[eugene89us]

To my fellow diesel enthusiasts, wanted to share some issues I have discovered running with Mishimoto Oil Catch Can. I installed it around July to August of 2020. It was a compact catch can directly from Mishimoto. I followed all installation recommendations and used Mishimoto hoses to match everything.

During the hot summer months and moderate fall, I caught zero oil. Mostly just residue on the walls of the can, but not enough to catch anything. Roughly every month, I would unscrew the can, clean it up, and wash the filter. When winter came and weather became chilly, the can finally started to condense some things. I had maybe a teaspoon of oil collected from November to now. And about a tablespoon of condensed water. Of course, water vapor is everywhere and would not cause any issues (see water/methanol injection). But I thought, well, even 5mL of oil in the can means 5mL less in my intake or intercooler.

Fast forward this past Monday. I start the car leaving work, and I saw a large plume of smoke. At first I chuckled that some nasty old gasser just passed by. I actually went out of the car, because proximity of smoke looked suspicious. No cars in the parking lot leaving at a time, but my F30 was not smoking from tailpipe. Oh, well, maybe I am overreacting? Then I saw plume of smoke at the traffic light, way more than normal, then I saw a lot of it accelerating onto the interstate - actually I feel some cars changed lanes because of that. Uh oh! Connected my trusty BimmerLink app, it was showing EGTs north of 650C while regen status was OFF!!! Even during regens, EGTs are below 610C. Had one EGT hit 700 at one point! Checked oil level - below minimum on a dipstick (no oil warning yet). Read codes, car there were 4 codes total for high/unexpected EGTs and for oxygen sensor/lambda mismatch values. My car was burning oil, without a doubt. The source of heat and source of O2 sensor issue was oil! The car is at 53,300 miles (read: 3,300 mi out of warranty! What a misery!), always serviced on time, with exceptional oil report at 49K miles (also posted on these forums)! Now I have a car that never consumed a drop of oil before now consumed over a liter of oil!

Next message to be continued...

[eugene89us]

These photos may be sideways, but this is what I got on screenshot while driving. High EGTs in absence of regen and error codes in DDE.

[eugene89us]

Not to make this long story any longer, started to investigate the source of oil leak and consumption. The source was identified as the turbocharger. These turbochargers are not known to be weak, and you hardly ever hear of them failing at only 50K miles. Dealer wanted $1,700 for new turbo replacement alone (for parts). I was going to DIY worst case scenario. Used turbo around $400 to $600, was also considering it.

Started looking into causes of turbo leaks. Two causes were consistently cited on YouTube and other Turbo Repair services. They either said an undersized/kinked oil return line (didn't mess with one, so doubtful) or issues with PCV valve - i.e. increase in crankcase pressure that can lead to poor oil outflow from turbo. Apparently turbos highly depend on good oil outflow, as overflow of oil inside the actual turbo can result it turbo leak. The metal seals are NOT completely oil tight, they also depend on oil flow and slinging action of the pistons on the turbo shaft. Took Mishimoto line off the PCV valve, tried to blow into it - AND NOTHING! Completely stopped up! And that is with monthly cleanings and maintenance. I fear the cold snap (we got our first snow that day in Mississippi when this transpired, so temps at or below freezing all day long) caused the oil to either thicken up inside or something, but the catch can completely stopped up. And there was no oil in the catch can, the brass filter is what got clogged! This caused oil to leak from the turbocharger.

[eugene89us]

The moral of the story: be careful with compact oil catch cans. Also, be careful with Mishimoto, as I contacted them to inquire of this issue happening, and they did not stand behind the product, stating since they don't produce catch cans for BMW DIESELS (they do for some gassers), they cannot assure compatibility or lack of damage.

I followed the installation guide by FaRKle! which is outstanding. One thing I would probably recommend to those that want to have an oil catch can - get a large sized, high flow catch can like Farkle! installed on his. Don't install the compact ones like I did. Although everything fit beautifully and looked nice, it ended up causing more harm than good. And looking back 6 months ago, I wish I never messed with it in the first place!

I was gentle with OEM PCV hose removal when installing the can in July and was able to reuse that pipe hose to make original direct connection between PVC and the intake pipe (as factory). Since catch can may work on gas engines, I will likely sell it on eBay, as I cannot possibly recommend it to my fellow N47 users. I feel with higher compression diesels, we get much more blow by and crankcase pressures than gasoline counterparts, making these compact catch cans unsafe to use. And leaking oil from turbo over time can damage a lot of things, including turbo itself, all emissions components from high temps and sooty oil burn, and possible engine since turbo was leaking from both exhaust and intake sides.

I am hopeful that this experience will not lead to any early failures on my otherwise well-maintained car. I babied it from brand new and I blame myself for entrusting myself to Mishimoto compact baffled catch can. I wish they also stood by the product, but their response speaks volumes. The turbocharger seals are metal piston rings, so I am hopeful they should reseal. I am hopeful that I did not speed up any possible future leaks in my rocker cover or other gaskets that prone to leaks at 100K+ miles, who knows how high the crankcase pressure went and for how long. Thankfully, knowing my car well and being able to tell something was wrong allowed me to identify the issue before car threw any lights or malfunctions (although it did identify an issue in the Error Memory - just not enough to illuminate MIL or drivetrain malfunction warning). Please reach out to me with any questions. But I am running my car without an oil catch can, as I now realize the risk of damage far outweighs the benefit of oil collection - even if it lasted all winter, I may have gotten 10mL of oil in an entire year, since I would not expect much oil in spring, summer, and fall, at least not in warm Mississippi. YMMV.

[eugene89us]

Final post - the leaky turbocharger. Pics may also be sideways since they are taken in portrait mode.

[Watsey]

Unless I'm mis-reading your posts, something doesn't stack up here.

I've had a Mishimoto mini catch can on my 330d for a few years and have never had a problem with it.

Why do you think that high EGTs are linked to the catch can and/or a failed turbo ? High EGTs are typically a result of working the engine hard, i.e. large throttle openings and significant acceleration, which I expect wouldn't have been possible with a failed turbo.

I'm also confused by your mention that turbos "also depend on oil flow and slinging action of the pistons on the turbo shaft". The turbo contained in a housing outside of the engine block and converts some of the exhaust gas energy into rotational energy to compress the inlet air. The turbo has no relationship with the pistons in the engine block.

What is your typical daily mileage ? If you are driving a lot of short journeys, without longer runs to really clear the DPF, it's possible that you can a substantially clogged DPF. Over what total mileage did the car initiate 4 DPF regens ? It's possible that it's trying to clear a partially blocked DPF before it becomes unusable, and that the cause of the DPF becoming blocked is excessively sooty exhaust due to the failed turbo and/or other components. Is it possible that the smoke from the tailpipes is actually ash being ejected ? I know of someone whose DPF 'let go' on the motorway and produced a huge amount of white 'smoke'.

I'm not doubting that you experienced a blocked/frozen brass filter in the catch can (Mishimoto product information does warn of this) but I think you may also need to consider, and investigate, other root causes of the problems that your car is experiencing.

[eugene89us]

Originally Posted by Watsey

Unless I'm mis-reading your posts, something doesn't stack up here.

I've had a Mishimoto mini catch can on my 330d for a few years and have never had a problem with it.

Why do you think that high EGTs are linked to the catch can and/or a failed turbo ? High EGTs are typically a result of working the engine hard, i.e. large throttle openings and significant acceleration, which I expect wouldn't have been possible with a failed turbo.

I'm also confused by your mention that turbos "also depend on oil flow and slinging action of the pistons on the turbo shaft". The turbo contained in a housing outside of the engine block and converts some of the exhaust gas energy into rotational energy to compress the inlet air. The turbo has no relationship with the pistons in the engine block.

What is your typical daily mileage ? If you are driving a lot of short journeys, without longer runs to really clear the DPF, it's possible that you can a substantially clogged DPF. Over what total mileage did the car initiate 4 DPF regens ? It's possible that it's trying to clear a partially blocked DPF before it becomes unusable, and that the cause of the DPF becoming blocked is excessively sooty exhaust due to the failed turbo and/or other components. Is it possible that the smoke from the tailpipes is actually ash being ejected ? I know of someone whose DPF 'let go' on the motorway and produced a huge amount of white 'smoke'.

I'm not doubting that you experienced a blocked/frozen brass filter in the catch can (Mishimoto product information does warn of this) but I think you may also need to consider, and investigate, other root causes of the problems that your car is experiencing.

I am taking about turbo parts when talking of pistons and seals, not engine. This video helped me tremendously, this and one more video is where I got all the naming from.

High EGTs were a result of leaking oil into both intake and exhaust. Oil was being burnt off as fuel, leading to sudden EGT rise.

20 miles each way daily, 70% interstate.

[eugene89us]

Originally Posted by Watsey

Unless I'm mis-reading your posts, something doesn't stack up here.

I've had a Mishimoto mini catch can on my 330d for a few years and have never had a problem with it.

Why do you think that high EGTs are linked to the catch can and/or a failed turbo ? High EGTs are typically a result of working the engine hard, i.e. large throttle openings and significant acceleration, which I expect wouldn't have been possible with a failed turbo.

I'm also confused by your mention that turbos "also depend on oil flow and slinging action of the pistons on the turbo shaft". The turbo contained in a housing outside of the engine block and converts some of the exhaust gas energy into rotational energy to compress the inlet air. The turbo has no relationship with the pistons in the engine block.

What is your typical daily mileage ? If you are driving a lot of short journeys, without longer runs to really clear the DPF, it's possible that you can a substantially clogged DPF. Over what total mileage did the car initiate 4 DPF regens ? It's possible that it's trying to clear a partially blocked DPF before it becomes unusable, and that the cause of the DPF becoming blocked is excessively sooty exhaust due to the failed turbo and/or other components. Is it possible that the smoke from the tailpipes is actually ash being ejected ? I know of someone whose DPF 'let go' on the motorway and produced a huge amount of white 'smoke'.

I'm not doubting that you experienced a blocked/frozen brass filter in the catch can (Mishimoto product information does warn of this) but I think you may also need to consider, and investigate, other root causes of the problems that your car is experiencing.

Here is my DPF, pretty good health. I didn't realize how PCV could affect turbo. That was a learning lesson for me. In the past, would have never guessed it could have cause turbo leak!

[FaRKle!]

Originally Posted by eugene89us

One thing I would probably recommend to those that want to have an oil catch can - get a large sized, high flow catch can like Farkle! installed on his. Don't install the compact ones like I did.

Not going to lie, I checked mine after reading your experience. It's still free flowing.

I've read stories of the bronze filters getting blocked up in the winter when it's cold out and things freeze together.

The high flow catch can uses a much less restrictive filter media. It's a synthetic foam/mesh piece nowhere near as tight as the bronze filter. I think that has more to do with it than necessarily high vs low capacity/sized.

[eugene89us]

Originally Posted by FaRKle!

Not going to lie, I checked mine after reading your experience. It's still free flowing.

I've read stories of the bronze filters getting blocked up in the winter when it's cold out and things freeze together.

The high flow catch can uses a much less restrictive filter media. It's a synthetic foam/mesh piece nowhere near as tight as the bronze filter. I think that has more to do with it than necessarily high vs low capacity/sized.

You're absolutely right, I think it all boils down to the filter media, the bronze filter is indeed the source of the clog. After taking everything apart, the lines remain clear and the catch can (if not for filter) could be checked and cleaned once a year without getting overfilled. However, at a time of my research, I believe the Mishimoto only made one type of compact baffled can with bronze media. In my case, it was certainly a combination of unusual factors that day:

1. our one day snow that comes every 1 to 2 years (last was in 1/2019)
2. the cold temperatures at or below freezing remained the entire day - usually freezing morning always warm up in the afternoon.
3. The car that is parked in much warmer garage during all night cold temperatures and sits in a sunny parking lot during the day, was now parked in the cold for 9 hours at work.
4. The likelihood that these factors led to bronze filter clogging.

If I were a bad owner and did not clean the filter monthly, I would chalk it up to lack of catch can maintenance. But I have done monthly cleanings, complete cleanings that included washing and drying the filter. So yeah, either weekly cleanings may be needed or best to just pick the filter media that is not bronze.

The PCV system was reversed to stock on Wednesday, oil refilled back to full (borrowed from my next oil change stash). As of today (Saturday), EGTs are running within normal limits, no smoking is present, and the oil level remains on maximum. The turbocharger piston ring seals resealed themselves. But of course the plan is to watch the car for the next couple of weeks before I make final determination that car has zero oil consumption as before. For now, I am very optimistic. We are about to embark on a 3000 mi round-trip journey, that will be a great test.

Attached: DDE codes and EGTs about same place on highway as the original post. Compare EGTs now with problem fixed.

[Watsey]

I modified my catch can installation, see attached photo, by adding some taps and a drain tube.

This allows me to easily empty the catch can into a suitable container so the catch can 'never' needs to be removed, and also to check whether the filter is blocked.

The red plug (red circle) is simply pulled out before the drain tube is placed into a drain bottle.

The can drain tap is opened (green circle).

The tap in the CCV return circuit is then closed (blue circle) which causes the crankcase pressure to pressurise the can, thus forcing any contents out through the drain tube.

Once the can has been emptied the drain tube emits crankcase blow-by gases which are easy to see/smell. This makes it very easy to check that he catch can filter isn't blocked.

[eugene89us]

Originally Posted by Watsey

I modified my catch can installation, see attached photo, by adding some taps and a drain tube.

This allows me to easily empty the catch can into a suitable container so the catch can 'never' needs to be removed, and also to check whether the filter is blocked.

The red plug (red circle) is simply pulled out before the drain tube is placed into a drain bottle.

The can drain tap is opened (green circle).

The tap in the CCV return circuit is then closed (blue circle) which causes the crankcase pressure to pressurise the can, thus forcing any contents out through the drain tube.

Once the can has been emptied the drain tube emits crankcase blow-by gases which are easy to see/smell. This makes it very easy to check that he catch can filter isn't blocked.

Sounds like you have safeguards against running with clogged catch can. Mine was a simple set up - just 2 lines, however I would unscrew the bottom each time and release two bracket screws to take catch can out and clean the baffles as well as the filter. I assume 330d is a 6-cyl N57 engine? The 4 cyl N47 is not breathing heavily enough to require a dedicated drain install. However, it was not hard to remove it monthly for cleaning. But at this point, I will go without, since the efficacy of the can is pretty low in our warm climate here.

[gbinckes]

I just installed the same compact catchcan on my 328d, is there a way to replace the bronze filter? I live in So Cal, so not too worried about sub-freezing temps, but the whole reason I installed was to help the engine last longer, especially if I get a tune. Thanks for the heads up!

[Watsey]

Originally Posted by gbinckes

I just installed the same compact catchcan on my 328d, is there a way to replace the bronze filter? I live in So Cal, so not too worried about sub-freezing temps, but the whole reason I installed was to help the engine last longer, especially if I get a tune. Thanks for the heads up!

If sub-zero temperatures aren't a concern, why would you want to replace the bronze filter ?

I've removed the bronze filter in my catch can (the same model being discussed in this thread) to clean it after a year or so and it was still flowing freely. Yes it had some oily residues, because that's the output from the crankcase, but nothing that was restricting the airflow.

[eugene89us]

Originally Posted by gbinckes

I just installed the same compact catchcan on my 328d, is there a way to replace the bronze filter? I live in So Cal, so not too worried about sub-freezing temps, but the whole reason I installed was to help the engine last longer, especially if I get a tune. Thanks for the heads up!

In Sunny California, you will find that the catch can will collect very little since the catch can will get hot and remain hot throughout the drive cycle. The most efficient way to collect oil and water would be when the weather gets cold - not necessarily sub freezing, but when jackets are needed to stay comfortable. That is when the catch can stays cooler than the crankcase vapors and like an air conditioning coil, is able to condense water and oil into the catch can. Another forum member here initially told me that our engines are not truly "heavy breathers" and I was able to prove it, since I caught no oil beyond just light misting on catch can's walls during summer and fall months. Since MS does get cool in winter (30s to 40s F), that is the only time the catch can became efficient. If your neck of the woods always stays nice and warm (60F or over), you will find the catch can to be underperforming. In that case, weigh the risks vs benefits of needing it in the first place. But just like me, I still wanted to see for myself, hence installed it in the summer 2020. Whatever you choose to do, keep the filter clean, do the monthly cleanings. In warm climate, I doubt it will clog as easily as mine did. But the efficiency will be low. Once again, "your mileage may vary."

[gbinckes]

Thanks all for the additional comments, I installed the catchcan because I want to get a tune, was concerned there would be extra oil and gunk slipping through. If the bronze filter and potential clogging is only an issue in cold weather then I think I am in pretty good shape. I have driven less then 500 miles since install, I will check the catchcan contents after about 2k and see what (if any) residue has been captured. I am the kind of guy who will do something because I like the idea, even if it is not as effective as I had hoped, and any excuse to work on a car is good for me Thanks guys!

[Watsey]

Originally Posted by eugene89us

To my fellow diesel enthusiasts, wanted to share some issues I have discovered running with Mishimoto Oil Catch Can. I installed it around July to August of 2020. It was a compact catch can directly from Mishimoto. I followed all installation recommendations and used Mishimoto hoses to match everything.

During the hot summer months and moderate fall, I caught zero oil. Mostly just residue on the walls of the can, but not enough to catch anything. Roughly every month, I would unscrew the can, clean it up, and wash the filter. When winter came and weather became chilly, the can finally started to condense some things. I had maybe a teaspoon of oil collected from November to now. And about a tablespoon of condensed water. Of course, water vapor is everywhere and would not cause any issues (see water/methanol injection). But I thought, well, even 5mL of oil in the can means 5mL less in my intake or intercooler.

Fast forward this past Monday. I start the car leaving work, and I saw a large plume of smoke. At first I chuckled that some nasty old gasser just passed by. I actually went out of the car, because proximity of smoke looked suspicious. No cars in the parking lot leaving at a time, but my F30 was not smoking from tailpipe. Oh, well, maybe I am overreacting? Then I saw plume of smoke at the traffic light, way more than normal, then I saw a lot of it accelerating onto the interstate - actually I feel some cars changed lanes because of that. Uh oh! Connected my trusty BimmerLink app, it was showing EGTs north of 650C while regen status was OFF!!! Even during regens, EGTs are below 610C. Had one EGT hit 700 at one point! Checked oil level - below minimum on a dipstick (no oil warning yet). Read codes, car there were 4 codes total for high/unexpected EGTs and for oxygen sensor/lambda mismatch values. My car was burning oil, without a doubt. The source of heat and source of O2 sensor issue was oil! The car is at 53,300 miles (read: 3,300 mi out of warranty! What a misery!), always serviced on time, with exceptional oil report at 49K miles (also posted on these forums)! Now I have a car that never consumed a drop of oil before now consumed over a liter of oil!

Next message to be continued...

Update :

I had a lengthy, and extremely useful, call with one of the technical team at the Garrett Platinum Partner which supplied the new turbo.

In short :

As the turbo has been on the car for 5K miles he has no doubts (nor do I) that it was installed correctly (manually lubricating it on the bench; pressurising the oil supply after installation; then starting the engine).
At idling rpm the turbo compressor housing is not experiencing boost pressure and can become subject to vacuum from the inlet tract.
A catch can, or a partially blocked PCV or CCV tract, can result in positive crankcase pressure.
These pressure factors can cause oil, which normally returns to the sump by way of a 'gravity drain', to back-up and bypass the turbo oil flinger and rings (not technically "seals"). It then exits the turbo into the hot side (DPF and exhaust) or cold side (charge air), or both. This is one of the reasons that it is not recommended to leave a turbo diesel engine running at idle for extended periods, i.e. warming the engine on cold days.
In the instance that I noticed earlier this week this oil bypass may have caused the DPF to become soaked on oil, or the oil may have pooled in the IC inlet boost pipe, or both.
When I managed to get clear of the traffic congestion and 'exercised' my right foot the EGTs and DPF temperatures would have increased significantly, causing the oil to vapourise and/or be physically burnt off. Hence the cloud of smoke from the exhaust.

I've taken the car out for a 30 mile drive today and stopped to check the oil level every few miles. Zero consumption thus far, and zero smoking.

Conclusions from talking with the turbo tech :

It's unlikely that a new turbo with 5K miles has suffered any significant wear.
Catch cans can cause back-pressure which, although perhaps modest in outright perms, can materially affect crankcase pressure and proper turbo operation.
Oil bypass during extended idling most likely caused the oil consumption and the smoking.
Due to the above, and also the negligible amount of oil intercepted by the can during 25K miles of use (perhaps two tablespoons), I won't be refitting mine. Waste of money.

I hope that helps.

= = =
This week I experienced exactly the same thing as you originally posted.

My car had been in stop-start traffic for around 45 minutes (therefore the engine bay was at full operating temperature) and when I was finally clear of the congestion there was a LOT of smoke under moderate acceleration followed by a warning message...engine oil level is at minimum level.

Checking the oil level, using the dipstick, it's only 25% above the MIN fill level. Both exhaust tailpipes are wet with black oil. It required a top-up of around 750ml to get back to the MAX fill level.

I have checked the Mishimoto compact catch can and all pipework connected to it, and they are not blocked. That said, there is some resistance and I suspect that it's enough to cause some back-pressure in the crankcase.

The car will be going to a specialist BMW indy workshop for a detailed investigation but at this stage the 'shop and I are both focussing on the only route that this quantity of engine oil can enter the exhaust system => turbo seals.

This may be the second turbo failure that my car has experienced since I installed the catch can. I've now removed it (permanently) and have refitted an OEM CCV breather pipe. My experience of these catch cans, during 25,000 miles use, is that they collect MINIMAL amounts of oil. In cold weather they do tend to create condensate but of course this is just water. My experience is that they are a waste of time, and possibly cause very expensive consequential damage.

I can only hope that, like yours, this was a one-time event and that the new turbo (which has only done 5,000 miles since it was fitted) reverts to normal operation.

For anyone running a catch can on a diesel, you have been warned !

[eugene89us]

Thanks for your update, Watsey

Just to hopefully give you some hope, since I reversed the catch can at 53k miles, the car has consumed zero oil between my 10k mile oil change intervals. I continue to run LL12-FE 0W-30 oil that is recommended for us in North America, I get BMW-branded oil. Planning to send another sample to Blackstone at the next oil change.

The car is currently at 94,000 miles, so almost doubling mileage since my issue with the catch can. With no oil consumption, I am certain no turbo damage was caused by it as I discovered it early when it first got clogged, turbo seals are doing their job once again. I am certain as your PCV starts to work normally with reversal of this catch can fiasco, your turbocharger will reseal. Please keep us posted.

And another warning to others - revert these catch cans, especially compact ones. They do very little to help with oil catching, while they risk a lot. Good luck!

[Watsey]

Originally Posted by eugene89us

And another warning to others - revert these catch cans, especially compact ones. They do very little to help with oil catching, while they risk a lot. Good luck!

I completely agree with the above.

The turbo is no longer consuming any oil - it seems conclusive that the catch can was the cause of the problem.

The engine is running a lot smoother as well. There was a real rough spot at around 3K rpm, and that’s gone now.

Crankcase pressure, as a result of restricted airflow through the catch can (especially those that have an internal filter), can cause significant problems and shortened lifespan for turbos. Now I understand that, I’d never install one again.

[Rickyrozay17]

Hi all,

Hope you are well

I have a 2014 218d with the N47 engine that has burnt 2 litres of oil in 1400 miles. The car has 129,000 miles currently and seems to be burning an obscene amount of oil. Could you provide me with solutions?

There is sweating on the intercooler charge pipe and there is also oil around the oil filter housing. The main dealer has said that I need a new engine. Im just wondering is there anything else I can do the save the car?

[Watsey]

Originally Posted by Rickyrozay17

Hi all,

Hope you are well

I have a 2014 218d with the N47 engine that has burnt 2 litres of oil in 1400 miles. The car has 129,000 miles currently and seems to be burning an obscene amount of oil. Could you provide me with solutions?

There is sweating on the intercooler charge pipe and there is also oil around the oil filter housing. The main dealer has said that I need a new engine. Im just wondering is there anything else I can do the save the car?

That’s a very high oil consumption.

129K miles isn’t high for a modern engine. If the engine hasn’t been abused, and has been well maintained, I’d focus on the turbo as the likely culprit.

Removing the exhaust and charge air pipes will make it possible for a visual check for the presence of oil. Starting the engine, and letting it idle, will show whether the turbo is leaking when it is receiving an oil feed.

Whether this is a DIY job, or something to be done in the shop, is obviously your call.

[TurboWeasel]

Yeah get a leak down test done first before going down the new engine route. A lot of dealers don't realise the turbo is a source of oil consumption.