Potential Cause of rumored GR86’s blown engine? Seal packing(RTV) was peeled off
 

I just randomly checked JDM info on Twitter and realized the rumour of GR86 blown engine has become a hot topic. I used google translate to read the report, and translate it directly “the cause is that the seal packing of the oil pan was peeled off and the strainer (oil pickup tube) inside the engine was clogged.” [Correction: The original tweet additional info: “I came to the conclusion that this seal packing was the packing that protruded from the timing chain cover and got caught by the chain and reached the strainer. In the case of this vehicle, it is not the sealant in the oil pan.”

I did find some cases on Twitter.


overall explanation with pics covered by the media, moby.jp
https://car-moby.jp/article/automobi...rge-of-recall/

The most well-known tweet
https://twitter.com/autogaragek2/sta...98245981212672

some owners just went to check their oil pan after that tweets
A JP racer Eijiro Shimizu from SHADE RACING team saw the same issue :
https://twitter.com/eijiro_5130/stat...83435098804225

- prevention method & engine disassemble
https://minkara.carview.co.jp/userid...9345/note.aspx


- case with pics
https://ameblo.jp/kurumabaka888/entry-12752811883.html
- more pics of clogged strainer
https://cartune.me/notes/Z9vHATmq3j
- more case
http://www.maruta-goya.com/wp_blog/archives/53450

- JP shop UNPARALLELLED tweet：https://twitter.com/unparallelled_1/...56222900740096

- https://twitter.com/GR86_RINA/status...01293883060225

- https://twitter.com/kakuni67174437/s...11725668098048
new BRZ: ZD8 delivered on 2021/9/1
17,500km with 6 circuit runs (7-8 hours in total)
Oil change is about 8 times in total after delivery

just find 2 more useful articles from JP that explain the situation and potential causes of the clogged oil pickup
https://www.vehiclefield.com/blog/41214/
https://www.team-mho.com/gr86-brz/

@Arash Changizian on Facebook, dropped the oil pan, with short video
https://www.facebook.com/MNIVETMX5/p...Tr8RWDfRJ3DGol

Also, there is a blogger(content uploader) on Weibo (Chinese social media), who actually have a chance to ask a dealer‘s chief mechanic in person regarding this issue on the 10th anniversary GR86 release site(FUJI 86 BRZ Style 2022)

https://weibo.com/1642346197/LDUG7AZot#comment
- Including the Racing factory team and GR86/BRZ CUP designated vehicles also confirmed sealant blockage. However, Just like the info from JP bloggers, even if the top of the filter of the pickup tube is completely blocked, the oil can be drawn from the other 4 sides because it's a five-sided/box-shaped design, not one sided (like pics below). So it is necessary to check the oil pressure frequently after intensive driving.

- No official recall for this issue. If the problem does occur during normal (non-extreme/aggressive, a further explanation of “normal" needed) driving, all vehicles with maintenance can have their engines replaced according to the warranty contract. It is necessary to pay attention that, to any failure accident in track driving, the manufacturer will refuse the warranty (you can read the Warranty Booklet for this, may just be applied on JDM).

- The design of the stock car is roughly corresponding to 90% of the driving conditions below 4000 rpm(non-intensive). It is necessary to make corresponding modifications for full track driving, such as the oil pan baffle plate. The baffle plate is to prevent the engine from oil starvation during high G cornering/acceleration when driving on a circuit. also, most of the RTV that peeled off will be blocked on it and will not fall off.

also, STI also provides the oil pan with baffle plate for BRZ CUP car(also suitable for GR86), the part number is ST11109Z2000, just google it. Or you can buy the plate from well-known aftermarket brands like Cusco/Tomei/GReddy, they are all suppliers for CUP cars, like the pic shown below.
- For potential prevention, besides the plate, you can check the dipstick regularly, since some owners suggested that the sealant may stick in the oil dipstick. And you can install an oil pressure metric gauge in advance to prevent low oil pressure.

The dreaded timing chain cover again?!

"Somehow a great response ...

By the way, as a result of verification, we came to the conclusion that this seal packing reached the strainer because the packing that protruded from the timing chain cover was caught in the chain.
In the case of this vehicle, it is not an oil pan sealant."

Arghh, it's like one of those things that might junk the engine over a long period of time. There does seem to be an over-enthusiastic application of RTV sealant shown.

The more things change, the more they stay the same.

just subie things

"The filter is made of five-sided box shapes, not one side. Therefore, as long as the oil surface is secured, it is considered that it will not go to zero hydraulic pressure due to too much debris. I'm supposed to be smoking from the 5th side."

I'd also like to smoke some 5th sided strainer. it would be good for people to get an oil pressure sender and gauge to make sure oil pressure is staying high as precaution

I am going to tell a little story here.
Back 2014 and 15 (long before the spring recall debacle) there were a number of mysterious engine failures due to oil starvation. I went back through older threads and managed to collect around 30 reported cases. Of the cases that actually gave detailed info there were more than 20 that included excessive sealant in the oil pickup. Of course there would have been many many more that never got reported here but with the data we had it was statistically probable that the majority of the failures were due to blocked passages and/or pickup tubes. All of the affected cars were very early 2013s

Many people wanted to ignore the sealant and stated that "there is no way there can be that much extra and it can't possibly get into the passages." Well the later failures due to bad sealant during the recall most certainly proved it could and does get into the passages and pickups if not applied correctly.

So, anybody that works in automotive manufacturing knows just how much is done by robots. In this case the sealant on the timing cover and oil pan are almost guaranteed to be put on by robot. It is exactly the sort of task that robots USUALLY do better than humans. Robots do however screw up (often because the human that taught the task did a piss poor job) on a fairly regular basis as well though. Yes these engines had been used for a short time in the Ascent but the differences in the overall construction likely means they had their own set of programing including the sealant application. Even being out by 1 millimeter or a few extra grams of material applied can give the results seen in the picture here. This type of failure is not unknown in the early production runs of anything new.

Odds are that if that was a total undisturbed stock engine there will be more than one with the same issue. Probably not many but enough to cast doubt on any of the very early production. If indeed the oil pan (as it appears to be) this time at least it is a far easier check than the timing cover. Getting the dealer to check may be difficult unless there are several failures and instructions come down from Subaru.

And people are surprised that some say to stay away from being an early adaptor of a new model car?

Timely thread. My GR86 is at the dealer waiting on a short block. Blew up at 5500 miles.

What are the early indications that this problem is going to happen?

blowup? as in hole through the block or just rod knock/spun bearing?

Just rod knock/spun bearing, block is intact.

Oil level was at MAX mark, factory fill.

Now i am super paranoid and would like to drop my pan just to take a peek. Was your GR ever tracked? How was it driven?

I would guess none, unless you are lucky enough for it to starve just enough to trip a low oil pressure warning (CEL?) but not cause damage.

I did not track it, but did autocross it regularly. It saw a lot of rev limit time, but that should 100% be in the engine use parameters.

In a stock engine with stock tune, the owners only responsibility should be to keep the oil and coolant levels in check and I was very careful about that.

Want to guarantee that if it does happen and they can see you've dropped the pan they're going to give you a hard time?

Just leave it. 5yr/60k powertrain warranty. If it's going to happen, it's going to happen well within that period.

challenge accepted. gonna drive it even harder now!

Very valid point. As Rusty mentioned, drive it like you stole it and make sure the oil is changed at the dealer for service records.

Can dealers actually deny warranty over documented self completed oil changes if this failure were to occur?

I keep receipts, pictures and full documentation every time I change my oil. I'd rather not have to drive an hour and a half to get Subaru to change it.

No. As long as you have the documentation to prove the work.

Like TCoat said, you don't have to. I take my cars to a reputable indy shop to do it because I'm lazy and don't want to screw with having to dispose of the used oil.

I can do it during the week, and log on to their WiFi and keep "working" and essentially get a few hours out of the home office.

I want to assure that most warranty claims will need to be covered by Dealerships to submit to OEM's with sufficient documentation to prove maintenance intervals. Question is if you put liability on the shop, dealer, or the manufacturer as those claims will imply differences on the cause of the defect. As long as you monitor your Powertrain with appropriate servicing, the limited or extended warranty you have with the manufacturer (Subaru in this case) will be what the claim will need to be issued under.
I also want to echo TCoat's explanation and provide context for what these sealants usually can lead to. You can have RTV (Room-temperature vulcanizing) materials dispensed on a variety of products and the amount dispense, type of curing process (amine, platinum-cure, hygroscopic, etc.), and the cure time will affect the lifetime of the product. RTV sealants are usually robust in withstanding temperatures and vibration, BUT the issue is on the dispense side for having leak failures or inappropriate dispense locations. Changeovers increase the likelihood of the RTV pump failures and dispense head having multiple issues with weight dispensed and thickness of the bead. I can't count on my hands the number of times I saw dispense weights that were just wrong and caused scrap/defect at Visual Inspection (VI).

I knew some examples of this oil pan back for the Zenki generations saw the accumulation of the RTV near the edges of the oil pan. Guaranteed, if the Robot/Dispense gantry did not align itself to the dispense pattern for the BRZ/GR86 pan then you would see the accumulation of RTV on the interior of the oil pan or on the outer edge towards the screw holes. How much RTV you see dispensed in that strainer portion of the oil recirculation piping means the pattern REALLY got messed up from changeover, robot programming sequence, or just a dispense head malfunction. How that went through VI or QC means that Subaru will add some inspection for that dispense process now. 0km reviews are going to be a big discussion for Subaru if there are these examples of misplaced RTV.

They ought to go back to plain old paper or cork gaskets. They might leak but they never get sucked in to the oil pump.

lol I wish I still had pictures of some CNC welded large parts I had done where it wasn't set up correctly. A couple of the axis where indexed like 1/8" off, it was pretty funny.

Can you access the rear oil pan bolts without lifting the engine on these cars? Just did a KillerB oil pan swap on a 2019 STI last weekend and what a PITA, even though I've done it in the past.


To those talking about dropping the pan to inspect, I would try a boroscope the next time you do an oil change first. Might create more problems than you solve by dropping the pan yourself and having to reinstall with fresh gasket maker. There's an important sweet spot on how much sealant to use (obviously, given the topic of this thread).

no need to lift engine, dropping Pan requires dropping the OEM header. Simple job in a garage. Just need a 24hr cure.

The best consensus technique I believe is to spread the RTV with your fingers so that its a thin layer across the mating surface on the pan and not leave it beaded it up.

@Opie got told by Subaru that they were not selling short blocks and saving them for repair. Maybe they already knew something was up earlier this year.

Hey at least they're color coding the RTV to tell you where its from :)

drive it hard and document those oil changes! Bathtub failure curve baby

Could someone explain to me a few things regarding these pics/failures?

One, why do they all look like a coiled snake? Shouldn't they look like small and medium bits of random crap? I mean, I guess I can imagine that a HUGE bead would create overflow beads on both the inside and outside of the pan and that eventually it just all comes off at one time together (or slowly, over time, gets sucked into the intake in one piece). But in that case, shouldn't the tech see the excess on the outside of the pan and flag it?

So, are these cases where the robot puts the bead too far to the inside of the pan making the overflow bead almost entirely on the inside?

Second, why wouldn't the other four sides of the strainer provide enough flow to prevent catastrophic engine failure? Is it a case where 90% of the flow comes through the bottom/top of the strainer?

Or too much. In the case of the oil pan if the bead is squished out the whole chunk drops into the oil pan without getting chewed up by any moving parts. Here’s a crappy FIPG job done by a Toyota tech who “doesn’t build crap engines.”

…he built a crap engine.

https://uploads.tapatalk-cdn.com/202...b0b53f643e.jpg

The ridge where the pan sits will push any excess in more than out.
https://www.ft86club.com/forums/atta...1&d=1658269613

That stuff is actually very strong once set. if applied in a long section it will stay long so the "snake" if exactly what would be expected.

The strainer is meant to draw oil from all 5 sides but the main part is of course the center. Keep in mind that you don't have to complete eliminate the floe to cause issues just drop it below the critical level. Even just blocking the center and reducing flow by 60% (an out of my ass guess) could be enough to starve a bearing and send it spinning.

Ya that picture shows pretty clearly how the ridge will concentrate and then chop off any excessive or poorly placed sealant.

^^^this^^^ :cheers:

Dump me now, or love me long time.

My favorite example is the “cam lobe tickler.”

https://uploads.tapatalk-cdn.com/202...5aee750bf1.jpg

Oh that is a rare one. Usually only found in vending machines in dive bar washrooms.

I was due for an oil change so I poked my crappy old borescope in the pan. Plenty of excess RTV. Not as bad as that above example from the Toyota tech, but still.

Subaru is in for a rude awakening in the next year, going to be a lot of pissed off people needing new engines. How the heck did the factory fail this badly?


https://www.youtube.com/watch?v=oM5sdk1KRbY

Just my 2c - but I didn't read the question about tracking as an admonishment. As a fellow GR86 owner the same question occurred to me simply as a "how does their driving compare to mine" kind of thing. It's natural to assume that the harder it's driven the sooner the problems appear.

Maybe if it's sped up by driving hard it's slowed down by driving less. Part of me thinks the smart move is to flog it and try to get it to fail quickly so you get on the list for a new short block sooner, and part of me thinks the smart move is to keep the miles low and drive nicely so you get in on the (probable) recall repair and have the car OOC for a couple days instead of weeks/months.

The biggest difference between the two for me is just having to deal with another break-in period.

Oh, and to the question about why the bead comes off as one long snake - that's a function of the way the material is shaped. When you squish too-large a bead of sealant between two flat surfaces and create that rope/snake on the inside edge the weakest point is where it meets the part of itself that's squeezed between the two surfaces. You have a sealant gasket between those two parts that prevents leaking, and then you have fat bead attached to the inner edge that has a lot more strength and surface area than the rest. As fluid moves past it there's a small amount of force applied. If there's enough movement, or enough "rope" surface area to create enough force to begin to pull it away from the thinner "gasket" part of itself you begin to multiply the problem. A gap appears and that rope not has even more surface area and can be pulled into the deeper parts of the fluid current where there's more flowrate. This pulls more of the rope away from the gasket, which creates more drag/pull on the rope, and so on.

Basically, the snake/rope is practically perforated along that line, and easy to tear free at that point. It's not until it gets sucked into moving parts that it's likely to get chopped up.

I agree that driving it harder will definitely expose the problem sooner, if there was one to begin with. With a partial blocked pick up, the oil pressure might still be suffice to meet the demands of the low RPM operations. But that will not be the case for high RPM use. It can be a very slow death for someone who never flogs their car pending on how bad the block is.

I wonder if this will actually be a recall item. That is a lot of labor for something that "might" be a problem. I think TCOAT mentioned that this was a incident with the early 2013 cars, did they ever do a recall on then?

I agree completely and I had plans on tracking it, just hadn't had time yet. On the replacement motor or a car I plan to be on the rev limiter more, not less.

Also, I was on rev limiter or very close to it when the damage occurred.

IS this considered a design flaw?

Seems like they designed the sealant area with a very tight tolerance...which is usually ideal is it not?

I guess its just the nature of the sealant, just like in CPU's where you only need to place a dab of thermal past on the center of the CPU before placing the heatsink/fan, and not a whole goop covering the entire CPU....which actually performs worse for heat transfer.

Do you have confirmation for the demise of your engine? Blocked oil pick up? Or its still being investigated by the dealer?

Would blackstone oil check be able to verify that before a bigger failure?