2015 3.6L Pentastar Cylinder Borescope Result

[explorer2030]

Great thread, but if you keep looking for problems, you'll find them. If you are hankering for a new ride, get it and trade this one in or sell privately to someone that needs a car with a very well researched engine.

I guess my ultimate goal here is to try to objectively as possible determine if this engine is healthy enough to make it to 300,000 miles, or another 12 years. I don't really want to sell the vehicle, but I would like to get out of it now while it still holds decent resale value if I can determine it's likely to need major repairs within this time frame. I don't want to have to do any further top end work other than maybe rocker/lifters, so additional head replacements, bottom end work, or a new engine and I'm out.

 

[Quantico]

I think your engine is fine. I see only flaking carbon which is pretty normal.. i dont like pinging. Dumb question.. are you sure you got a good thermostat when you swapped ?? A high or low temp can cause pinging. Not saying you have an issue... just asking.
I have looked at a lot of bore scope pics of 3.4 aprox porsche engines as I have been shopping. And your pics would not bother me if I was buying a jeep.
My advice is to run the slightly higher octane gas and maybe change to 5 w 30 high mileage oil. Even if you needed 3 grand of engine repairs at 300 k miles its not a bad cost for the use.
My other advice is not to worry about the engine. But changing trans fluid and both diff fluids and brake fluid and coolant is always smart.
One question I have is this engine difficult to purge the air out of the cooling system completely ?? The pinging can be from air in the cooling system causing high cylinder temps.. again just asking.

 

[Hootbro]

Dude, put the tools away and just drive it. Nothing indicates anything other than normal in service wear.

There is no Magic 8 Ball for what the future holds. Make an adult decision, but if you are looking for validation because of a subconscious want to trade, the data so far does not support a unhealthy engine

 

[HemiBenny]

I guess my ultimate goal here is to try to objectively as possible determine if this engine is healthy enough to make it to 300,000 miles, or another 12 years.

That requires a "crystal ball", which none of us here at BITOG have in our possession.
It's fine, put it all back together and start driving it toward that 12-year/300,000-mile goal.

 

[demarpaint]

I guess my ultimate goal here is to try to objectively as possible determine if this engine is healthy enough to make it to 300,000 miles, or another 12 years. I don't really want to sell the vehicle, but I would like to get out of it now while it still holds decent resale value if I can determine it's likely to need major repairs within this time frame. I don't want to have to do any further top end work other than maybe rocker/lifters, so additional head replacements, bottom end work, or a new engine and I'm out.

A lot can happen over the next 178K miles, that is not apparent now. Lets not forget the transmission, suspension, AC system, etc. IMO at the moment the engine appears to be in decent shape for the miles. A cam and lifter/lifters can fail, along with a head/heads, etc, there's a lot to be concerned with over the next 178K miles. JMO

 

[explorer2030]

I understand that it's not possible with 100% certainty to determine if the engine will achieve 300,000 miles, however, I believe that I should be able to make a call with a high degree of likelyhood. We should be able to say with its current condition all else equal whether this engine has the "potential" to make 300,000. That's really all I want to know, because I get that someone could crash into me next week and total the vehicle.

 

[explorer2030]

The borescope gives a terrible picture and (I believe) erroneously makes the valves look like there is something wrong. I think those are carbon deposits, not pits. Same with the edge of the valve. Not erosion, but more likely to be uneven carbon buildup.

I made some adjustments to the camera which I think has increased the quality of the images a bit. I also took a more thorough set of photos of each cylinder.

Cylinder 1

Cylinder 5

 

[OVERKILL]

Sounds like it's very healthy to me. Put it back together and drive it.

 

[DuckRyder]

I see nothing wrong with any of this, i would drive it...

 

[explorer2030]

I think your engine is fine. I see only flaking carbon which is pretty normal.. i dont like pinging. Dumb question.. are you sure you got a good thermostat when you swapped ?? A high or low temp can cause pinging. Not saying you have an issue... just asking.
I have looked at a lot of bore scope pics of 3.4 aprox porsche engines as I have been shopping. And your pics would not bother me if I was buying a jeep.
My advice is to run the slightly higher octane gas and maybe change to 5 w 30 high mileage oil. Even if you needed 3 grand of engine repairs at 300 k miles its not a bad cost for the use.
My other advice is not to worry about the engine. But changing trans fluid and both diff fluids and brake fluid and coolant is always smart.
One question I have is this engine difficult to purge the air out of the cooling system completely ?? The pinging can be from air in the cooling system causing high cylinder temps.. again just asking.

I replaced it with a new Mopar thermostat from the dealership which I believe is 203F. I can't be sure it's not defective, but I have monitored coolant temps when driving and find that the new thermostat typically cycles between approximately 203F and 212F. I replaced the old thermostat shortly after the check engine light came on, but I think it had been running cooler ~185F for a month or more before the computer tripped the code.

I am currently running 92 octane because I have been fueling at Costco for about a year and they don't offer 89 octane, otherwise I will run 89 octane top tier from Arco or occasionally Chevron which also eliminates the pinging. I used to run Chevron more often, but can't justify .80 a gallon more for the stuff.

I replace all fluids on a regular schedule. I typically go 5K engine oil, 30K manual trans/transfer case/differentials/power steering/brake fluid, ~75K coolant.

The engine is very difficult to purge air which is why I use an airlift 550000 vacuum coolant filler per the service manual, and follow that up with a spill proof funnel bleed while idling up to 212.

 

[explorer2030]

Sounds like it's very healthy to me. Put it back together and drive it.

Can't put it back together until I finish the repair on the leaking the oil cooler, which is what prompted the engine health analysis.

 

[OVERKILL]

Can't put it back together until I finish the repair on the leaking the oil cooler, which is what prompted the engine health analysis.

View attachment 134587

Well yes, I mean, finish the repair first, lol.

 

[JTK]

Are you using the new Doorman all aluminum oil filter / cooler assembly or are they still hard to come by?

 

[explorer2030]

Are you using the new Doorman all aluminum oil filter / cooler assembly or are they still hard to come by?

I originally was going to purchase the Dorman, but they are out of stock until February. Apparently they can't keep up with continuous demand, so they make them in batches and release them every few months until they sell out. I ended up going with the latest design Mopar housing because I did get 122,000 miles out of mine, and the new one is supposed to have a low failure rate.

 

[explorer2030]

Done any oil analysis? If so, how is the iron wear? Even in 2022, these Pentastars are still having bad cam and lifter or rocker arm issues depending on what generation Pentastar.

Here is my only oil analysis which I did at 62,715 because I was losing coolant in the overflow bottle, and wasn't sure where it was going. I recently took a sample of oil after I noticed the leaking oil cooler because I also noticed coolant loss and what appeared like coolant mist on some parts under the hood. Was a little concerned about getting coolant in the oil if the oil cooler cracked in the right place, so I might do another oil analysis soon.

 

[JTK]

I originally was going to purchase the Dorman, but they are out of stock until February. Apparently they can't keep up with continuous demand, so they make them in batches and release them every few months until they sell out. I ended up going with the latest design Mopar housing because I did get 122,000 miles out of mine, and the new one is supposed to have a low failure rate.

Good deal. I'd use OEM as well, given you got ~8yrs and 122K miles out of the factory unit.

 

[Hootbro]

Here is my only oil analysis which I did at 62,715 because I was losing coolant in the overflow bottle, and wasn't sure where it was going.

Like how much coolant? On both my Wrangler JL and 2020 Gladiator, the coolant may have dropped from the MAX to the MIN line in about a year and that was approx 8oz. I did an oil analysis also on my 2020 Gladiator, showed no coolant markers. There has been some debate on the Gladiator forums that the coolant system is not a perfectly sealed system at the pressure overflow bottle and that some coolant evaporation over time is normal. I am inclined to believe that from my experience.

 

[explorer2030]

Like how much coolant? On both my Wrangler JL and 2020 Gladiator, the coolant may have dropped from the MAX to the MIN line in about a year and that was approx 8oz. I did an oil analysis also on my 2020 Gladiator, showed no coolant markers. There has been some debate on the Gladiator forums that the coolant system is not a perfectly sealed system at the pressure overflow bottle and that some coolant evaporation over time is normal. I am inclined to believe that from my experience.

It would lose a few inches or so. Jeep revised the radiator cap for mine recently from 18psi to 17psi, and I have come across at least 3 people who have installed the new cap state that their coolant levels no longer drop, and the overflow bottle works better. I'm planning on giving the new cap a try myself.

 

[SC Maintenance]

So you think I should return this leakdown tester for a different one? Is it possible that the leakage is so low that the tester just doesn't register it? There is definitely a slight bit of air escaping the oil fill tube on all cylinders, and by sound/feel it appears to be even across cylinders. Unfortunately, I won't be able to retest it for a while because by the time I would be able to get a new tester I'm going to have to complete my repair and button the vehicle back up.

I would agree with you. Your hearing the bleed down but your gauge isn’t sensitive enough to read it. I would guess it’s small enough you don’t need to concern yourself about it.

As for the gauges - they don’t seem all that accurate. I would swap them for next time - if there is a next time.

 

[4WD]

The divot you are seeing is on all the pistons, it's the locating mark so they are installed the right way. Here's an example on a new piston:

That’s after one OCI with VRP