low load oil accumulation during idle and normal daily driving circulating through the internal PCV valve and into head ports and then builds up as gunk on the intake valves. The RB kit includes an external RB PCV valve, Mishimoto Oil Catch Can with a slow filtration filter, throttle body adapter assembly, head plugs and oil piping. I modified the kit since but these are the essential items.
Here are pix of the low side pcv conversion. Please note I have made some major changes to this design but this is essentially the idea.
Next up was plugging the head ports. This is not an easy job and one has to be careful not to crack the head while doing this but I wont deny its fun tackling it. Each person will have his own style of going about doing this. I took my time. :smilebounce:
Please note the plugging of the head ports is not necessary. RB explains this very well on the sales page of the kit: Plugging the ports "rules out vulnerabilities in the valve cover gasket and valve cover itself meaning it is no longer a "worry"; but plugging the head ports is NOT required - but once again we suggest considering it as soon as possible to get the full benefits".
For those wanting to sell their cars in the far future, this modification is reversible.
All the oil head ports blocked off.
Here is a view of the bottom of one the head ports.
After approximately 1500ks this is the result:
Look at this comparative collection. The RB low side can on the left is over half a can full while the BMS high side on the right collected just a little as expected. I am convinced I made the right decision fitting both OCCs.
I definitely need a larger low side OCC :thumbs:
Since doing the low side external pcv and head ports I have checked the intake valves and they have remained cleaned. I subsequently fitted port injection which will further help keeping those valves clean :thumbs:
The carbon doctor website explains the port injection benefit very well as it relates to carbon cleaning: "Due to modern unburned hydrocarbon regulations, vapors from the crankcase are usually vented into the intake stream in order to prevent oil droplets from escaping through the exhaust. In a port injection traditional engine, these droplets are ‘washed off’ the neck of the intake valve by a relatively constant stream of fuel. In a DI (direct injection) engine, the gasoline doesn’t touch the intake side of the valve. As a result, the droplets have a tendency to bake onto the valve and cause significant carbon deposits causing a reduction in performance, rough idling, difficulty starting and eventually bad sealing of the valves".
And finally fitted larger turbo oil drains a year ago. But that's an entirely new topic:
raise:
