Photo by RVAE34 | CC BY-NC-ND 2.0
If you’ve been keeping up with the news on GDI engines (Gasoline Direct Injection), you’ve probably seen that these engines have a major design flaw.
Early GDI engines overlooked the importance of preventing carbon buildup on the intake valves and suffered from misfires once the carbon buildup was too much.
However, GDI engines are not the only ones affected.
Turbocharged engines produce a lot of blow-by once you really get on the gas, therefore a lot of oil vapor from the crankcase is being sent to the intake to be burnt. Carbon buildup is something you definitely don’t want in your intake system as it will lead to expensive repairs in the long run.
Luckily, oil catch cans are the answer to that problem. Once you empty your oil catch can for the first time, you will be shocked at the nastiness that is entering your car’s intake.
Benefits of Running an Oil Catch Can on Turbo Engines
An oil catch can is a very simple device that does just that – catch oil. To be more specific, it catches motor oil from the vapor coming out of the crankcase.
Even though a catch can is simple in design, it does make a BIG difference for direct injection and turbo diesel engines.
You see, modern internal combustion engines (due to increasing emission regulations) are forced to burn oily crankcase vapors because venting outside is illegal. While this design does help the environment, it certainly doesn’t help your car’s engine.
No matter if the engine is fresh from the factory or has been running for half a million miles it has some amount of blow-by. Because of blow-by, nasty combustion byproducts (contaminants) enter the crankcase. Combined with air pressure created by the moving pistons, contaminants mix with oil mist, exit through a pressure relief hose, and get sent into the intake to be burnt.
These oily contaminants stick to the intake manifold, intercooler, turbo, and intake valves. Not only do they coat the intercooler and the intake manifold which results in reduced airflow and air cooling – they ultimately stick to the intake valves and solidify.
Once the oil solidifies on the intake valves, the engine shows a loss in power and fuel economy. If it gets really bad, the engine starts knocking or detonating.
Direct injection and turbocharged engines produce significantly more contaminants, which could lead to oil residue solidifying and damaging the turbo.
The 3 Best Oil Catch Cans for Turbo
Best OverallMann-Hummel ProVent 200
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Best ValueMann-Hummel ProVent 200
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Honorable MentionVincos Universal Aluminum Oil Catch Can
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Mann-Hummel ProVent 200 – Best Overall
Unlike its cheaper competitors, the Provent 200 features German engineering, specially designed filters, and pressure relief valves. They should come standard from the factory on turbo-diesel engines!
The ProVent 200 doesn’t make any compromises. It was designed by Germany’s leading filter manufacturer Mann-Hummel to capture up to 98% of all the oil droplets found in blow-by.
The 1-inch diameter of the inlet and outlet means that the ProVent 200 does not reduce the flow rate of the PCV system, maintaining the same design performance as the OEM manufacturer.
Cheap oil catch cans have small inlets/outlets, which reduce flow and cause back-pressure in the crankcase. Rubber crankcase seals are not designed to hold pressure; therefore, they could start leaking oil.
In addition to large inlets/outlets the ProVent 200 has 2 pressure relief valves, while again, most catch cans on the market don’t feature relief valves at all. One for the inlet to relieve high pressure and one for the outlet to relieve vacuum. Pressure relief valves are extremely important if the filter gets blocked from not cleaning it.
Finally, the ProVent 200 is the only catch can on the market that utilizes an actual specially engineered membrane filter that captures particles up to 0.8 microns – that’s 1/10 of the size of a red blood cell!
Most catch cans on the market feature steel gauze at best if anything at all. While they do catch oil mist droplets, they certainly do not properly catch contaminants from entering the intake system.
All-in-all, if you don’t mind paying more for a catch can, you should look no further than the ProVent 200 as the competing catch cans don’t even come close. It’s definitely the safest option for the long term – if your engine could talk, it would definitely thank you!
- Captures up to 98% of oil droplets
- Special filter captures particles up to 0.8 microns
- Features 2 pressure relief valves
- Large inlets/outlets allow maximum flow
- Filter is a bit expensive and has to be changed regularly
Mishimoto MMBCC-CBTWO-XLBK XL – Best Value
The Mishimoto is one of the few catch cans on the market that feature an actual working filter that does not need replacing and is 100% washable.
Made from 100% 6061 aluminum billet, the Mishimoto oil catch can is very compact and durable. The catch can features a 50-micron bronze filter and is fully washable, unlike the ProVent 200 which needs periodic filter changes.
In addition to an excellent bronze filter, it also features internal baffles and air dividers. A single large perforated baffle cools the oil and prevents it from splashing around during racing conditions, while the two additional smaller air dividers direct the flow and provide a surface for the oil mist to condense and form drops.
The catch can has a drain plug on the bottom but is also very easy to empty by unscrewing the lid by hand. The addition of a universal bracket gives the ability to mount the catch can at various different angles.
In conclusion, while the Mishimoto catch can is not the cheapest, it will certainly pay for itself fast as you won’t need to buy expensive filters. Combined with an excellent 50-micron filter, the Mishimoto oil catch can is hands down the best bang for your buck mod you can do to protect your engine.
- 100 % washable and does not require buying filters
- Has internal baffles to keep the oil from splashing
- Compact design with a universal mounting bracket
- An all-aluminum design means the catch can will easily outlive the car
- The ½ fitting could have been metal instead of plastic
Vincos Universal Aluminum Oil Catch Can – Honorable Mention
While being in the cheaper price range, the Vincos oil catch can is fully washable and certainly gets the job done.
Made from aircraft-grade 6061 aluminum billet, the Vincos universal oil catch can functions well and looks even better. Its fully TIG welded design, in addition to rubber o-ring gaskets means that the can stays leak-free for years to come.
It features a handy screw-on dipstick for an easy way to check the oil level inside the can. The Vincos catch can is also compatible with older cars without a PCV system as it comes with a breather filter.
While it does not feature a filter, the Vincos catch can utilizes two baffles to give the oil mist a medium to condensate and prevent splashing.
Another downside of the catch can is that it may contain leftover shavings and smelly oils after machining at the factory. I would definitely advise giving the can a thorough wash before installing it in order to remove the metal shavings, as they could wreak havoc in the engine if sucked into the intake system.
The catch can comes with fittings and other hardware that you may need but I would advise getting a proper heat and gasoline-resistant hose, since the one that comes with the can is of poor quality.
Despite the shortcomings, it’s a solid piece of kit that gets the job done, although not very effectively when compared to more serious oil catch cans. If you’re really short on cash, the Vincos universal oil catch can is the best choice you can make for your engine.
- Features a dipstick for an easy way to check the oil level
- 100% washable – no expensive filter changes needed
- Durable full-aluminum construction
- Comes with a breather filter for older engines
- Very affordable
- Quality of the hose isn’t up to par with the rest of the catch can
Oil Catch Can for Turbo Buyers Guide
Why Cheap Oil Catch Can Knockoffs Are Not Worth It
I’m sure you’ve probably seen that there are loads of cheap knockoff oil catch cans on the market too. While it certainly is tempting to get a catch can for half the price, it’s not worth it in most cases.
“You get what you pay for” certainly applies to oil catch cans.
First, knockoff oil catch cans most often come with smaller diameter inlets and outlets. While that doesn’t sound bad, it certainly does not help the PCV system of your engine. A restriction in the PCV system produces back-pressure. The crankcase seals were definitely not designed to hold pressure; therefore, they could start leaking oil.
Second, the pressure relief valves are questionable at best. A trusted brand will not risk its reputation by producing bad quality pressure relief valves, while knockoffs have nothing to lose. If they cheap out on inlet/outlet sizes to save production cost, why shouldn’t they cheap out on pressure relief valves?
Third, and most important: metal shavings after machining in the factory. Quality control is definitely limited when it comes to knockoff oil catch cans. Reputable companies go above and beyond to ensure there are no shavings left after machining, but I’ve personally seen a couple of knockoff oil catch cans that didn’t bother to clean up properly. In a worst-case scenario, you could introduce metal shavings into your intake while trying to catch oil; that could be a disaster.
If you’re already thinking ahead and taking an extra step to protect your engine, is it worth it to potentially risk introducing additional problems?
What to Look for in an Oil Catch Can
While an oil catch can might seem like a very simple component, there are a few things you should consider before buying.
Flow and Performance
First off, you need to think about the driving conditions your engine is subjected too.
If you’re driving a car with an economical gasoline engine, you might get away with getting a cheaper catch can that does not necessarily feature large inlets/outlets for maximum flow. Obviously, it would still catch a lot of the contaminants – it’s just that the cost for extra flow is not always justified.
On the other hand, if you’re driving a high-performance car or a turbo diesel, a more expensive high-flow catch can would definitely make sense. Turbos and boost = more blowby, which means more airflow through the PCV system and more contaminants. A small, cheap catch can would certainly become a restriction to flow and cause backpressure – your oil seals won’t like that!
There are two main ways that oil catch can manufacturers catch oil – baffles and actual filters.
Baffles are cheap to manufacture. They provide a surface for the oil vapor to condense and form drops.
Do they work? Absolutely. Are they effective? Kind-of.
On the other hand, filters are more expensive to manufacture but they are very effective at catching contaminants.
They don’t have to be fancy. Take a look at the Mishimoto – a simple brass filter is cheap and catches a lot of contaminants.
Capacity and Size
You have to know the size of your catch can before you go out and buy it.
Generally, the bigger the capacity the better, but that’s not always possible. We want a bigger capacity so that you won’t need to empty the catch can every week. However, the engine bay on some cars is so tightly packed, you could be struggling to even fit a small catch can.
Oil Catch Can for Turbo FAQ
How Often Should I Drain My Oil Catch Can?
It depends on the type and size of your engine, as well as the operating conditions it’s subjected to. It’s best to measure the oil in the catch can shortly after installing it for the first time. That way, you’ll get a baseline, won’t risk overfilling and will be able to estimate the future drain intervals.
Where Should I Mount My Oil Catch Can?
Ideally, you’d want your catch can to be located wherever there is room to access it easily. Getting the can away from the heat of the engine could be a good idea, but don’t add too much length to the hoses as that could mess with the flow of the PCV system and cause fault codes.
Does an Oil Catch Can Need a Breather?
No. The whole point of a catch can is to keep the PCV system closed, and to not let any oil to escape to outside. A breather will create a vacuum leak, cause fault codes on a PCV system and is illegal in some states.
Breathers are only necessary for old engines that used to dump crankcase fumes onto the ground – if your engine is that old, your car won’t benefit from a catch can.
Does an Oil Catch Can Increase Horsepower?
No. An oil catch can MAINTAINS horsepower. It keeps the intake system and the intake valves clean which keeps the airflow to maximum.
Eddie is the co-founder of CarCareCamp.com, and the site’s primary contributor.
Under his belt, Eddie has a bachelor’s degree in Automotive Electronics Engineering and almost a decade of experience working as a semi-truck technician (specializing in electrics).