Engine knock-brought it to the dealer today

[Stan H]

Burned valve will be very rare in these.
The causes have been all but eliminated. It used to be not uncommon in the days before positive valve seals, better guide tolerances (tighter guides) and greater oil consumption that was common in engines of the past.

You can also often tell by exhaust sound, and on a slowly idling engine, by using a dollar bill, or tissue, at the end of the tail pipe. A faulty exhaust valve - either by burning or by being held up by carbon, will allow reverse flow in the exhaust system and pull the tissue or dollar bill TOWARD the pipe every so often



Misfires on one bank caused by "something in common between the 3 cylinders) will still usually cause a 0300 because a sensor will impact all cylinders of that bank.
A code for a single cylinder will usually mean something specific to that cylinder, not something shared.

Here's your "compression tester". (mine is showing age at 50 years!)
There are so many means of diagnosing a misfire - I usually only use this to nail down other issues, like rings, piston issues and so on.

Mine is very similar with hose . Very old belong to my uncle Whitman (whitey) we called him..

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[zxd9]

Well, now the local Jeep crew can't figure out what's going on so a STAR case has been opened with Jeep. It's been two weeks since I brought it in. I have a camping trip end of April. Gotta say I'm not too impressed with troubleshooting skills. They could have replaced a few cheaper parts for less than the labor they've put into it so far and narrowed down the search. When there's not an obvious solution, sometimes you have to implement a process of elimination approach instead of spinning your wheels.

 

[ShadowsPapa]

When there's not an obvious solution, sometimes you have to implement a process of elimination approach instead of spinning your wheels.

That statement flies in the face of any true experienced, good troubleshooter - no way.
You can always diagnose things, not throw cheap parts at it in a process of elimination.
They just don't know how to troubleshoot - if it's off their laminated card or computer programming.
They could throw hundreds in parts and labor at it and still not even be close - then what? Since it wasn't the solution - are you going to eat that?
That's an insult to true experienced and GOOD troubleshooters.

There are times it truly DOES take STAR team to get involved. I had a case where there wasn't any way without gathering information on dozens of similar cases - then the problem was finally found.
And no amount of parts swapping would have resolved it at all - there wasn't any part or group of parts that would have resolved it or narrowed it down.
It literally took engineers to figure it out.

 

[zxd9]

That statement flies in the face of any true experienced, good troubleshooter - no way.
You can always diagnose things, not throw cheap parts at it in a process of elimination.
They just don't know how to troubleshoot - if it's off their laminated card or computer programming.
They could throw hundreds in parts and labor at it and still not even be close - then what? Since it wasn't the solution - are you going to eat that?
That's an insult to true experienced and GOOD troubleshooters.

There are times it truly DOES take STAR team to get involved. I had a case where there wasn't any way without gathering information on dozens of similar cases - then the problem was finally found.
And no amount of parts swapping would have resolved it at all - there wasn't any part or group of parts that would have resolved it or narrowed it down.
It literally took engineers to figure it out.

I hear ya. In my troubleshooting world it is SOMETIMES more cost effective to narrow down the scope and then to replace parts. My customers are losing tens of thousands of dollars an hour when a manufacturing line is down. And yes, this method is sometimes used when we're footing the bill under warranty.

It took two weeks to replace my cam shaft and related parts. Now it fails two weeks after they worked on it. Two weeks later and no closer to a resolution. They should have called in for support sooner. Does it really take two weeks (80 hrs) to work thru the troubleshooting flow chart or are they working on it an hour or two and then moving on to something else they can get out the door and make some money on? Not sure how they work internally. (Just called dealer to get update and they said tech is not dedicated to my vehicle only.) My customers and my boss expect full attention until resolution is made. Maybe I expect too much.

 

[Stan H]

That statement flies in the face of any true experienced, good troubleshooter - no way.
You can always diagnose things, not throw cheap parts at it in a process of elimination.
They just don't know how to troubleshoot - if it's off their laminated card or computer programming.
They could throw hundreds in parts and labor at it and still not even be close - then what? Since it wasn't the solution - are you going to eat that?
That's an insult to true experienced and GOOD troubleshooters.

There are times it truly DOES take STAR team to get involved. I had a case where there wasn't any way without gathering information on dozens of similar cases - then the problem was finally found.
And no amount of parts swapping would have resolved it at all - there wasn't any part or group of parts that would have resolved it or narrowed it down.
It literally took engineers to figure it out.

I have to agree here , sighting my recent me mechanic escapades as an example.

So last month my Jeep threw a code .
Code said Failure to complete closed loop fuel circuit. So I looked up the possible causes. It list 5 different sensors as the culprit. I have way in excess of 100k and so I felt strongly that it was probably the O2 sensor master. Buuuuut ,I decided to throw everything at the wall and see if it stuck.
I bought a crank sensor,map sensor , O2 master bank 1 sensor, PCV valve, water temp sensor . I threw them all on the truck and slam bam wouldn't ya know the code went away.
This is what's called a hope and a prayer. It isnt scientific , I aint skilled enough to know if the corroded water temp sensor was it or the globbed up Map sensor , or the very old looking O2 sensor or the PCV valve that the rubber ring was slightly wore down on one side . The crank sensor didn't look bad but the power increase afterward was an indicator that any or all were well in need of replacement
In my opinion the shade tree mechanic is a fixer a parts thrower like me . He has certian set of skills and not afraid to use them
And in the same instance If it isn't plain as the nose on his face it is beyond his abilities.

Some times an engineer is needed and technicians may not be able to figure it out .
My 2 cents worth. Allow me to introduce myself . My name is Stan ,I'm a shade tree mechanic .and a Jeep owner.

 

[Hootbro]

Well, now the local Jeep crew can't figure out what's going on so a STAR case has been opened with Jeep. It's been two weeks since I brought it in. I have a camping trip end of April. Gotta say I'm not too impressed with troubleshooting skills. They could have replaced a few cheaper parts for less than the labor they've put into it so far and narrowed down the search. When there's not an obvious solution, sometimes you have to implement a process of elimination approach instead of spinning your wheels.

The warranty approval process keeps the dealership techs many times in narrow swim lanes from corporate or they do not get paid. Does not encourage outside the box thinking.

 

[ShadowsPapa]

The warranty approval process keeps the dealership techs many times in narrow swim lanes from corporate or they do not get paid. Does not encourage outside the box thinking.

But on the other hand - it does keep those who toss parts at stuff until they accidentally fix it from racking up a big parts bill for stuff that was never the issue to begin with.

My take is - a tech who can troubleshoot will figure it out won't have a problem because the factory warranty process won't interfere.

I hate the "let's try this and see if that helps" method. It reminds me of "my battery won't stay up, what's the issue" on all of the Fakebook car pages where people come in "bad battery" or "bad voltage regulator" or "bad alternator" or "loose belt" and the poor original poster replaces everything and still has a problem - because of a loose ground wire that could have been found in 10 minutes of logical approach.

 

[zxd9]

Well, after 6 weeks in the shop they finally got a replacement cam shaft. Fixed the cam shaft timing error but still getting P0300 misfires.

Opening another Star case with Jeep. Already messed up one camping trip. Wonder how long this is going to go on. Even when they say it's fixed, I'm getting nervous about my AZ/UT trip in Sept.

 

[ShadowsPapa]

Well, after 6 weeks in the shop they finally got a replacement cam shaft. Fixed the cam shaft timing error but still getting P0300 misfires.

Opening another Star case with Jeep. Already messed up one camping trip. Wonder how long this is going to go on. Even when they say it's fixed, I'm getting nervous about my AZ/UT trip in Sept.

When are you getting those P0300 errors?
On startup from a cold start in the AM
On a warn start after a 20 minute or so shutdown?
Or - as you drive along, nothing seems to matter, it happens at random?

Trust me - it can matter - there are times being quite picky about tiny details can lead to finding a clue that results in quicker resolution. Anything you can do to add detail MAY help (can't say it will, but it may, and it's sometimes worth the effort if you can)

Do you have a way to determine any other codes?
Or - maybe it's still at the shop??

 

[zxd9]

When are you getting those P0300 errors?
On startup from a cold start in the AM
On a warn start after a 20 minute or so shutdown?
Or - as you drive along, nothing seems to matter, it happens at random?

Trust me - it can matter - there are times being quite picky about tiny details can lead to finding a clue that results in quicker resolution. Anything you can do to add detail MAY help (can't say it will, but it may, and it's sometimes worth the effort if you can)

Do you have a way to determine any other codes?
Or - maybe it's still at the shop??

It's still at the shop. Adviser said they are random. Data was gathered and sent to Jeep.

 

[ShadowsPapa]

I had a weird warm/hot restart misfire on occasion. There's a TSB later than this hot-restart misfire PDF - mine was one that submitted info to STAR and got a later TSB for a PCM flash for the final fix. When mine went in, they were still gathering information.
Of course any tech would know any time any of the valve train components are replaced, you need to push the PCM to do a CCDIFF relearn - be it a cam, sprocket, chain, phaser, whatever, they likely know what to do from there.

 

[zxd9]

OK, it's been a few days shy of 2 MONTHS and they drove 257 miles while my truck was in the shop. Got it back yesterday.

For informational purposes I wanted to share the tech's notes regarding the fixing of the P0300 error.

- Performed diagnostics for P0300 and P000A codes.
- Connected micropod and retrieved dtcs.
- Swapped vvl solenoids on bank 1, followed by swapping cam sensors.
- Performed cam/crank relearn followed by cam phaser cleaning routine.
- Updated PCM to latest software
- Open Star Case
- Removed valve covers and inspected cam phasers and oil pan and OCV for metal.
- Performed engine compression and leak down test and inspected bank 1 engine cylinders with borescope.
- No metal present
- Swapped O2 sensors from opposite bank, no change.
- Measured resistance on the K441 @ .33 Ohms/K900 @ .35 Ohms/K856 @ .37 Ohms/K44 @ .35 Ohms.
- Replaced bank 1 intake camshaft phaser & OCV. (Tech is then told to follow another star case)
- No misfires detected.

Findings Summary
Bank 1 intake cam phaser slow response caused by binding phaser. Which caused P0300. Also bank 1 intake oil control valve plunger not fully releasing causing P000A.

 

[Stan H]

OK, it's been a few days shy of 2 MONTHS and they drove 257 miles while my truck was in the shop. Got it back yesterday.

For informational purposes I wanted to share the tech's notes regarding the fixing of the P0300 error.

- Performed diagnostics for P0300 and P000A codes.
- Connected micropod and retrieved dtcs.
- Swapped vvl solenoids on bank 1, followed by swapping cam sensors.
- Performed cam/crank relearn followed by cam phaser cleaning routine.
- Updated PCM to latest software
- Open Star Case
- Removed valve covers and inspected cam phasers and oil pan and OCV for metal.
- Performed engine compression and leak down test and inspected bank 1 engine cylinders with borescope.
- No metal present
- Swapped O2 sensors from opposite bank, no change.
- Measured resistance on the K441 @ .33 Ohms/K900 @ .35 Ohms/K856 @ .37 Ohms/K44 @ .35 Ohms.
- Replaced bank 1 intake camshaft phaser & OCV. (Tech is then told to follow another star case)
- No misfires detected.

Findings Summary
Bank 1 intake cam phaser slow response caused by binding phaser. Which caused P0300. Also bank 1 intake oil control valve plunger not fully releasing causing P000A.

Soooo your running good now I take it huh?

 

[zxd9]

Soooo your running good now I take it huh?

Well, the first 8 miles were OK. We'll see.

 

[Stan H]

Well, the first 8 miles were OK. We'll see.

Well keep us up to date,
I know a Jeeper who replaced a 3.6 in a 2018 and he was having akot of similar codes and the button (oil control valve plunger was stuck on one of his also and He figured it out by a stroke of luck digging into it.

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