An FA20D failure / diagnosis & repair story...
 

So in September of '21 I picked up a clean title, 52,856 mile 2013 FRS that had rod-knock, it was car #16 on the Opie & Dave-RoR's rebuild page. Car ran when we got it, drove it up on my trailer, and then off & into my garage. We swapped in a good motor and sold the car...the engine we took out has been sitting in my garage ever since.

After almost 3 years of my wife asking why it was still in the garage and what I was going to do with it...I decided to pull it apart and see how bad the damage really was. Story from the previous owner was that the car had the valve spring recall done and shortly thereafter it started knocking so he stopped driving it and got a new car. The paperwork in the car confirmed the recall, clutch and an oil change had been done at 41,238 miles at a local Toyota dealer. When I recieved the car, it still had the OEM Toyota oil filter on it. Looked to me like the owner went 9,000+ miles without an oil change in addition to whatever we might find inside the engine that "might" be caused by the recall work.

So yesterday, I rolled the engine out of its hibernation spot, SuperClean & pressure washed it off and started tearing it down...here is what I found...it is not pretty.

Removed crank pulley, water pump & pully and pulled front timing cover. Then removed the lower oil pan.

Pic#3: Removed Oil pan and found that the Oil Pickup was 99% plugged with RTV. This likely occurred during the valve spring recall when the tech failed to block the passages to the oil pan and allowed the old RTV from the timing cover surfacesxo fall into the pan when cleaning the surfaces before resealing.

Removed thermostat and upper oil pan assembly, here I can see the connecting rods, checked each one for play, only cylinder #3 has play...that's the knocking.

Pic #4: Removed valve covers for inspection, now that I know oil starvation is an issue there are other things to check. First the cam lobes for galling, no damage found.

Pic# 5: Then removed the cam caps from the carriers, uh oh. First oil starvation damage found. Cam shafts are galled from lack of lubrication...also found the ham fisted tech that performed the recall gouged the crap out of the cam carrier sealing surface.

Removed both heads. Head gaskets look great...

Pic #6: Pulled all of the pistons and connecting rods from the block. As noted, #3 was the knocker. The remaining bearings looked ok. Crankshaft is seriously galled at Cyl #3.

So this is where I stopped to add up the minimum parts I'd need if I chose to rebuild it:
Engine Gasket Set - 1
CrankShaft - 1
Connecting Rod - 1
Main Bearing Set - 1
Rod Bearing Set - 1
Cam Carrier Assembly* - 1L & 1R
Camshafts - All 4
Oil Pickup/Strainer - 1
Piston Ring Set* - 1
Retail parts cost.....$3,636.62
Astericks are parts that could potentially be reused...but I wouldn't feel comfortable. Plus there are many other parts that may need attention...pretty much anything that oil touches, oil pump, chain tensioners, VVT sprockets...

This is why a finding a used engine is the preferred solution....

Conclusion: shoddy workmanship definitly caused this engine's early demise. Improper cleaning, wrong sealant, too much sealant...of course the owners negligent maintenance certainly didn't help the situation....

So what is next for this engine? Not sure...maybe I'll complete the rebuild. Anyone got a good set of cams, or crankshaft? Either way I'll likely keep all the good parts...

Small update, local machine shop says that if the camshaft and carrier damage is light enough, they may be able to micropolish those surfaces. Since I can only barely feel them with my fingernail, going to drop them off tommorow to be evaluated...if they can be salvaged, thats about 40% of the parts cost...we'll see.

I'm always concerned about mitigating any contamination. Once upon a time I spent big bucks getting a crank ground and plated. Too bad the oil passage wasn't cleaned properly. I should've double checked it before assembly but didn't and the motor lasted a week. I'm impressed with your knowledge of these cars.

Rebuilding engines is like paint work, the prep is the most important part. If rebuilt every oil passage, in-block filter, VVT sprockets, Oil pump gears, etc will be cleaned multiple times. Will likely also put a magentic drain plug in it and change the oil & filter after running up to operating temp. Can't be too careful....

Good news, machine shop says they can micropolish the cams and carriers. Should have them back in a few days.

Well these look better...

^^^ this ^^^

I'm sure it'll be like new or better when you're finished.

If I was going as far as to rebuild one of these, especially for track use, I’d want to line bore the cases and size the mains. I have a 13’ long block in my shop that’s the same deal I may get to one day. I had priced this out a few times and a OE short block or a used engine is a far better deal then rebuilding. Even a built short block doesn’t pencil to bad in comparison.

Crank is being replaced, mains will be measured before assembly to see if any further work is needed. Then will get new bearings (main & rod) upon final assembly. I'm doubting line boring will be needed, but the specs will tell...

I don't disagree with that. It's just that if I am building another engine for myself, I would probably go the extra mile and have them checked if not just done.

There are precious few useful parts in one of these engines after a blow up! I had similar issues, I had to strip 3 engines to find enough usable parts to do a rebuild. Fortunately one was a crash damaged engine and still had a good crank.
I had lot of trouble getting main bearing clearances right. I bought 3 sets of main bearings (2xACL std and 1xACL 0.001 undersize) and with a lot of careful measuring I mix-and-matched a set that had the correct clearances.

Split the block, did a little cam carrier cleaning and replaced the #3 connecting rod. Main bearings won't arrive until Jan 31st...so doing little bits as I can...did I mention how awesome the cams came out....lol

Hone and re-ring?

13 feet, that *is* a LONG block!

I’m always compensating.

I'd say that's overcompensating.

Realized that I actually had the main bearings, it was the rod bearing that have not arrived, so I got the block halves cleaned out and cylinders honed, installed the main bearings, checked tolerances, all journals were in spec so went ahead and assembly lubed the crankshaft and reassembled the partial short block. Yes, I still need to install the rear main seal...

Then got to work installing the left-side cams in the carrier and reassembling them. Temporarily bolted them the cylinder head to keep the rockers in place, so it is ready to go. Started on the right-side head, removed cams, carriers and rocker parts. Started cleaning them up. Dropped those right-side cams and carriers off at the machine shop this morning to be polished like the left ones. I’ll get them back tomorrow or Sat

Still waiting on rod bearings to install the pistons and new rings. Going to clean all the carbon off the pistons once I get the cams & carriers back from the machine shop. May start cleaning the RTV off the timing cover & oil pans today…

Found out the engine gasket set did not include the cam carrier screen filters, so headed to the dealer after lunch to pick those up and a set of spark plugs.

Did you disassemble and clean the cam phasers? You might need them clean in case you meet some Klingons.

I had the machine shop do that for me as they had to remove them to polish the cams. And at $50 per pair of cams for all of that, it was worth it to me!

Installed the rear main seal yesterday, also went to the dealer and picked up the cam carrier filter screens and a set of plugs. Machine shop got the cams & carriers done in a few hours, picked them up yesterday afternoon so I went ahead and assembled them, and temporarily installed on the cylinder head to keep the rockers in place. Right side is now also ready to be reinstalled.

Also got all the RTV off the upper oil pan and started on the front timing cover. Going to dissassemble the oil pump and passages to clean them out as well.

So far I've used a 1.5 cans of Subaru's Silicone gasket remover, probably 15 regular razor blades and 30+ plastic razor blades to get the RTV off....there is A LOT, like really a lot...everywhere. This stuff works great once you've gotten the thick parts off. Getting to the point where there are just small things I can do until the rod bearings show up....

New parts purchased so far for a little over $1,100:
Engine Gasket Set (OEM)
Crankshaft (OEM)
Connecting Rod (OEM)
Strainer/Oil Pickup (OEM)
PCV Connector (OEM)
4 Spark Plugs (OEM)
4 Screen filters (OEM)
Set of Rings (OEM)
Block halve O-ring (OEM)
Main Beaings (King Racing)
Rod Bearings (King Racing)

While the Engine gasket set is the best, most cost efficient way to buy most of the gaskets you would need, it is missing a few things to be aware of...here are the things I know I will need but are not included in the kit, some have already been bought, some I'll buy as I get closer to installing them:
Cam Carrier Screen filters (4)
O-ring between block halves (1)
O-ring for strainer/oil pickup (1)
Lower oil pan seals (2)
I'm sure there will be a few more....
Injector seals (port & direct)

BTW, Dawn Powerwash Dish Spray works great to clean aluminum parts...

Holy crap these cleaned up nice, 2 done, 2 to go.

Have you thought about porting the oil passages in the timing cover?

Don’t forget head bolts. I am waiting on them since I forgot to order them.

Not at all, really don't see this as a big need. And if done wrong could lead to pressure issues elsewhere.




Per the Subaru manual, the Cylinder Head bolts are reuseable. The connecting rod bolts however, are not...those have been ordered.


As I continue to wait on the rod bearings...I think I've now done all I can do until they arrive (expected on Wed Jan 31st). Today I finsished cleaning everything. Including the oil pump. Got all the old debris out of the engine. Then reinstalled all the sensors and front seal on the front timing cover. Installed the lower oil pan to the upper oil pan, Installed the thermostat houseing and thermostat with a new gasket. Realized that I need a new water pump gasket...so that will be picked up shortly. It should be a quick reassembly once the rod bearings arrive...

Why did we not see a single pic of the crankshaft? I am disappoint.

Doh :slap:

Didn’t realize that. I’m doing new ones anyway since the engine I am putting together will be for boost.

The damaged one? Here it is...

Why always #3? Grrr...

Rod 1 is fed from 1st main bearing. Rod 4 is fed from 5th main bearing. Rods 2 and 3 are both fed from 3rd main bearing. It will always be 2 or 3 rod that fails first as they have to share oil.

Just guessing... Maybe the angled rod cap has something to do with it? The angle is different relative to rotation on 2 and 3 rods. When the oil disappears, maybe one orientation is more survivable than the other.

On a regular inline crank it is common for each rod to have its own feed from a main bearing, no sharing.

Well....now I know where this engine will be going once I finish rebuilding it....no accidents, hydrolocked motor!

solidsnake had a couple theories on it. I know he was slotting bearings and opening up feeds on the crank.

I remember some of his stuff. One was the parting line and taper for the mains oil gallery. I didn't quite understand his work on the crank. Wish he hadn't thrown that tantrum and deleted all of it. :(

Yeah, I still have some PM’s from him from 19’ for reference but none of it in what exactly he was doing.

Rod bearings and rings arrived today, so I started to install the pistons...got to #3, and as I was removing the old rings, part of the ringlang came with it...WTF? I guess it was cracked and being held together with the rings still installed. So now, 1 piston on order....meanwhile I did get the other three rods plastiguaged, all in spec. So three of the 4 pistons are installed. Think I can get the head installed on the side that has two while I wait on more parts...

Interesting result from the harsh vibration. I wonder how long it was operated with that spun bearing. Like you noticed, that rod end got hot!

Where I'm at...

And it looks like you can't buy pistons seperately, they come in a set for one side of the engine...so I'll be getting 2 right side "B" pistons....guess I'll have a spare...

Good opportunity to put a decent set of rods in there. The stock rods are made of chocolate. There's some pretty good value aftermarket stuff around these days.
With a good set of rods it'll be ready for whatever you can throw at it in the future.

I was thinking the same thing. Remove the one major weak link standing in the way of forced induction just in case. Or at least make it that much more reliable for the future if you want to stay au naturale.

So's the gearbox. Leave it stock.

Besides, he's rescuing/flipping these. :bow:

New piston finally arrived, got it installed and completed the engine today. Tomorrow I'll pull the bad motor out of the White #19 and by Sunday afternoon the rebuilt motor should be fully installed and running in it. Then I'll tear down that one...