Repair Geek on catch cans

[Roscoe_t]

I like the way this guy presents his tests. Here he looks at the efficacy of catch cans.

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[2021Ranger]

So anyone here have there fluid in the catch can freeze up?

 

[Racket]

My UPR has a second vacuum line attached to the intake ahead of the turbo. According to this video that helps to reduce crankcase pressure. He suggests that improves power but those of us on this forum who use the vented oil cap complain of lowered gas mileage. I had my catch can on around 500 miles so I don't have a baseline.

 

[TJC]

I have had my UPR catch can on for 18K miles. Currently at 21.6K miles Traveling I get ~26-27mpg. But it depends a great deal on terrain. From Central NC to the Low Country of SC coast there is a drop of 450'. I get better mileage going then I do coming back. Probably 1.5-2mpg difference. Went 675 miles to Upstate NY 75 miles north of Syracuse and avg 26mpg. That on I-81 through those 2500' hills, up and down...

In town 23-24mpg. I have both vacuum lines as well.

I do not have the vented oil cap.

 

[LawnMM]

I have the vented cap, saw no difference in mileage. Saw some when I put our RTT on the rack though!

 

[Roscoe_t]

The point the repair geek made that stuck with me is that the catch can does nothing whenever the turbo is producing positive pressure in the intake -- or, at least positive pressure that exceeds the pressure in the crankcase. I'm in a rural area and drive mostly at highway speeds, so I think a catch can would be less effective for me than for someone who tools around town on short trips.

This guy also has an interesting approach to cleaning intake valve deposits using zip ties.

 

[Rp930]

So far no one has demonstrated the need for a catch can on the Ranger.

A vented oil cap on a closed system is a terrible idea and introduces false air which in turn will cause the system to add more fuel.

 

[TJC]

The point the repair geek made that stuck with me is that the catch can does nothing whenever the turbo is producing positive pressure in the intake -- or, at least positive pressure that exceeds the pressure in the crankcase. I'm in a rural area and drive mostly at highway speeds, so I think a catch can would be less effective for me than for someone who tools around town on short trips.

This guy also has an interesting approach to cleaning intake valve deposits using zip ties.

That point is true for a single source vacuum systems. It is not true for dual source vacuum systems such as UPR dual source catch can.

UPR uses dual vacuum sources, one source just like our fellow mentions, the other on the intake track of the turbo. Check valves automatically open/close sealing off the source during boost / non boost conditions.

Non boost conditions seals off the boosted source (after the air filter and just before the turbo),

Boost conditions seal off the NA vacuum source (after the turbo at the intake manifold).

The short of it is that the UPR can is functioning the vast majority, if not all of the time.

 

[shovelhd]

My 2 cents on catch cans coming from the VAG world. They make an awful lot of sense in high-hp "street legal" motors, i.e. Stage 3+. Big turbo, downpipe, exhaust, etc. Most factory PCV systems can't keep up with the increased crankcase pressures. They save overloading the intake with excessive oily blowby crap. For anything less than that, they're a showpiece. If you're concerned about GDI carbon buildup, they are of minimal help with stock or Stage 1 (Ford Performance, Livernois/Unleashed/5Star OTS tunes for stock turbos) tunes. It's better to inspect via borescope, and either clean via walnut blast (requires removing the intake and a special port adapter for your engine) or chemical. BG has a system, but I never used it. What I did use every other oil change (every 10K miles) was CRC GDI intake cleaner. I used the MAP sensor port, plugged with a rubber stopper and a long hose, to inject the cleaner while the engine is running. It's not as good as a walnut blast, but you could see the difference with the scope, and you could feel it in the throttle response.

 

[twk]

So anyone here have there fluid in the catch can freeze up?

I have a J&L catch can on my mustang GT. This came up at work one day, so we checked several times when at work, evenings (I worked 4-midnight), car was outside, and the temps were freezing. It was never frozen up. Not even close. Barely frosty inside. Now, the water in the bottom of the can was frozen, but never the air passages. We checked with a can of compressed air.

May I ramble a moment? Hahaha, I will anyway.

I bought a J&L catch can for my '09 V6 Mustang in 2010. I have no idea what I paid. It worked, that is, it had oil in the can after 4 or 5 tanks of gas. A couple of ounces I would guess. I never measured it.

Since the V6 was catching oil, I bought one for my '17 Mustang GT in 2018 to compare. I don't recall the price but it was no where near $160. I think it was just over $100. At that time, the competition was close to the same price I had paid.

I empty the can after 4 or 5 fill ups, and I tend to fill up when I get to a quarter tank or so. There is usually about 3/8" (a couple of ounces) in the can like my V6 'stange. At least it's catching SOMEthing. I guess I'll leave it on.

I'll never get one for my Ranger. They are a PITA to remember to empty, and I can spend the money on something useful, like... Beer. For me, this was an experiment, particularly on my GT. I wondered if the GT would generate more or less oil in the can. It seems my two 'stangs are about the same.

 

[diesel924]

I like the way this guy presents his tests. Here he looks at the efficacy of catch cans.

The rule of thumb for how much crank case pressure is acceptable is 2" of water column which equals .07 PSI. He used 10 PSI through his paint gun set up. That's 10 times the pressure that's normal.

 

[dozxab]

Agree that it doesn't work at boost but 95% of my driving is under vacuum. That fact that it keeps oil and water off the intake valves is a bonus. I empty mine every 2K or so and it has never been more than 10% full, so sloshing isn't an issue. It may not be a perfect solution but I feel it is at least helpful. IMO, he set out to prove they don't help. If that is the premise, then tests can be tailored to that end.

 

[Stevedbvik1]

I have one on the pcv side and the Ford Performance one on the other side. Both catch stuff, primarily in cold weather. Never close to full at anytime that I’ve checked. But what it’s catching isn’t collecting on my valves or turbo compressor wheel so that’s a plus for me

 

[Ninong]

I run a dual can Mountune system that has removable and cleanable filters. I empty them every oil change and clean the filters.
I also monitor my manifold vacuum/pressure with an after market gauge. Cruising at 40mph I am typically at 20% throttle, and have a negative manifold pressure, so even at highway speeds the cans are working.
My experience working in an engine shop tells me that even naturally aspirated engines collect carbon on the back of the intake valves, and that regular oil changes do a lot for keeping carbon deposits down.
IMHO the cans aren't a cure all, but for direct injection probably offer some level of help in reducing carbon deposits.

 

[theprinceofsnj]

I have one. My mechanic empty's it every oil change. He did have a hell of a time installing it. I got it to reduce Carbon buildup on the intake valves.

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