Talk to me about oil catch cans and intake valve deposits

[twX]

Does this mean the oil is from the valve stem seals?

No, it's normally from the oil that's in the blowby gas that flows through the PCV system. The blowby gas contains a mist of very small oil droplets. There will be some vaporized oil in the blowby gas as well, but it doesn't seem to contribute much to valve deposits.

Leaky valve stem seals will of course also contribute to valve deposits. So will burned oil from the EGR system.

 

[SC Maintenance]

Catch can's are as old as the hills. If you want to run one - feel free. Most of what you will find in it will be condensation - but it won't hurt anything. Beyond that its the same as the thick / thin debate.

FWIW if I had DI only and it was easy to install one on that particular engine, I likely would.

 

[Al]

Probably a waste of time.

 

[repairman54]

I put a can on my '16 3.6 Equinox. Always get 3 oz. of oil in it at every 5k change. Summer just oil only, winter add in condensation.
At 110k miles now, bought it new, can went on at 50k miles. Newer 3.6 have an oil separator from the factory, my '20 Traverse has it, not the 'nox. Here's a picture of intakes when I did the 100k plug change. Good enough for me not to dive into cleaning them.

 

[Rust_Belt_Pete]

If you have no port injection and are mechanically inclined I would get meth injection.

 

[dfarr67]

After seeing what I dump out of the can from the DI Honda- all my vehicles sport cans. Can't hurt and may save $$ down the road for any cleaning. Quality can is a must.

 

[KevinMalone]

There are some risks with oil catch cans. The hoses have to be sized properly with appropriate lengths, and the can shouldn't have any restrictive filtering that increases crankcase pressure. I've seen some catch can hoses freeze up with water in the winter too. If there is no proven benefit, I don't think I would bother. It's another thing to service too.

This video demonstrates how the filter on some catch are too restrictive:

 

[FoxProTwisty]

I put one on my port injection truck maybe 75k miles ago. It seems to work as it should, esp in the winter. But when I took the intake off to change the gaskets recently, oil still poured out of it when I stood it on end.

 

[rijndael]

But when I took the intake off to change the gaskets recently, oil still poured out of it when I stood it on end.

What are the chances that oil was there from before the can install?

 

[FoxProTwisty]

What are the chances that oil was there from before the can install?

For sure some of it was. My point is these cans only catch so much of the mist and shouldn't take the place of keeping the engine tip top.

 

[wtd]

For sure some of it was. My point is these cans only catch so much of the mist and shouldn't take the place of keeping the engine tip top.

The other thing with catch cans is that they are not all built the same inside and some are more effective than others. I've had a catch can on my 2014 Mustang GT since it was new and actually did some testing on various models of cans putting two cans in series to each other and then switching them around to see how much the second can would catch that the first can did not. I chose the one that let the least amount of oil through.

We installed a can on my fiancé's 2007 Mustang GT when it had around 10,000 miles on it because it was blowing out blue smoke on a cold startup. Some people on a Mustang forum suggested it and it worked for her car. No more smoke on startup. Her car was pulling a ton of liquid oil into the intake. When I pulled the hose off for the first time, it was dripping with oil. Now with the catch can, there is only a film of oil at the intake hose.

 

[burbguy82]

The formation of deposits and nasties that RP is supposed to remove, may not be mitigated by the same oil. I do not know either way, but it would make sense that the oil would help with cleaning and stopping deposits to begin with.

But I think what you are getting at is the back side of the intake valves on a DI.?????

A catch can has got to have an effect on the coking of the intake valves......the trick is, finding all the PCV hoses and making them go through the can.

 

[Sierra048]

In my mind, a CC is going to capture oil that will not have to fly through your intake valve ports. The question is, how much better will that prevent IVDs for your specific situation, vs leaving it stock? Too many variables to measure.

I had a J&L catch can kit installed on my 2022 Nissan Frontier for about 40K miles. It required regular maintenance in cold weather, like a draining every 2 weeks or risk filling the can to the top. It would fill with condensed moisture and some oil. In the warmer months I would get ~2-3 ounces of what looked/smelled like gassy used engine oil w/ no moisture per 5K oil change.

I removed the CC when I gave the truck to my daughter who lives 750miles away because of the maintenance required when having one in place.

I installed a J&L catch can on our 2024 Frontier in February. I just checked it for the first time with 650 miles on the install and got about 1 1/2 ounces oily residue. Truck had 4955 miles when installed.

 

[JTK]

I installed a J&L catch can on our 2024 Frontier in February. I just checked it for the first time with 650 miles on the install and got about 1 1/2 ounces oily residue. Truck had 4955 miles when installed.

I would easily get 2x that amount in that mileage with the winter temps I get. So much so, that I bought the can extension from J&L that doubled the stock capacity. This is with all highway use as well. J&L makes a nice product and the install is so simple, clean and easy to undo on the 2022+ Frontier, that's most of the reason why I tried one.

 

[Sierra048]

I would easily get 2x that amount in that mileage with the winter temps I get. So much so, that I bought the can extension from J&L that doubled the stock capacity. This is with all highway use as well. J&L makes a nice product and the install is so simple, clean and easy to undo on the 2022+ Frontier, that's most of the reason why I tried one.

Agreed. That's the reason I went with J&L as well. Although we've had a colder than normal winter, we don't drive as much as we used to.

 

[dfarr67]

I put one on my port injection truck maybe 75k miles ago. It seems to work as it should, esp in the winter. But when I took the intake off to change the gaskets recently, oil still poured out of it when I stood it on end.

Sounds like blowby and/or pcv issues. Same on my trucks tpi- ss wool in the valve cover vent, custom adjustable pcv and a catch can band aided the issue.

 

[Al]

No proof and a lot of doubt that it does anything.

 

[BobsArmory]

Catch cans can damage your engine especially if you live in areas that are below freezing.

 

[JimPghPA]

I have never scoped the valves of my Honda 2.4 L na engine. That said, everything else I'm doing re intake valve mitigation is a best as I could shot in the dark.

I run PUP and change it asap after the mm drops to 20 %. PUP is a very now NOAC oil.

Honda engines and most others are designed to cause the valves to rotate about the stem. Honda also includes that during certain conditions, when the intake valves are open, a brief spray from the injector hits the back of the open valve to try to wash it clean.

I put about 3/4 of a bottle of RedLine SI -1 fuel system cleaner in the fuel tank at the station just before a fill about every 10 K miles and then run that tank very low before refilling. AND, I also use a 100 mL translucent white plastic graduated cylinder to add 4.45 mL per gallon (maintance dose ) just before all fill ups ( I use the trip B to track miles on the tank and mpg to calculate how many gallons it will take, and multiply that by 4.45 mL ), except of course the times I heavy dose it with 3/4 a bottle. ( You can buy those graduated cylinders from McMaster-Carr online or by phone.)

So, if fuel does occasionally get sprayed on the back of those valves it has some cleaner in it to help it clean.

And this also keeps my injectors very clean.

 

[KrisZ]

Catch cans are good at showing the gunk and terrifying people. The effect is similar to the wear scar test. Both are designed to take advantage of the lizard part of the brain. The material caught, while very scary looking in the can, is in harmless vapor form and the amount of it is minuscule when compared to the volume of air ingested each second by the engine.

DI has been around long enough to show the effects of these catch cans, yet most "evidence" revolves around showing what they "caught" instead of showing the intake valves. It's a mostly a feel good gadget, that in some cases may help and in some, it may negatively impact the existing OEM oil separation method. People installing them simply hope it will help.