Iron increase?

[The_Captain]

I have a 2020 Jeep Wrangler JLU 3.6 v6. I got my latest oil analysis back and iron has went from 16ppm to 28 ppm. Both intervals were around 5k with just over 200 miles difference. The other variables is late summer/Fall on the 16ppm and all winter for the 28 ppm sample and approximately 200 more miles. The other variable is I didn't drive my Jeep the last month before the 28 ppm sample. It would sit for days without being driven because I got car from my job to drive. My theory is that due to the days of sitting without running caused dry start up wear plus wear numbers trend up in colder weather? The rest of my numbers were spot on and nothing noted by Blackstone. Your theories?

 

[Lubener]

I agree with your theory.

 

[demarpaint]

Your theory could be correct, the winter months can change things a lot. How many miles are on the Jeep? The difference of 12 ppm iron in all honesty is nothing to be concerned with imo, we're talking parts per million here, and they aren't as accurate as many people believe them to be. It could also be the margin of error. My 3.6L Jeep sits for weeks at a time sometimes and the UOA results between when it is driven a lot and when it sat a lot were not much different at all.

 

[BMWTurboDzl]

I suspect that the oil was not run up to operating temperature when the winter sample was taken.

 

[JoelB]

Are you remote starting and idling it more in winter?

 

[CarbonSteel]

I had a similar experience with mine where it went from 12PPM to 36PPM for no apparent reason. The run with 12 was the first time I used RTG and 36 was the second. I am writing it off as the engine settling into a new brand of oil in conjunction with extended (10+ hours) of highway miles through the mountains in CO/WY/MT.

Will see what the next one shows.

 

[kschachn]

Yes warm-up wear, not startup wear.

 

[wwillson]

I have doubts that starting a few times after sitting would cause that much wear.

When you change your oil filter, let it drain for a couple days, then cut the endcaps off. Take the remaining paper element and stretch it out it the bright sunlight. You will be amazed at how much metal you see in the paper, especially on a newish engine. Because of this, I wouldn't give much thought to metal increasing or decreasing for the first 25,000 miles.

There is also a big problem with lab errors on the cheap fast UOAs.

I wouldn't worry about it.

 

[4WD]

I have doubts that starting a few times after sitting would cause that much wear.

When you change your oil filter, let it drain for a couple days, then cut the endcaps off. Take the remaining paper element and stretch it out it the bright sunlight. You will be amazed at how much metal you see in the paper, especially on a newish engine. Because of this, I wouldn't give much thought to metal increasing or decreasing for the first 25,000 miles.

There is also a big problem with lab errors on the cheap fast UOAs.

I wouldn't worry about it.

Yeah … DN often mentioned some don’t get real low until after 20k …
Mine is coming up on 6k and I don’t run UOA.
Would not want to be an asperity … people treat you rough

 

[Donald]

With UOA you look for trends. Not much should be based upon any one UOA.

 

[ka9mnx]

Sitting = Rust...

 

[demarpaint]

Sitting = Rust...

Maybe sitting for months, not weeks, and even months is a stretch imo. I've pulled my fair share of heads from engines that were sitting for a lot longer than the OP's Jeep and saw zero rust on the cylinder walls, or the valve train. Even lawn mowers, snow blowers and power washers that I worked on with cast iron cylinder sleeves that sat for a year or more had no rust. Come to think of it my brother and I pulled the head off a Chevy 250 I6 from a boat run in salt water about three months after it was pulled from the water, no rust on engine internals.

 

[Odd_Ball]

Presumably if you're not driving it much the oil is sitting in the sump much longer than normal. Maybe just over the extended time more iron is leaching into the oil?

 

[PimTac]

Presumably if you're not driving it much the oil is sitting in the sump much longer than normal. Maybe just over the extended time more iron is leaching into the oil?

I’m not sure how iron could leach into oil.

 

[Blinker]

Sitting = Rust...

 

[wwillson]

Sitting = Rust...

There actually would be more oxidation operating at temperature, which is why there are corrosion inhibitors in motor oil. Labs run corrosion tests at high temperatures, because chemically oxidation happens much faster at higher temps. Maybe @MolaKule or @JHZR2 could add some chemistry to this post. (pun intended)

 

[Odd_Ball]

I’m not sure how iron could leach into oil.

Maybe I'm misremembering but I thought some oils (Mobil 1 in my recollection) were famous for picking up some iron from the sump. I thought it was a characteristic of oils with some POE content. It's been a long time so I could be completely off base. We are talking about small quantities here (a delta of 8 ppm). If you put oil in a steel container and left if for a year I'd be sort of surprised if you didn't find some traces of the container in the oil.

Again, I may be misremembering.

 

[4WD]

Maybe sitting for months, not weeks, and even months is a stretch imo. I've pulled my fair share of heads from engines that were sitting for a lot longer than the OP's Jeep and saw zero rust on the cylinder walls, or the valve train. Even lawn mowers, snow blowers and power washers that I worked on with cast iron cylinder sleeves that sat for a year or more had no rust. Come to think of it my brother and I pulled the head off a Chevy 250 I6 from a boat run in salt water about three months after it was pulled from the water, no rust on engine internals.

Yeah … watching the junk yard shows I’m amazed at the condition of some motor insides …
The exterior condition might lead you to think they are hopeless … but the oil saved the day …

 

[demarpaint]

Yeah … watching the junk yard shows I’m amazed at the condition of some motor insides …
The exterior condition might lead you to think they are hopeless … but the oil saved the day …

I watch those shows too from time to time. After seeing that 250 I6, which spent its entire life in salt water was in good shape internally even after sitting in the driveway as long is it did before we tore into it. As I said it sat in the driveway for at least three months, probably more. That confirmed to me that oil leaves enough of a protective film not to worry about a car sitting a few months in a driveway or garage w/o being used is going rust internally.

 

[4WD]

I watch those shows too from time to time. After seeing that 250 I6, which spent its entire life in salt water was in good shape internally even after sitting in the driveway as long is it did before we tore into it. As I said it sat in the driveway for months. That confirmed to me that oil leaves enough of a protective film not to worry about a car sitting a few months in a driveway or garage w/o being used is going rust internally.

Yeah … BrocL used to be the sultan of old motors here … marine, road, farm … made a number of comments about residual oil everywhere