Could synthetic have saved this Camry?

Why are people suddenly concluding low tension rings are an issue? They've been standard for decades folks, they aren't a problem.
The Ford dealership did a lot of warranty engine replacements on 302's in trucks when they went to low tension piston rings in the 90s. Those were before my time (I worked there in 2003-2005 or so) but there was a tsb about it and my friend/coworker at the time actually worked there when they were repairing them for that problem.
 
No. Almost all of these oil burners used 0W20 synthetic from Day 1.
As we've learned, there are tests showing that using ever thinner oils, with HTHS as low as 2.2 did not increase cylinder and ring wear.
However, there are also equally valid tests that show increasing ring and cylinder wear as viscosity drops.
Pick your poison,,, but it's good to remember that the real world has a way of, over time, weeding out the nonsense. And we are seeing oil consumption issues where we did not before. Plenty of Prius, Honda, Acura, and other engines consuming oil with relatively low miles, nearly all fed a steady diet of the recommended synthetic.
 
The Ford dealership did a lot of warranty engine replacements on 302's in trucks when they went to low tension piston rings in the 90s. Those were before my time (I worked there in 2003-2005 or so) but there was a tsb about it and my friend/coworker at the time actually worked there when they were repairing them for that problem.
Mustang (302HO) got low tension rings in 1985, it was never an issue with the cars from what I recall.

Now, Ford DID go to hypereutectic pistons in like '92?

The trucks were late to go roller cam, like mid 90's? and were batch-fire, had their own intake, the lopo firing order and a few other oddities, so perhaps something there got buggered up? But I've never personally heard of this.
 
Which do you mean:

- they were on synthetic oil from day 1 (0w-20 being synthetic I imagine)

or

- 0w-20 viscosity ruined them?
0W-20 is exempt from the API ring deposit maximum. Combine low tension rings and poorly designed pistons with an oil grade allowed to leave more ring deposits than industry standard and you end up with a bunch of oil burners. The 0W-20 may not have ruined them outright, but I can't help think it was a contributing factor.

Ed
 
Just watched this video, it was very interesting. I was wondering how the cat was since it was burning 1qt every 150 miles, that’s insane. It took until near the end of the video for him to mention that the cat was ok. Wow, 100 quarts of oil he said it burned over time and the cat was still ok.

I like simple cars like that old Camry. Manual transmission, not too many fancy options… If that was my car and it was still in good condition, I’d do this repair too.

I wonder what Scotty would do? 🫲👋🫱
 
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Why are people suddenly concluding low tension rings are an issue? They've been standard for decades folks, they aren't a problem.
Ehhh.. @OVERKILL Maybe, in this case, it could be as simple as Toyota just didn't make them that well. I don't know that for a fact, no, BUT. (Engines were already assembled when they came in where I was at, they make them somewhere else, I want to say Kentucky is engine plant but not 100% sure on that.) Enter Toyota. 1ZZ-FE is same issue. The ZZ family replaced the extremely popular cast-iron block 4A engines.

Not enough oil drainage holes so maybe low tension rings are a great place for it to be blown by. Speculating.

I would be surprised if @CR94 1981 Mazda used full synthetic 0W-20 in 1981.

I'm not an expert on this but just because they have low tension rings. Not necessarily the bees knees. And could be contributing to not doing all that good a job.. maybe it IS where oil is getting "burned" if it is a pattern failure specifically to an engine family. Maybe other manufacturers dont have that issue maybe because they just make better engines/cars.

I get your point "Why blame the rings" maybe in this case it really is the rings.

My opinion of Toyota has changed also having had worked there.. they sure ain't the golden calf everyone thinks they are. Maybe some are OK, with maybe some exceptional examples, maybe from older cars when they weren't doing all this "Let's make everything better by making it worse" stuff they seem to be doing now, maybe not even specific to Toyota.

But if oil is getting past the rings.. perhaps they are alleging poor sealing, how rings operate (yes there are multiple rings.) Could just be that simple.

Again, with Toyota? Wouldn't surprise me.
 
0W-20 is exempt from the API ring deposit maximum. Combine low tension rings and poorly designed pistons with an oil grade allowed to leave more ring deposits than industry standard and you end up with a bunch of oil burners. The 0W-20 may not have ruined them outright, but I can't help think it was a contributing factor.

Ed
I wonder if the dexos1 spec many 0W-20s meet has criteria for piston ring deposits. There was talk here MMA/“star” polymer VIIs are a bit more resistant to degrading unlike OCP VIIs. Could that have an impact on ring deposits?
 
Why are people suddenly concluding low tension rings are an issue? They've been standard for decades folks, they aren't a problem.
Low tension rings can be a problem and certainly were in the 2AZ-FE, used mainly in 2007-2009 Camry. This is not new, nor sudden. Toyota engineers made that conclusion back in 2011. Toyota issued a TSB and redesigned the rings to a higher tension spec. Along with a slightly updated piston design, that solved the problem for good.

Unfortunately for the owners who didn't meet the minimum oil burn rate during the powertrain warranty period, they're stuck with doing the repair on their own dime. So, ironically, owners who used high quality oil and changed it frequently were more likely to miss out on free warranty repairs.

That said, Toyota's definition of "low-tension" may be very different from Ford's definition.
 
Mustang (302HO) got low tension rings in 1985, it was never an issue with the cars from what I recall.

Now, Ford DID go to hypereutectic pistons in like '92?

The trucks were late to go roller cam, like mid 90's? and were batch-fire, had their own intake, the lopo firing order and a few other oddities, so perhaps something there got buggered up? But I've never personally heard of this.
I was told they didn't see issues with the Mustangs either...but it could be that they were broken in harder than the trucks (better for seating the rings) or that they didn't sell many compared to the trucks (this was the north country). They also didn't see many issues with crown vics or grand marquis and they tend to get babied.
I personally knew a few people that blew up early 90s f150 302's back in the early 2000s. All I know is people that were working at the dealership before me told me it was due to the switch to low tension piston rings.
 
No. Almost all of these oil burners used 0W20 synthetic from Day 1.

Same vintage as the subject Camry and these cars used higher viscosity/hths oils. All of these, along with Honda and Toyota etc instituted longer drain intervals using synthetic.

This is more complex than just blaming conventional oil or viscosity or intervals or rings.

Screenshot_20230110_070500.jpg
 
I know that Subaru replaced a bunch of short blocks in Foresters due to this problem (low tension rings) some years back. We have a ‘17 Forester that doesn’t burn any oil at all, using 0/20, @ 60,000 miles. Our ‘17 Wrangler doesn’t use any either (5/20) @ 78,000. Both use syn oil, get changed at about 6,000 miles.
 
Low tension rings can be a problem and certainly were in the 2AZ-FE, used mainly in 2007-2009 Camry. This is not new, nor sudden. Toyota engineers made that conclusion back in 2011. Toyota issued a TSB and redesigned the rings to a higher tension spec. Along with a slightly updated piston design, that solved the problem for good.
Is this the updated piston design with more numerous and larger oil return holes? If so, then that's the root cause, not the rings. That TSB does indicate that the piston assembly was updated:
Screen Shot 2023-01-10 at 11.45.14 AM.jpg


And, if that's the case, then this is the 2nd time that's happened, correct? Because they had the same issue years earlier. I had a buddy with a Corolla "S" that was affected.

We previously discussed the 1ZZ-FE in this thread:
Unfortunately for the owners who didn't meet the minimum oil burn rate during the powertrain warranty period, they're stuck with doing the repair on their own dime. So, ironically, owners who used high quality oil and changed it frequently were more likely to miss out on free warranty repairs.

That said, Toyota's definition of "low-tension" may be very different from Ford's definition.
Think the definition is pretty universal. I'm not sure why Toyota has had piston/ring design issues, too much CAD and not enough testing? LOL!
 
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I was told they didn't see issues with the Mustangs either...but it could be that they were broken in harder than the trucks (better for seating the rings) or that they didn't sell many compared to the trucks (this was the north country). They also didn't see many issues with crown vics or grand marquis and they tend to get babied.
I personally knew a few people that blew up early 90s f150 302's back in the early 2000s. All I know is people that were working at the dealership before me told me it was due to the switch to low tension piston rings.
I do remember that oil consumption could be a problem if the PCV screen on the cars got plugged. That was an odd design, there being that metal mesh "filter" located below the PCV valve in the back of the intake, so you clearly couldn't see it.

It SOUNDS like you are describing the last couple of years just before they went roller?

As far as rotating assembly went, the HO got a different one from the LoPo (and had forged pistons up until 92), can't remember if the truck and panther cars got the same one or not? I know the cars had cast pistons. They obviously got different cams and the cars were roller from like 85 or 86 onward and SEFI, while the trucks were batch-fire. LoPo cars didn't get the E7TE's either, IIRC? been a few years though since I was deep in the 5.0L scene, so I may be forgetting or mis-remembering some of this.

I did skim the truck forum TSB's last night after you mentioned it and didn't see anything mentioning rings. Did see some stuff on engine knocking and oil fill procedure. You have piqued my interest, so if you can remember anything else, please let me know.
 
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