CEL for Spark Knock AND P0300 fix

[Allen_NC]

Not sure this will work for EVERY Gladiator out there on the road, but I did a thing.

Some of you awesome folks made it known about the new TSB-09-012-22 for spark knock/engine symptoms... For any who havent seen it, it involves pulling the heads, cleaning the piston head, and the heads to resolve a spark knock condition being caused by "Oil intrusion through the PCV system."

This is affecting: 2018-2022 JL, 2020-2022 Gladiator, and 2018-2022 Grand Cherokee

I pulled my PCV line and it almost dripped oil... and needless to say was not happy. Enter one of my other good friends who does some light tuning, and is an engineer. We got to talking, and it seems to make sense (from fairly non professionals) that
A. Oil vapor coming back through the intake WILL affect the AFR in each cylinder potentially at a different amount, thus causing the computer to think there is a misfire happening since each cylinder is making different pressures.
B. Dealer said that in some cases there is enough oil that it can actually "COKE" to the pistons and just become working carbon. With enough buildup and todays tight tolerances, that can effectively modify the compression ratio (unevenly) in each cylinder, and throw more codes.

So how to fix this??? I am only at 6,500 miles on mine, and personally I AM NOT ready to do open heart surgery. If it had 75-80k on it, ok.. some deep cleaning might not be so bad, but NOT under 10k.

I called a couple of buddies who do some high performance tuning (Nameless Performance, and English Racing) and asked what they would do. Unanimous answer was catch can,,, just drop a catch can in it, and see what it does.

I ordered mine from Mishimoto (through Amazon), it cost $225, took 30 minutes to install and it has changed everything. It has never idled as smooth, there is ZERO knock, or pinging on moderate acceleration or spirited downshifts, the PCV line feeding into the intake is now dry, and so far, it appears to be working a treat.

Sorry for the long post, but I know there are enough of us here, who arent in the high mileage club yet, and I would also assume, that nobody wants the top end of their motor torn apart by their local and amazing service departments. Will gladly elaborate on more, if anyone wants to talk about it.

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[mert34]

English racing, have not done much with them since i had a evo.

catch can will catch it yes but why is there so much in then to start with?

with that said every vehicle i have owned has has one installed. people will argue both directions on if one is really needed.

let us know how ends up in the can after a little bit of driving.

 

[Allen_NC]

English racing, have not done much with them since i had a evo.

catch can will catch it yes but why is there so much in then to start with?

with that said every vehicle i have owned has has one installed. people will argue both directions on if one is really needed.

let us know how ends up in the can after a little bit of driving.

not sure why in the first place, but it is a thing. They seem to have a LOT of vacuum at idle, and mine threw the codes while navigating a parking lot. Never while under actual driving load. They have revised the PCV itself (new part number), but of course they’re back ordered.

 

[ShadowsPapa]

Odd I've never been able to find such a TSB - I assume you have a real copy?
I haven't seen a TSB related to knock that involves anything other than PCM flash.
For DI engines it's a bigger issue, for multi-port injection, not so much.
For an engine to throw that much into a cylinder you'd notice a drop in the oil level in the crankcase so be careful of what people claim to be catching with a catch can. Most of the time it's 90% condensation.
There really isn't a wide-spread issue with these and TRUE, real, verified spark knock.
But I'd not be surprised for a revised PCV - they made a big change to it after 2015 as it was.

 

[Allen_NC]

I mean, i put the TSB number in the original post.

**EDIT** I had to shrink the pic here, it was too large. I got this at my local Jeep store.

 

[Idlethunder]

Following

 

[Allen_NC]

Spending WAAYY more time "talking" with Mopar... Mopar says, contact the dealer, and the Dealer says Contact Mopar for more info. Nobody seems to be willing to release an official copy of the TSB. Im glad I at least got to take a pic of it last time I was in there.

 

[Hootbro]

Oh boy. Letting a dealership dig that deep into an engine is going to create more problems in my opinion.

I really like to see the full service instruction because if it is just a cleaning, that is a band aid .

 

[Allen_NC]

Oh boy. Letting a dealership dig that deep into an engine is going to create more problems in my opinion.

I really like to see the full service instruction because if it is just a cleaning, that is a band aid .

Correct about the band aid. I have <7000 on my Jeep, and after speaking with the cranky, angry, older guy who has worked on Jeeps for like 40 years... I decided to go the Catch Can route, and a little dose of sea foam. Seems to be doing great. I'll update when I actually have to empty the can.

 

[JTenn]

Not sure this will work for EVERY Gladiator out there on the road, but I did a thing.

Some of you awesome folks made it known about the new TSB-09-012-22 for spark knock/engine symptoms... For any who havent seen it, it involves pulling the heads, cleaning the piston head, and the heads to resolve a spark knock condition being caused by "Oil intrusion through the PCV system."

This is affecting: 2018-2022 JL, 2020-2022 Gladiator, and 2018-2022 Grand Cherokee

I pulled my PCV line and it almost dripped oil... and needless to say was not happy. Enter one of my other good friends who does some light tuning, and is an engineer. We got to talking, and it seems to make sense (from fairly non professionals) that
A. Oil vapor coming back through the intake WILL affect the AFR in each cylinder potentially at a different amount, thus causing the computer to think there is a misfire happening since each cylinder is making different pressures.
B. Dealer said that in some cases there is enough oil that it can actually "COKE" to the pistons and just become working carbon. With enough buildup and todays tight tolerances, that can effectively modify the compression ratio (unevenly) in each cylinder, and throw more codes.

So how to fix this??? I am only at 6,500 miles on mine, and personally I AM NOT ready to do open heart surgery. If it had 75-80k on it, ok.. some deep cleaning might not be so bad, but NOT under 10k.

I called a couple of buddies who do some high performance tuning (Nameless Performance, and English Racing) and asked what they would do. Unanimous answer was catch can,,, just drop a catch can in it, and see what it does.

I ordered mine from Mishimoto (through Amazon), it cost $225, took 30 minutes to install and it has changed everything. It has never idled as smooth, there is ZERO knock, or pinging on moderate acceleration or spirited downshifts, the PCV line feeding into the intake is now dry, and so far, it appears to be working a treat.

Sorry for the long post, but I know there are enough of us here, who arent in the high mileage club yet, and I would also assume, that nobody wants the top end of their motor torn apart by their local and amazing service departments. Will gladly elaborate on more, if anyone wants to talk about it.

Can you post a link to the Amazon item? I'm interested in doing more research on this.

 

[Allen_NC]

Can you post a link to the Amazon item? I'm interested in doing more research on this.

https://www.amazon.com/dp/B07Q6H8HB3?psc=1&ref=ppx_yo2ov_dt_b_product_details

 

[JTenn]

https://www.amazon.com/dp/B07Q6H8HB3?psc=1&ref=ppx_yo2ov_dt_b_product_details

Thanks!!

 

[ShadowsPapa]

I mean, i put the TSB number in the original post.

**EDIT** I had to shrink the pic here, it was too large. I got this at my local Jeep store.

Uh, I know you did. I could sarcastically say "how do you believe I searched my folder of TSB files and web-based resources" but won't LOL

not sure why in the first place, but it is a thing. They seem to have a LOT of vacuum at idle, and mine threw the codes while navigating a parking lot. Never while under actual driving load. They have revised the PCV itself (new part number), but of course they’re back ordered.

These have no more vacuum than most others at idle.
Do you know how PCV valves are typically designed? They close under high vacuum situations. Those that actually DO use valves (some makes/models/engines use a metered orifice) it's a two way valve. It closes under pressure and is only full open at moderate vacuum. under high vacuum they close against spring pressure. There are multiple types and calibrations based on engine design, pumping efficiency and more.
Been at this for a long time. Well aware of how PCV works, typical intake vacuum situations, and how oil impacts combustion.
They have an issue with the calibration, even baffling of the PCV system if there is excess oil getting into the combustion chambers. Luckily, very very few of these actually have true ping or knock.

I pulled my PCV line and it almost dripped oil... and needless to say was not happy. Enter one of my other good friends who does some light tuning, and is an engineer. We got to talking, and it seems to make sense (from fairly non professionals) that

B. Dealer said that in some cases there is enough oil that it can actually "COKE" to the pistons and just become working carbon. With enough buildup and todays tight tolerances, that can effectively modify the compression ratio (unevenly) in each cylinder, and throw more codes.

Oh, the engineer thing - is he an engine design engineer?
What's on the pistons is carbon - it's unburned hydrocarbons from the oil (and a certain amount from gasoline itself). The carbon from oil can be quite hard and build up to the point of the carbon itself causing a knocking as it hits the cylinder head at TDC, further compressing the carbon. It can raise the compression ratio, and it can get hot and GLOW, causing pre-ignition.
The higher compression and extra heat can cause detonation (different from pre-ignition)
Pre-ignition can lead to detonation but they are actually two different things people seem to get tangled up over.

A. Oil vapor coming back through the intake WILL affect the AFR in each cylinder potentially at a different amount, thus causing the computer to think there is a misfire happening since each cylinder is making different pressures.

Not quite. It doesn't measure pressure, it measures the oxygen remaining in the exhaust gases. It will try to adjust the injector cycle to compensate based on the O2 sensor voltages. Then a misfire takes place.

You really still need to get the latest correct PCV valve installed. Your catch can is a bandaid.
The correct PCV ensures you have the correct crankcase vacuum and cut the oil leaving the crankcase. The catch can shouldn't even be needed if the PCV system is corrected. A catch can doesn't undo the carbon already formed in the combustion chamber.

Any onlookers need to get a top quality catch can, not a cheapie. This has been covered ad nauseum in other threads. They need to be somewhat insulated and installed in such a place and way that you don't end up catching more water than oil.
In a catch can, cheap is not the way to go.

Also - the choice of oil can impact all of this - including pinging. New specs/standards for oil address ping of LSPI.

Go catch can if you desire, but ignoring the fact there's a PCV correction isn't doing anything any favors.

 

[ShadowsPapa]

Oh boy. Letting a dealership dig that deep into an engine is going to create more problems in my opinion.

I really like to see the full service instruction because if it is just a cleaning, that is a band aid .

Agreed. If there's an issue with the PCV calibration, or even baffling in the engine, that should be addressed.
A revised PCV should take care of things.
In the past, using an incorrect PCV valve caused all sorts of trouble. They are far from universal. They are calibrated. When we stocked PCV valves in the past, there was a whole cabinet with a couple of dozen different part numbers. Wrong PCV and you have oil consumption, lean conditions and so on.

There's something missing as far as how this all came about to begin with on a low miles engine - and the instances of such a build-up is really quite low, so a TSB on this? Hundreds of thousands of these 3.6s are out there, many with some pretty high miles, and pinging isn't a common theme among them. Neither is carbon build-up in the combustion chamber.
Root cause investigation needed as well as the full TSB to see what's REALLY going on.
IMO, Not enough valid/good/reliable info here so far. (what "dealer" said isn't technically accurate, and you can't go by what most say - they read computer screens and don't know the technical aspects of operation or combustion)

 

[Allen_NC]

Uh, I know you did. I could sarcastically say "how do you believe I searched my folder of TSB files and web-based resources" but won't LOL


These have no more vacuum than most others at idle.
Do you know how PCV valves are typically designed? They close under high vacuum situations. Those that actually DO use valves (some makes/models/engines use a metered orifice) it's a two way valve. It closes under pressure and is only full open at moderate vacuum. under high vacuum they close against spring pressure. There are multiple types and calibrations based on engine design, pumping efficiency and more.
Been at this for a long time. Well aware of how PCV works, typical intake vacuum situations, and how oil impacts combustion.
They have an issue with the calibration, even baffling of the PCV system if there is excess oil getting into the combustion chambers. Luckily, very very few of these actually have true ping or knock.



Oh, the engineer thing - is he an engine design engineer?
What's on the pistons is carbon - it's unburned hydrocarbons from the oil (and a certain amount from gasoline itself). The carbon from oil can be quite hard and build up to the point of the carbon itself causing a knocking as it hits the cylinder head at TDC, further compressing the carbon. It can raise the compression ratio, and it can get hot and GLOW, causing pre-ignition.
The higher compression and extra heat can cause detonation (different from pre-ignition)
Pre-ignition can lead to detonation but they are actually two different things people seem to get tangled up over.


Not quite. It doesn't measure pressure, it measures the oxygen remaining in the exhaust gases. It will try to adjust the injector cycle to compensate based on the O2 sensor voltages. Then a misfire takes place.

You really still need to get the latest correct PCV valve installed. Your catch can is a bandaid.
The correct PCV ensures you have the correct crankcase vacuum and cut the oil leaving the crankcase. The catch can shouldn't even be needed if the PCV system is corrected. A catch can doesn't undo the carbon already formed in the combustion chamber.

Any onlookers need to get a top quality catch can, not a cheapie. This has been covered ad nauseum in other threads. They need to be somewhat insulated and installed in such a place and way that you don't end up catching more water than oil.
In a catch can, cheap is not the way to go.

Also - the choice of oil can impact all of this - including pinging. New specs/standards for oil address ping of LSPI.

Go catch can if you desire, but ignoring the fact there's a PCV correction isn't doing anything any favors.

True and correct on all of that. What's wrong with the PCV?? Who knows, it's Jeep... probably something simple and stupidly overlooked during design.

According to my local Jeep shop, there is a new part number for the PCV, but theyre already back ordered until like January or something.

Im not thinking its KNOCK, from excess buildup, but under gentle(ish) passing acceleration she would ping/knock up a blue streak.

Reference the engineers, one with a masters in mechanical engineering, and the other a PHD. English Racing does a lot of builds and tuning as well, ergo, I feel my resource is fairly sound. Are they 'engine design," perhaps not... but they both build high performance, high horsepower engines, rally cars, severely boosted applications and more. Tuning is usually on a razors edge from either setting a record, or blowing up.

While you are also correct about how these new fangled ECM's and ECU's meter, monitor, and correct everything, the computer knows it dosed X amount of fuel, and is tuned for X amount of air (at a given temp and altitude). It then expects certain readings down the pipe. Now its metering the fuel, and its getting the air, but the oil vapor or slow burn (pre coking) of the oil can change that chemistry, it will try to advance or retard the timing, but its not enough and sounded like marbles in a Folgers can.

Moral of all this, is that Stellantis has a solution, which is to pull the heads, let Jeep Tech Jimmy clean them (wire brush and solvent? walnut blaster? flathead screwdriver and a few monsters), and then clean the piston heads as well. Now if I still had my TJ, and it had lots of miles on it already, id probably not care in the slightest. For those of us who have new vehicles, with low miles, im personally not a fan of opening her up for surgery just yet. The band aid seems to have fixed the issue right now, and for that I am thankful.

The affected models are many, and in every market. JL and Grand Cherokees were I think 2018-present, and ALL of the Gladiators.

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