Direct Injection carbon & other 2.0T issues

[hiimmike]

Hello! I recently ordered a '22 with the 2.0T. I'm reading about direct injection having a common problem of carbon build up on the top of the valves. Has anyone had a problem with this yet and at what mileage? Anything that you're doing to mitigate this? I understand you should use full synthetic and maybe there are some DI maintenance kits. This is the most expensive vehicle I've ever purchased so I want to make sure I take good care of it.

Are there any other issues that are common that I should be aware of and start researching now as I wait until February for my new Jeep to come in?

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[JasonInDLH]

An oil catch can should keep things clean for you in that respect. Can install a bundle of steel wool inside the catch can as well. This will help to keep blow-by crud out of your intake thereby keeping carbon buildup a non-issue for you.

Also, I’m a big proponent of occasionally redlining it throughout the life of the vehicle as this helps keep the area clean. “I promise officer…I was just doing periodical engine maintenance.”

 

[hiimmike]

An oil catch can should keep things clean for you in that respect. Can install a bundle of steel wool inside the catch can as well. This will help to keep blow-by crud out of your intake thereby keeping carbon buildup a non-issue for you.

Also, I’m a big proponent of occasionally redlining it throughout the life of the vehicle as this helps keep the area clean. “I promise officer…I was just doing periodical engine maintenance.”

You definitely lost me here. I'll have to look up an oil catch can.

 

[four low]

Use the oil specified in the owners manual for the 2.0T.
It is specially formulated for DI engines, you don't need a " catch can " ,but judge for yourself by reading the discussions on this.

 

[cs2k]

I also considered purchasing a catch can for my 2.0. However, after reading this thread, it seems like the 2.0 is an exceptionally clean engine and nobody who bought the catch can is really catching anything.

 

[JasonInDLH]

@hiimmike A Catch Can is a simple Can connected to the PCV and catches oil, unburnt fuel, and I believe even water (if the conditions are correct, such as very short trips which may cause condensation in the right temperatures).

And it certainly is helpful in direct injection engines. Here’s how: the fuel (which is a very good cleaner) is sprayed directly into the combustion chamber, but misses the intake valves and thereby doesn’t clean them. The result is carbon buildup on your intake valves. Add the catch can to the equation and you’ll keep your intake valves clean. The result is no loss of power over time when it comes to these parts mentioned.

Just remember to empty the can at regular intervals. For instance…UPR Catch Can claims that it needs to be emptied every 500 miles due to the efficiency of their can. My JLT Catch Can on my Yukon can be drained less often.

The Can is very easy to install and anyone can do it.

Here’s a good article:
https://www.lsxmag.com/tech-stories/engine/catch-can-why-direct-injection-makes-them-a-must/

And I like this YouTube video:

 

[hiimmike]

Thanks all! I’m just going through the link that cs2k posted. This seems like a lot of extra maintenance, every 500 miles? Sheesh. Still making my way through it, on page 6. Read all the Mishimoto posts during the R&D, interesting and learning new things!

 

[JasonInDLH]

Thanks all! I’m just going through the link that cs2k posted. This seems like a lot of extra maintenance, every 500 miles? Sheesh. Still making my way through it, on page 6. Read all the Mishimoto posts during the R&D, interesting and learning new things!

Yeah…I personally don’t want to drain the can every 500 miles, so will probably be installing something cheap from Amazon and fill with steel wool.

 

[Sargeoverland]

I’ve used catch cans on all of my previous turbo vehicles and now Jeep. For the Jeep though it only has 10k on it knowing the catch can is there is a piece of mind. How much it helps might be little but it is helping. All turbo di motors should have one

 

[hiimmike]

https://doyouevenboost.com/blogs/ne...n-oil-catch-can-work-and-why-is-it-beneficial

This was very helpful and I understand what blow-by is and why we need a PCV valve and why we need a catch can. This is interesting stuff and it’s fun learning about how my vehicle will operate.

 

[jjvincent]

I see lots of DI motors from various manufacturers. In the end, people that are lazy with oil changes end up getting misfire codes due to too much carbon buildup on the backsides of the valves. I do also see that some manufacturers that have 10K oil changes tent to have the misfire codes more often. 5K oil changes seems to work better at keeping this problem from happening. I do get my real world experience at working on various cars with many reaching 400K on the motors and they are DI (some turbo and some not) where the motor has never been opened up and no carbon buildup. Those are just regularly maintained.

People that go off the deep end with catch cans are only using the failures for their justification. Not the overwhelming successes that do not have a catch can. The intranets seem to fixate on the few failures and thus need an extreme solution.

If you want to run a catch can, then take and put a fitting on the bottom and then a fitting on the oil pan. Run a hose between the two and then you never need to drain it. That's what we do in racing as we run "loose" engines.

 

[cs2k]

I do also see that some manufacturers that have 10K oil changes tent to have the misfire codes more often. 5K oil changes seems to work better at keeping this problem from happening. I do get my real world experience at working on various cars with many reaching 400K on the motors and they are DI (some turbo and some not) where the motor has never been opened up and no carbon buildup. Those are just regularly maintained.

You seem extremely knowledgable and experienced on the subject. Could you help me understand how oil change intervals and carbon buildup affect each other in DI engines?

I was under the impression that carbon buildup on the DI engine was due to the dirty PCV/CCV vented vapors condensing on the back of valves. On a normal engine, the detergent action of air-fuel mixture rushing past the valves mitigates this problem. On DI engines, the absence of this action means that the buildup is free to accumulate over time.

Does not changing oil create more "sticky" PCV/CCV vapors? or does misfires affect the PCV/CCV venting action to some degree?

 

[zrickety]

Hello! I recently ordered a '22 with the 2.0T. I'm reading about direct injection having a common problem of carbon build up on the top of the valves. Has anyone had a problem with this yet and at what mileage? Anything that you're doing to mitigate this? I understand you should use full synthetic and maybe there are some DI maintenance kits. This is the most expensive vehicle I've ever purchased so I want to make sure I take good care of it.

Are there any other issues that are common that I should be aware of and start researching now as I wait until February for my new Jeep to come in?

Catch cans do not mitigate the problem, but people feel like they are doing something.
The truth is the intake valves never see the gas detergents, so it's just a matter of time. The VW/Audi/BMW guys burn off carbon by running 3000+ rpm for 30 minutes...hard driving 'Italian tune up.' The other method involves removing the intake manifold and walnut blasting.
The buildup is gradual, so most don't notice until mpg drops off or misfires happen. I haven't seen it documented here, but I would love to see pics of some high mileage intake valves.

 

[hiimmike]

Great conversations and exactly what I was looking for to learn about it. Thanks for all the contributions and helping me understand these things!

 

[jjvincent]

You seem extremely knowledgable and experienced on the subject. Could you help me understand how oil change intervals and carbon buildup affect each other in DI engines?

I was under the impression that carbon buildup on the DI engine was due to the dirty PCV/CCV vented vapors condensing on the back of valves. On a normal engine, the detergent action of air-fuel mixture rushing past the valves mitigates this problem. On DI engines, the absence of this action means that the buildup is free to accumulate over time.

Does not changing oil create more "sticky" PCV/CCV vapors? or does misfires affect the PCV/CCV venting action to some degree?

Case in point, look inside of an engine that has frequent oil changes vs ones that do not. Why does all of that sludge cake up inside the engine with ones with extended oil changes? Honestly, I do not know the exact answer but on the other hand what I see with thousands of cars I see a year, you see a trend. Trend is, extended oil change intervals results in more cakes up internals and the backside of valves. You also see this with cam position solenoids. They get gunked up and throw a non correlation for the cam timing. Pretty much, when you request 5 degrees advance, the cam will not get there fast enough or at all.

As for non DI motors, gunked up valves is nothing new. Back in the day it was the same problem no matter what fuel you ran (even with CIS fuel injection which constantly sprayed fuel on the backside of the intake valves). The problem back in the day was cold running issues as ECU's and fuel injection was not to the point of forcing the engine to run and then logging misfires. Back then they would either backfire up through the intake or run so lean they would just stall. So, you had to start them up and let them warm up for 10 minutes. I know that most German companies literally changed out temp sensors to just delay going to closed loop, to patch the problem.

So, old oil vapor is hitting the backside of the intake valves. It sticks and builds up. Same for the oil vapor that coats the inside of the engine internals. After that, engines that get more frequent oil changes, the engines look clean inside and they don't have gunked up intake valves. What I find on the intranets is that people usually do not tell you, "I go 10-15K on oil changes and now my DI motor is misfiring when cold and it throws the check engine light?" Instead you hear, "I got a CEL and it shows a misfire." Just like people that come in with 4 bent wheels yet tell you they never hit anything and do not understand why their car is out of alignment. Must be a problem with the manufacturer.

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