Question Concerning 10k OCI & Timing Chains

[BISCUT]

I took me a while to get comfortable enough with a 10K OCI in my 17 Subaru Outback. I got there! UOA came back excellent so no issues on the data. I'm using M1 EP 5-30 and Fram Ultra filter. The nagging questions I've had is are there any concerns about wear of timing chains running a longer OCI. Verdict?

 

[slacktide_bitog]

Is 10k the factory recommended OCI?

M1 EP and Fram Ultra should be capable of 10k with no problem. You forgot to mention you have the 3.6 which is much better than Subaru's 4-cylinder engines. This makes a difference. Subaru uses a higher bypass spec for their newer 4-cylinders that doesn't apply to the H6. Fram is the OE supplier for Subaru but doesn;t make the 4-cylinder high-bypass filter available for the aftermarket, so if you had the 4, I'd say to go with Wix instead.

Anything d1g2 should be fine for timing chains.

 

[BISCUT]

Sorry, it is a 3.6. Not sure of the factory spec I believe it is 7500k normal driving but that may even be for semi.

 

[Bottom_Feeder]

Curious why you're concerned about the timing chains specifically?

 

[WylieCoyote]

I think your concerns are legitimate. Google GM 3.6 & 2.4 timing chain issues. GM timing chains can't be the only makes affected by long OCI.

 

[Oro_O]

Curious why you're concerned about the timing chains specifically?

A lot of timing chain failures get blamed on oil. I see this with German makes a lot - rather than blaming the bad inherent design (plastic runners, inaccessible location, etc.).

I'm curious about this too and have been thinking about it. Appreciate the OPs question even if I can't help.

 

[Pelican]

A lot of timing chain failures get blamed on oil. I see this with German makes a lot - rather than blaming the bad inherent design (plastic runners, inaccessible location, etc.).
I'm curious about this too and have been thinking about it. Appreciate the OPs question even if I can't help.

One of the reasons why I don't go for long OCI is that the oil collects deposits, crud, etc which will have the detrimental effect of abrasion on the chain even if lubrication is still OK. This will lead to premature failure of the chain or at least affect timing due to slack.

 

[Gene K]

I'm highly scepitical that any reasonable OCI for the engine design and oil in use contributes significantly to the issue.

I know guys that had timing chains replaced on Gen 1 3.5 Ecoboost at less than 40,000 mi with 3,000 mi OCI with M1. I also know guys with 300,000+ mi on 10,000 mi OCI of MC Blend without issue. I wish it was as simple as drain intervals but from what I've seen it isn't.

 

[ChrisD46]

*Just because an oil filter + long drain oil like M1 EP are capable of a possible 10K OCI doesn't mean you should do so . I could see running a Fram Ultra oil filter for two 7,500 mile OCI (with inspection afterwards) and changing the oil at 7,500 mile intervals . Better deposit control mainly along with less shearing , fuel dilution , more add pack left , etc. the result . A 10K OCI for me would only be feasible with majority of mikes straight interstate travel with little traffic . Once city or even suburban driving is added in , a 10K mile OCI becomes more of a challenge.

 

[2EHA]

The chains on most euro engines and the ford mod motors in my experience really don’t wear out all that much, usually plastic guides fall out and causes noise long before an elongated chain can become a problem.

Good guide rails usually have a metal backing plate to warn that enough slack exists to jump time. On many DOHC engines keeping the short secondary drive chain tight and tensioned is much more critical than with the primary drive.

The 70s Mercedes V8 had all-aluminum guide rails, a real lose-lose scenario with heavy wear and lots of noise.

 

[Gebo]

Biscuit, it seems you aren't quite comfortable enough with the 10k OCI. I have reduced most of my cars to 3K OCI and I am most comfortable
as I know my oil and filter won't ever be a problem. Regardless of any oil testing, you know what you should do. You had to "make" yourself extend
your OCI's to 10K, right? Go back to the OCI that removes your stress.

At least follow the most rigid severe service OCI that Subaru recommends. What is their recommendation for severe service?

Remember car manufacturers are in business to sell cars. They don't want cars to last "forever". My noodle brain has me changing oil at 3K
like my father did many many years ago. I used to make fun of him. Amazing, huh?

Some people will make fun of me but I don't mind making all those extra trips to AA with my 5 gal container of used oil.

 

[BISCUT]

According to the Subaru manual my Outback came with OCI is 6k normal condition 3k severe. What I don't like is it's blanketed across the 2.5 4 and the 3.6 6. It makes me wonder how much is due to the previous issues with 2.5 burning oil. And I believe these recommendations are for standard oil not synthetic.

I'm not loosing sleep over 10k OCI with M1 EP but it was a question I was wondering about. These types of questions intrigue me. My thinking on this also has to do with the fact I am the original owner and know the maintenance on the vehicle with certainty. I know it's clean. If I had bought it with 20-30k or more miles I'd have a level of uncertainty. Nothing scientific based just thoughts.

 

[SwampSurvivor]

I'm not sure a GDI engine with a single long timing chain would be comparable to a port injection engine with two timing chains and tensioners.

 

[gregk24]

GDI engines produce soot, that soot becomes suspended in the oil. That oil is the same oil that lubricates the chain and other components. The longer the OCI the more contaminants are in suspension "lubricating" your timing components. The longer your OCI the higher chance you have of prematurely wearing out your timing chain. If you want long life out of the chain, change it more frequently than 10K.

This has been proven on GM's 2.4 and 3.6 engines. They spec'd too long an OCI and timing chain failures resulted. Yes, it was bad design but it shows that more frequent OCI's can mitigate the problem.

VW (and many other manufactures) have struggled with certain engines and their timing chains as well. Our 2014 Jetta started exhibiting symptoms of a "stretched" chain and upon some reading I found it was a fairly common issue with the early 1.8 TSI's. Shortly after discovering that potentially very costly repair (and for a variety of other reason) we traded the 2014 for a 2020 Jetta 1.4 TSI equipped with a timing belt. I didn't want to go down the VW timing chain path again, not yet. They have a history of timing issues and clearly they didn't have it resolved in 2014.

Sorry for getting off on a rabbit trail. My recommendation is to NOT do extended OCI's in timing chain equipped engines and expect a long service life.

 

[Gebo]

Well, I'd do 3K based on what your owner's manual says.

 

[Bryanccfshr]

Easy enough to do a dump and fill at the severe service interval and change the oil and filter at the regular interval.

 

[bluesubie]

According to the Subaru manual my Outback came with OCI is 6k normal condition 3k severe. What I don't like is it's blanketed across the 2.5 4 and the 3.6 6. It makes me wonder how much is due to the previous issues with 2.5 burning oil. And I believe these recommendations are for standard oil not synthetic.

I also feel they dialed back the OCI due to consumption in the 2.5's, but the manual doesn't mention longer OCI's with synthetic.

Synthetic oil
You should use synthetic engine oil that meets the same requirements given for conventional engine oil. When using synthetic oil, you must use oil of the same classification, viscosity and grade shown in this Owner’s Manual. Refer to “Engine oil” 12-4. Also, you must follow the oil and filter changing intervals shown in the Warranty and Maintenance booklet.

 

[BISCUT]

GDI engines produce soot, that soot becomes suspended in the oil. That oil is the same oil that lubricates the chain and other components. The longer the OCI the more contaminants are in suspension "lubricating" your timing components. The longer your OCI the higher chance you have of prematurely wearing out your timing chain. If you want long life out of the chain, change it more frequently than 10K.

This has been proven on GM's 2.4 and 3.6 engines. They spec'd too long an OCI and timing chain failures resulted. Yes, it was bad design but it shows that more frequent OCI's can mitigate the problem.

VW (and many other manufactures) have struggled with certain engines and their timing chains as well. Our 2014 Jetta started exhibiting symptoms of a "stretched" chain and upon some reading I found it was a fairly common issue with the early 1.8 TSI's. Shortly after discovering that potentially very costly repair (and for a variety of other reason) we traded the 2014 for a 2020 Jetta 1.4 TSI equipped with a timing belt. I didn't want to go down the VW timing chain path again, not yet. They have a history of timing issues and clearly they didn't have it resolved in 2014.

Sorry for getting off on a rabbit trail. My recommendation is to NOT do extended OCI's in timing chain equipped engines and expect a long service life.

GDI my engine is not. Valve train is relatively easy on the oil as well. Two different animals. GDI and TGDI IMHO seems to make a huge different in contaminants in the oil. TIG on this board has been doing 10k OCI for many many miles on multiple Ford engines. There's commonalities to chain failures; direct injection with extended OCI and plastic tensioners have been raised.

 

[anndel01]

I've replaced several timing chains on Toyota 22R-E 4 cyclinder engines (1989-1994) and most owners had OCI's of 5000 miles which is in the owner's manual, some at 3000 if they were towing or doing lots of offroading. The chain just stretched at 90,000-150,000 miles probably because Toyota went from a dual-row chain to a single row chain. I replaced mine at 155,000 miles and with OCIs at every 5,000 miles.

 

[gathermewool]

From reading here it seems that timing chain issues seem to be more related to bad designs than OCI, shorter OCIs being a bandaid.