Hi NAMers.

OK, I've read about a bazillion posts about OCCs and what they do and what they prevent. But I can't help wondering why, if the effects of micronized oil droplets and oil vapor are so problematic, this is not a component engineered into the engine system? Could the recirculation of the oil vapor/droplets be of some benefit or is this simply an issue of "dumbing down" the engines for the general public who want "zero maintenance" vehicles?

You would think that with the brain-trust of hundreds (thousands?) of engineers at BMW (and other car companies), if this were a real problem, all cars would come with an OCC as standard OEM equipment (like a car's air filter, oil filter, etc.).

Ready to be educated! I'm quite interested in hearing your thoughts.

Thanks all.

Dan

 

Just change your oil = don't listen to Mini = Once a year will kill your Car !!! Change every 8-10 miles !

 

Thanks. So your view is that the OCC has a neutral effect if other proper engine maintenance is followed (e.g. frequent oil changes, Seafoaming occasionally, etc.)?

 

My OCC has kept my intercooler clean. It seems to trap most of the oil vapor before it coats the inside of the intercooler.
I pulled the intercooler to see if it had much oil like others have had. But after 60k there was very little that came out when I cleaned the intercooler. I take this as a sign the OCC is trapping most of the oil vapor rather than coating the inside of my intercooler.

 

8-10 miles! I'd have to stop and change the oil on the way to the store to buy oil! Then I'd have to buy twice as much oil, so I could stop on the way home to change the oil again!

I think Mini's would tolerate a longer oil change interval than that!

Dave

 

That's what I thought too. I'm going to assume they meant 8-10K.

 

degrades performance a little bit, but not a lot. I datalogged the effect on an R53.

The reason they aren't on most production cars is that they require maintenance, and most people don't do maintenance.... It's like factory water injection. It can help with turbo cars, but owners would let them run dry then it's not good for turbo cars!

Here's my take, and it's just mine. I don't run one on the R53 as I don't want to deal with it. If I had a turbo Prince engine, I'd run one to extend the amount of time it takes to build up carbon on the intake valves.

Matt

 

Thanks Matt.

That's what I figured. Car manufacturers are balancing the pros and cons of improving engine performance against ease of use for the general public (as well as risk/benefit - I can only imagine how many engines would be totally destroyed by owners not draining the cans and having liquid oil sludge sucked into the pistons).

I guess in the end, convenience wins out over the slight improvement in performance/function.

 

It is also for environmental reasons. I mean, back in the day, any kind of oil vapor simply vented into the atmosphere. So instead of that, they recirculate it and expect it to be burned up. But most of it settles in the intake tract and nobody can really tell the difference. Oil catch cans could also leak (mine did) and the simpler option for manufacturers is recirculation.

I took my oil catch can off about 10,000 miles ago (it broke because of repeated squashings - vacuum pressure was collapsing the bendy can under throttle after a while)

I haven't really noticed anything different without it. But I bet if I pull the intercooler there will be oil in it.

 

The benefit (very small) of an OCC far outweighs the 12.5 seconds it will take to remove one and drain it. Mine is mounted by 1 nut and 2 hoses, that dont even use clamps. If i had to empty it once a week for a year, I's still have less than 2 hours invested in maintaining it.

For mainstream cars, as has been stated bad idea because they can cause engines to go boom without maintenance. BUT for us crazies who know headlights don't have fluid, not having one is causing MORE maintenance than having one.

 

The amount of oil and other stuff will vary greatly depending on the car. Some have seen as much as a cup of oily stuff in the same time as others have seen only a few Tbs.

I prefer a clean intake and IC so I have one on mine.

 

It seems the majority of responses are from those with a turbocharged MCS. I can see how keeping an oil film out of your IC would be a good idea. Since the regular MC doesn't have this issue, I assume that the OCC doesn't provide as much benefit. Perhaps, as an earlier post stated, it just keeps them cleaner for a little longer than without.

 

Oh, I'm sorry, i missed that your MINI was N/A. Yeah, in that case the OCC would be extremely little benefit.

 

If you don't plan on keeping your MINI then don't bother with an OCC. If you do then consider an opinion based on experience rather than the assumption that if you have an NA engine it's of no benefit. These Prince engine's send a heck of a lot more crap through the PCV than the Tritec's do. I check my OCC every three weeks and I poured this out the other day.


That's after about 1000 miles and it's been that way for the last 110k. Have a look at this short vid and you''ll understand why.

 

The point of the OCC is to keep your Turbo, IC, and intake track clean. Mostly the Turbo and IC, so that they can do thier job at 100%. But if you are running a naturally aspirated car, you wont have a turbo or IC to keep clean, so now you have some hoses to keep clean. Not sure the fine oily buildup would cause much of a problem. After all, the engine is designed to run like that.

 

OCCs are of so little benefit that I doubt that anyone can actually document and performance delta at all. When I looked at the effect of clean vs dirty on R53 ICs, there was a very slight difference in air density post IC, and no difference in performance. The idea of re-routing some blow by and water vapor into the intake isn't a bad one, and keeps all the crap out of the atmosphere or where ever the stuff ends up.

But I'm sure that they will be good sellers and many will be happy to have them. Vive la difference!

Matt

 

You are still letting all of that oily crap go thru your cars intake system.....wouldn't you rather have just clean air?

 

I don't think this is at all about performance, it is more about what goes into the engine and whether we prefer to do a little more maintenance or just allow the engine to combust these products.

Me, I prefer to do a little more maintenance than to just sit back and let less than optimal air be ingested.

 

Do you remember those adds where Volvo or whomever was claiming that the air out the exhaust pipe was cleaner than the air going into the car? The stuff gets burned in the combustion chamber then goes through the converter. Hydrocarbons and other large molecules get broken down to mostly CO2 and water.

Cars with PCV system often get several hundred thousand miles out of an engine. I'm not sure that one can claim that it's really a long term negative to the health of the engine. Really, if you have a race car that's on the track all the time, then maybe it's a good thing to run. For a street car? I'm not so sure that there is a real big benefit for non direct injection engines.

If you want to run one, fine do it. But don't kid yourself on either the health of the engin or the performance benefit that you will get.

Matt

 

I guess I am not making myself clear......I don't want oily, watery, gunky stuff going thru my intake system. I would rather spend a bit of time emptying a can than allowing that same material to coat my intake system. I don't care about the performance or the tailpipe emissions, only about keeping the engine cleaner. Same reason I spend money a good detailing products, buy premium gas, get quality synthetic oil, and vacuum out my car on a regular basis.

 

Im all about keeping the cylinders clean. Ever seen an audi with blow by from the turbo? with an un-healthy amount you get detonation.... with detonation you get to re-build. I know this is not a mini, but same theory.... Im just a little burnt after knowing what "can or could" happen.

 

you want pristine intake? Fine, have at it. I don't have a problem with it. Keep in mind that catch cans don't eliminate the problem, they just reduce it so that it takes a longer time for the same thing to happen. Oil gets past the rings and gets burned up and leads to carbonizing the combustion chamber as well, it's a question of the time it takes to happen.

Look, if having an OCC makes you happy, do it. But don't buy all the BS that they are marketed for. Heck, there are even catch cans sold with no internal condensation surfaces or baffles in them so they don't do much at all!

So, what will it do? It will slow down, but not eliminate, the burning of blow by products. Will it make a lot of power? No. Will it really enhance the life of the engine? Not if your engine isn't direct injection. And even then, it will delay, but not eliminate, the need for valve/intake cleaning.

I'm not telling people to buy them or not to buy them. All I'm trying to do is let people know what's really going on so they can make an informed decision. Whatever decision you or anyone else makes is fine by me. you have your value metrics, I have mine. It's OK if they are different. But really, making the decision by using fact instead of fiction should lead to happier campers all around.

Matt

 

I have enough personal experience to make an educated decision on my own, thank you. I do agree, however, that the way these types of things are marketed is less than accurate. To me there is no harm in delaying what "could" be inevitable. If anything, who wants to clean a dirty intercooler more than they have to?

 

Getting back to the op's question on the need for an OCC on a Justa, I think w/o the turbo or supercharger, their is not real need for it.

 

Thanks Matt and all the others.

You all raise valid points about the reasons why a person would like to run an OCC and why someone would choose to forego it. Matt, I'm a bit confused in your references to non-DI engines. Aren't all Minis DIs or did I miss something? Is the 2009 MC engine no longer direct injection?

I'm off to consult the manual...