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I would like to start a NEW catch can post for all to follow.


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The catch can posts are all over and sometimes hard to follow.  I would like to have all that are interested post their results here and I will as well.  I have pics and mileage along with concerns about the overall amount of oil I'm seeing from my gasser.  Anyhow please post questions, concerns, results, how many miles, how much oil in your catch can, do you like it, do you hate it, etc etc....how about this be the post we can resort to for any and all questions concerning catch cans.  Sound like fun?  Sounds like fun to me....

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I installed a JL (used to be JLT) catch can around 300 miles on my 2022 Custom 2500HD gasser right after I bought it.  I went to have the oil changed at 2500 miles at a dealer in North Carolina and asked the tech to see how much oil was in the catch can.  He said it was around an ounce....good gestimate I assumed.  So 2000 miles later @Pryme asked me to see how much was in my catch can.  I was surprised to say the least. It was 1.2 ozs.  Yesterday 1300 miles later which puts me at 5831 miles I got 24ml out of it which translate to .8 of an ounce.  So I do believe that catch can is doing it's job for sure.  I was a little concerned about the overall amount but there are so many factors involved that it really isn't a conversation really.  Temp, towing, hard running, idling...etc etc....so pretty much all I found out is that what is in your catch can didn't get into your intake and that's good....here are some pics...

20221213_001647.jpg

20230128_132418.jpg

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15 minutes ago, Pryme said:

I should get one of those. 

Amazon...160 bucks.  I'm relieved knowing that's not coking up the back of my intake valves.  Just piece of mind really and hoping for longevity out of it.  At my age, I'm thinking this is my last truck, so why not take great care of it.

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On 1/29/2023 at 9:15 PM, Jettech1 said:

Amazon...160 bucks.  I'm relieved knowing that's not coking up the back of my intake valves.  Just piece of mind really and hoping for longevity out of it.  At my age, I'm thinking this is my last truck, so why not take great care of it.

Did you ever figure out if one is needed on the other side or if a Y fitting of some sort is needed?

 

otherwise would it not only be taking oil from one bank?

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6 minutes ago, Pryme said:

Did you ever figure out if one is needed on the other side or if a Y fitting of some sort is needed?

 

otherwise would it not only be taking oil from one bank?

 

Air is 'drawn' through the motor by manifold vacuum. If the motor has a PCV that acts as a check valve when needed. If it is a orifice based system, yes you could get some back flow and it could be an issue IF ring seal is weak. IF that is the case the catch can is a band-aid on a GSW. Rings need attention.

 

On 1/29/2023 at 8:11 PM, Jettech1 said:

So 2000 miles later @Pryme asked me to see how much was in my catch can.  I was surprised to say the least. It was 1.2 ozs.  Yesterday 1300 miles later which puts me at 5831 miles I got 24ml out of it which translate to .8 of an ounce. 

 

When you have about 3 ounces see  @Black02Silverado for labs on it. See how much is oil, and not fuel or water. This has been done before so I have reason to believe it's not all oil. A good part of it isn't. If it is, then there are other issues. Just say'n. It's worth a look. 

 

On 1/29/2023 at 9:15 PM, Jettech1 said:

Amazon...160 bucks.  I'm relieved knowing that's not coking up the back of my intake valves.  Just piece of mind really and hoping for longevity out of it.  At my age, I'm thinking this is my last truck, so why not take great care of it.

 

@CamGTP motor at 104K without a can. Valve coking isn't a given, it's a possibility.

 

Here's something not well known. The oil you use has a lot to do with the volume of deposits left behind even if some oil is being carried over. Low SAPS oils and those with little to no VII chemistries don't leave much behind. Coke is a misleading term given to these deposits. It would have to get as hot as an autoclave to leave actual coke. Back side of the intake valve never gets that hot. Not even during the hot soak. (in a road going motor) Those deposits are crosslinked polymers added to the oil for various purposes combine with metallic ash. Esters leave fewer deposits as well. Again, just say'n.

 

Most of what is seen in this photo is soot from passive EGR. 

 

CameronsMotor104000Miles.jpg.f662a251ee8a539f16e83175681d19f0.jpg

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I think passive EGR is the main culprit of intake valve deposits in these late model DI engines.  Grumpy Bear is right, modern synthetic oils do not leave many deposits at the temperatures encountered in the intake ports.  

Edited by C/K Man
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12 hours ago, Grumpy Bear said:

 

Air is 'drawn' through the motor by manifold vacuum. If the motor has a PCV that acts as a check valve when needed. If it is a orifice based system, yes you could get some back flow and it could be an issue IF ring seal is weak. IF that is the case the catch can is a band-aid on a GSW. Rings need attention.

 

 

When you have about 3 ounces see  @Black02Silverado for labs on it. See how much is oil, and not fuel or water. This has been done before so I have reason to believe it's not all oil. A good part of it isn't. If it is, then there are other issues. Just say'n. It's worth a look. 

 

 

@CamGTP motor at 104K without a can. Valve coking isn't a given, it's a possibility.

 

Here's something not well known. The oil you use has a lot to do with the volume of deposits left behind even if some oil is being carried over. Low SAPS oils and those with little to no VII chemistries don't leave much behind. Coke is a misleading term given to these deposits. It would have to get as hot as an autoclave to leave actual coke. Back side of the intake valve never gets that hot. Not even during the hot soak. (in a road going motor) Those deposits are crosslinked polymers added to the oil for various purposes combine with metallic ash. Esters leave fewer deposits as well. Again, just say'n.

 

Most of what is seen in this photo is soot from passive EGR. 

 

CameronsMotor104000Miles.jpg.f662a251ee8a539f16e83175681d19f0.jpg

You are absolutely right.  My point was is that I'm glad that oil, regardless of how much, is not going into my intake and possibly coking up the back side of my intake valves.  I agree that coking may not be the best word for it, how about we say burnt deposits like ash.  Now Ford has a huge problem with deposits on their DI engines, I own one and have a catch can on it to help prevent that.  But we are talking about GM engines and what GM uses for oil as compared to what Ford uses and I don't think there's even a comparison.  I did some research on the AC Delco oil they use at the dealership and it comes from Exxon/Mobil.  Of which are well known for great oils.  Having said all of that, I don't think there's any harm using a catch can, actually I think it's a good thing to keep the intake as oil free as possible and to keep that oil off the back side of the intake valves.  I think the best idea is a combo system like my 2021 Ford Escape engine had.  It was DI and port injected.  What a perfect combo in my mind.  Anyhow thanks for your very detailed response, I always enjoy learning, it helps everyone!!

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9 hours ago, Jettech1 said:

I don't think there's any harm using a catch can, actually I think it's a good thing to keep the intake as oil free as possible and to keep that oil off the back side of the intake valves. 

 

No sir, no harm at all. 

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Your'e trapping fuel seasoned with some EGR's carbon and a trace of engine oil. Lower fuels dilution via clean injectors, good coils, plugs, clean air filter, best fuel you can get  and optimize  burn and watch the liquid volume DROP to nil.  

 

Another bandaid that is masking the cause, prefer solving for cause not mask it. Its cheaper too. 

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8 minutes ago, diyer2 said:

Well custom there are damn few perfect engines IMO. So whatever the can catches works for me.

Help me with that logic?  You can't change or check spark plugs, boots or wires and make sure no corrosion on connections, use a better fuel, add Amsoil PI every 4000 miles if you have to use crap fuel, change the air filter, check the OEM coils are not partially misfiring?   You know if the spark isn't correct, things are worn or defective if brand new, and DI injectors are clogged you are just masking all that right?   Knock urself out if so.  If these engines NEEDED catch cans GM would have installed them. Their test engineering was using engines burning clean with clean test fuels. Miles and cycles make all our engines imperfect but buying an aftermarket bandaid BEFORE correcting tune is well, stupid.  

 

Look at the oil analysis on my L3B from purchase to the last analysis and note fuels dilution is LOW and engine is clean.  Basic stuff to make that happen but I test it to be sure its clean. 

 

I prefer a fix best you can before I bandaid things. 

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First I have never bandaided anything. I just don't get as technical but have had good results of longevity with no mechanical failures for years. 

 

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