Courier CT update: first problem detected

Yesterday, after I changed my transmission fluid, I was told that I have my first real issue. A rear main seal leak. It's not bad, but were I to repair it, it would cost $2,000 at the dealer, and maybe a little less at my mechanic's. The dealer told me this is a 12-hour job.

My mechanic also told me this could have been caused by debris in the oil that made it past the filter. Since I run long OCIs (Oil Change Intervals, currently 26,000 miles), that may have allowed something to make it past the filter. He suggested I look into bypass filtration again. Long story short, I once looked into that to increase my OCIs but the cost difference wasn't worth the trouble. Since the filter on the bypass system is finer than the standard oil filter, it may be worthwhile just to avoid problems like this down the road.

I don't plan on fixing the leak right away, only when it's necessary. Just in case I run into another issue down the road where the transmission has to come out anyway.

 

Yes. Working on going further, but now I may need to scale back or just go with bypass filtration.

 

This is essentially what my mechanic meant. The long OCI means more stuff gets past the filter, and as you have heard, if the filter "maxes out," the bypass valve lets everything through, meaning more chances of something causing damage to a seal, which may be what happened here.

My research shows that beyond removing harmful particles from moving around the engine and causing problems, there are two other advantages to bypass filtration (which is why they are used so much in commercial fleets where you want to keep your engine running as long as possible); one, you reduce wear and tear on the engine because most engine wear is due to particles floating around with the oil and rubbing against the inside (some sites suggest bypass filtration essentially removes all engine wear, though I'm skeptical about this), and two, engine oil (modern synthetics mostly) basically never break down, and essentially only need changing because of the contaminants that a bypass system would clean up.

With such a system, I will have a much longer OCI, longer engine life, and I only need to change the filters, along with adding additives when they oil additive package runs out. Right now this is what I've learned, but I'm still researching it.

I also wanted to add that at 25,000 miles, only 1k short of my next oil change, my oil level is beyond the full mark (I have my shop add all 5 quarts instead of the 4.8 my car requires since I drive so much), so the leak I have right now is minimal and insignificant for the time being.

 

Thanks for this reply! I'll definitely look into all of this.

 

Hey! It's rolling just fine!

I'm about to hit 345,000 miles, and still no further issues. The leak is still minimal, and after discussing it further with my mechanic, he feels that a PCV valve might have done this (as it seems to be something a lot of folks replace or clean on their cars). At some point I will see if it would be easy to remove and clean on mine.

My last oil change interval was 28,500 miles, but my mechanic (who regularly looks inside my engine block through the opening where you add oil from) says that my engine isn't as clean as it used to be, and feels I should probably not keep extending the OCI. I tend to agree, just for longevity reasons, and will roll back to 25,000 mile OCIs. The oil report from the 28.5k OCI came back positive and the lab recommended I try 30,000 miles next time, but I think I pushed it and the filter enough as it is.

Otherwise, the car still drives great!

 

The thing is, my mechanic checks out my filter as well. At 28,500 miles on my last oil change, the filter I am using now (Wix 57064XP) is still holding up without any media disintegration, so I'm betting that going to 30k is no problem with one filter if I use the same one. I am just being cautious at this point because there is no incentive for me to keep going. There's no worthwhile savings going from 25,000 to 30,000 miles between oil changes.

I don't run a catch can, but I do have a magnetic drain plug on both my engine oil drain and transmission fluid drain. Both never show metal particles. Engine wear, according to the lab, is still great with very little wear.

Regarding the fuel treatment, and this goes to answer Trollbait too, I never use it even though my mechanic told me it may be worthwhile at some point. The reason I haven't used any is that I only use top tier gas. Of the over 900 fuel-ups I've done with this CT, only 5 or so have been non-top tier. The extra detergents are keeping everything pretty clean.

I'm going to talk to my mechanic in more detail to see what exactly causes my engine to look "not as new" as it did before, and see if there's anything worth doing, or if it's even an issue (it may just be the miles I have on the car and nothing to do with the OCI).

 

You're right, but the oil reports show no filtration problems. My last filter was breaking up earlier than this and so media could have gotten loose and damaged/killed the engine. A visual inspection showed that my last filter was not completely blocked up.

 

Blackstone Labs has a test where they run the sample through a centrifuge and measure the amount of insolubles to determine whether it's a safe amount of not. I believe this is how they see oil filter problems. They can also check air filter issues by measuring things such as Silicon in the sample.

Total percentage of insolubles should be under 0.6%, and I have gone from 0.2% to 0.4% across the 6 tests I've done. That, along with a visual inspection, showed that my oil filters have been working well and not bypassing much. The only issue was that the old filter type I was using (Mobil 1 Extended Performance) started to degrade (it uses a natural and synthetic media blend), so I switched to a full synthetic media type with the Wix XP.

 

The centrifuge test is designed to collect all particles, especially ones that can't be seen due to their small size, into one clump that can be measured. Based on their training and experience, they feel that anything below 0.6% is perfectly normal. This is how they determine whether enough is getting through the filter or not.

The fact that I tested 6 different OCIs, from 15k to 28.5k miles, with only 0.2% to 0.4% insoluble count across them, shows that time is not really much of a factor, at least not within my OCIs. This means that either the filter is doing its job, or that if it's failing, it's failing so slowly that it's moot anyway since I'd have to run 100k miles or more per oil change to see any issue.