310,000 Mile 2AZ-FE Innards

When I noticed the oil on the exhaust heat shield, I immediately purchased the valve cover gasket and pcv valve because that amount of oil certainly says pushed gasket rather than just bad gasket. It's still hard to say which one was the root cause though. All the hold down bolts for the valve cover were pretty loose. The rubber properties of the original gasket were almost entirely cooked out of it. The valve cover gasket in the front above the exhaust manifold could be broken like glass. The pcv valve I took out was only slightly gummy by the sounds of the rattle but it certainly wasn't stopped up. I think the gasket broke because it was brittle and had no elasticity left to provide pressure to keep the hardware tight and not because I was building any kind of abnormal crankcase pressures.

I'm sure the engine has more blowby than when it was new but I can say that it doesn't show any signs of being excessive in any way. I haven't done a leak down test but I can offer a lot of anecdotal info which points towards the engine being a darn good shape

Oil consumption has remained consistent since it was brought home from the dealer, If it had a lot of blowby I would expect that consumption to increase over time.

Long term fuel trim is surprisingly low (as in close to zero correction) this tells me that no huge changes in compression or engine efficiency have occurred over its lifetime. Still idles with excellent vacuum and the pcv valve I just replaced was original to the engine, never been cleaned because it hasn't needed it.

It hasn't lost any power noticeably since it's been brand new. Trust me if someone needs to be passed going down the road the pedal is to the wood, we use the whole rev range on a regular basis which I think is good for engines.
I was going to ask if the bolts were loose, but figured it would come up in the conversation. It seemed to me that the gasket was pushed out as well, so that's why I suggested checking all parts of the PCV system, such as any hoses, elbows or fittings.
 
I was going to ask if the bolts were loose, but figured it would come up in the conversation. It seemed to me that the gasket was pushed out as well, so that's why I suggested checking all parts of the PCV system, such as any hoses, elbows or fittings.
PCV system is flowing freely. When I fired the engine up after getting everything buttoned back up I noticed a new noise, kind of a static type of sound from the top of the engine. It was noise coming from the new pcv valve. I pulled the hose and it immediately died from sucking air and going lean. The system is flowing freely and the pcv is doing what it's supposed to do
 
Here's the 2AZ-FE in 05 Scion tC:

180k.JPG


My valve cover gasket started seeping around 180k. The cover was cleaned before the picture was taken.
 
My mom bought this car brand new, I did all the maintenance on it from the start. I bought the car from my mom in 2018. If you take a look at the numbers you can see that it gets quite a few miles put on it each year, therefore the time between 5k oil changes is not long.

Because of the usage cycle the engine being short-tripped isn't the typical case, which I think is a huge contributor for the lack of excessive oil consumption and the long life of a lot of the components.
Thank you.

I asked those questions, while acknowledging the defective design of the low tension rings, always thought a shorter oci from new was the way to avoid these issues.

I guess oil or chemicals really cant fix bad design
 
a great reliability record + of course YOUR upkeep helps!! todays cars being more complicated usually means MORE costly repairs!!
 
Started the wife's beater tonight, 2007 Camry, 2AZ-FE, 310,000 miles and smelled some burned oil inside the car, popped the hood and found a nice little surprise sitting on top of the exhaust manifold heat guardView attachment 199401

Darn I guess the valve cover gasket has finally given up. As you can see it has been seeping for a long time but hasn't been creating any burned oil smell until tonight. I guess I'll be starting this project on a cold minnesota night

Here's the gasket, as far as I know it is original and it split on the front side right by the exhaust manifold which i'm sure is the typical failure mode. The whole front side of this gasket could be broken like glass it was so brittle, as well as the spark plug seals

View attachment 199402

I've posted about this car a few times since I have more or less maintained it since it has been brand new. It's never been victim of the notorious oil burning plague that infects many of the early 2az-fe's. This one has burned a quart of oil every 5000 miles since day one, and still to this day.

Oil changes have always been performed at 5000 miles using M1 0w20 AFE

here's how the valve cover and valve train looks after 310,000 and never being touched until a couple hours ago
View attachment 199403

View attachment 199404

Figured that i'd post some pictures since everyone seems to like internal engine pics

Also replaced the PCV valve, it still rattled a tad but you could tell it was a little gummy inside. PCV valve has never been touched either until tonight.
It looks like it’s ready for another 300k. Hopefully the rest of the engine is in the same condition. Nice!🙂
 
I think it’s pretty dirty for 5k oci’s and Mobil 1.
For an engine family with a history of massive oil consumption (which his isn't experiencing)? Other than the build-up on the valve cover, I think the head itself looks very good, given the application.
 
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