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Discussion Starter · #1 ·
I am thinking of fitting a catch can & have all the parts on my list to purchase, my question is a simple one - Does it actually make a noticeable difference and is it worth the effort?
Thanks in advance :thumbup:
 

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Alfa 159 2.0 JTDm Lusso 6sp.
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Mine only caught a tiny amount of oil in the first couple of months of use....but that's a tiny amount of oil that did not go into my intake, mix with the egr gases to form that nasty tar. Also caught about 5mm of water in the bottom of the can...probably that gets driven out of the oil and from the crankcase walls after a cold start...again probably better caught than ingested! I'm told that the Euro 4 models give off more oil than the Euro 5 models...mine is five. Even if they only catch a little it has to be a benefit.....I expected that mine might breathe a little more oil because of my high miles......my rings cant be that worn then!
 

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Similar experience, fitted one of the large hollow ones off e-bay (adapted with wire wool and copper pipe), but caught virtually nothing (only about 20/25% full after 15,000 miles). Some people fitted a Rutland motors catch can (search for the long thread), which seemed much more effective e at removing oil, but I got the impression from the thread that they didn't last long without breaking.
No real performance improvement from it, but a little peace of mind.
 
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I had a Rutland one fitted, it caught a decent bit of oil over time. After a year or 2, something went wrong and it blew a hell of a lot of oil out of the dipstick a couple of times, oil all over the engine and road. The culprit was caught and binned, but I think others have got on okay with it.
 

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Discussion Starter · #5 ·
I was think along the same lines, buy a baffled unit and fill it with a s/steel scrubber or two, I’ve found one with a drain to the side which would make it easier for draining and could be modified to run the drain to a better location?
I’ll keep my options open for now.
 

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The problem with the rutland ones is that they don't flow enough air. A heavy breathing diesel with high boost pressures can pass a surprising amount of air through a breather pipe. Hence the huge diameter of them usually compared to a petrol engine.

If that pressure can't get through the tiny rutland filter then it will blowing out of other gaps! Worst case scenario it will blow out through the crank shaft seals and soak your clutch. Best case it will pop the oil dipstick up and escape out of there instead.
 

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I bought the £12.50 red pne of ebay, its amaxing quality for the price!

Im going to baffle it myself and i have ordered uprated hoses as the standard are just water hose pipe
 

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Sounds like the one I fitted. I also upgraged the hoses to silicone ones.

Sorry about the fuzzy pic....not sure why that happened...its clear until I upload it!!!
 

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Discussion Starter · #10 ·
Put a link to the one you bought, I assume the hoses are 16mm I/D x 21mm O/D silicone hoses?
 

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Currently I use a oil catch can that consists of standard 1/4" air filter, like used on air compressors to remove moisture from air lines, with my own filter element within.
On the bottom of the can I placed a ball valve so I can empty it easily.

There is a estimated 5-10mm layer of oil in it every 1000km.
It still passes oil but at least something is blocked.

If you want to buy one I would not recommend the ones which uses a brass filter.
It blocks quit easily and you don't want to have a build up of crankcase pressure because of this.

Select one which is not to restricting, even though the pipes to the intake have a quite large internal diameter, at the oil separator at the back of the engine there is a 6mm restrictor.
So that's the bottle neck, and the reason I use an 1/4" air filter since its roughly the same diameter.

I'm experimenting with different versions in order to block all the oil or at least most of it but no real improvement yet.
If I found something promising I will share it.
 

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yeah thats the same one

what size hose ID did you go for?
Put a link to the one you bought, I assume the hoses are 16mm I/D x 21mm O/D silicone hoses?

The hoses are two different sizes. The fittings on the can are 15mm which matches fine with PCV outlet pipe.....but the connector to the intake tube is 21mm so I bought 15mm id and 21mm id tube and bought a 21 to 15mm reducer to go half way along the tube between the outlet of the can and the inlet to the intake tube. It's the blue thing you can just about see half way along the return tube.
 
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Nice....then you can revel in the smell of the smoky PCV oil vapour coming out of that breather an being sucked into your cabin!!
 
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dont bother, just pull the pipe out, plug up the intake with a rubber bung and fit a breather filter in place of the pipe.
Hmmm...Unless I've missed something on recent DVSA standards is it not STILL AN MOT FAIL to vent any fumes into the atmosphere via a breather filter from the crankcase, the Emission control regulations are clear on this... Please correct me if I'm wrong here but what is the point of going through the whole process and expense of fitting an oil catch tank setup and then screw it up for the next MOT with a breather filter?
 

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Letholdus is in New Zealand.....prob very different MOT laws there.
 

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Hmmm...Unless I've missed something on recent DVSA standards is it not STILL AN MOT FAIL to vent any fumes into the atmosphere via a breather filter from the crankcase, the Emission control regulations are clear on this... Please correct me if I'm wrong here but what is the point of going through the whole process and expense of fitting an oil catch tank setup and then screw it up for the next MOT with a breather filter?
I have the rutland one fitted and haven't had any problems, I don't agree with them not flowing enough air, this is basically an airline filter and will easily exceed the flow rates from the engine in this location, the only issue I can imagine is if the filter gets clogged, again I think this would be hard the way it has been designed. It is also a nice neat installation which is a big plus for me. I've driven around 12000 trouble free miles with mine fitted, the only change I made was I fitted some stainless gauze (one of those kettle scale catchers fitted perfectly) to try to increase the capture rate.
 
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