10K oil changes are BAD! ??

Thank you for sharing and everything you’ve posted on this board.

Part of the reason I am reluctant would be my OCD on having things the way they are supposed to be. (Not sure if you’d remember but I took maybe a month to disassemble the lower front subframe to correct a little alignment caster issue. If it didn’t work I would have torn the whole thing down again to correct it! Luckily it realized that I would and behaved! ) I would be so irritated with a missing lower bolt/stud and probably spend (up to a month) to get it back on just right.

But anyways my goal here is the same just to share what happens, and to hopefully help the OP in the right direction.

There’s a no start condition that is supposedly the Toyota (T-SB) solution of updated intake manifold (ending -90 or -91). There is also an updated EGR T-SB for COLD weather rattle). Along with these two are some programming. I have the programming done but not the manifold nor the new EGR. Why? Didn’t want to spend the money on stuff when our car is subject to moderate So Cal weather).

So far so good. I’m allowed to use the car less because supposedly the LiFePO4 12V doesn’t actually respond well to being topped off constantly so driving less is probably better for it than driving it all the time. Yes it fits the COVID “lifestyle” as well….

 

Is there any empirical evidence that Toyota's "upgraded" Gen 3 intake manifold (plus software update) actually improves the intake manifold EGR clogging issue?

 

I'm not positive that's what the manifold revision was even intended to do.

I think the best information we got here was that the way they changed the shape of the EGR passages was to make it less likely that the engine gets a snort of condensed water at startup out of those passages, when the weather conditions tend that way.

That was kind of an unrelated problem, but one that a lot of new owners of the first Gen 3s were discussing here as soon as their first year of ownership. It wasn't something like EGR clogging or head gasket issues that started appearing on the radar after some time and miles had passed.

 

This won't stop the knocking people have.
And there is an anti know sensor that prevents that from happening.
Unless the quality of fuel is really horrible.

 

I’m sorry I stated that the T-SB was specifically for no start in some extremely cold weather. Below anywhere we would get here in a Los Angeles suburb. (Hence why I didn’t replace it). Whether it solves the EGR clogging well a brand spanking new intake manifold is not gonna gonna have any restriction.

Whether you doubt Toyota’s EGR TS-B I can only repeat what I remember because I’ve lost it…. Don’t kill the messenger. I still clearly remember instruction to unwrap a portion of the harness so it can reach the new plug on the redesign. That one I was planning on buying but I wanted a Dorman unit with a lifetime warranty. (I have no clue if it’s a redesign so I held off).

 

Thank you for the warning. That’s definitely a bummer.

 

If you disable the EGR system, that's the same as having a clogged EGR system, which Mendel says will take out the head gasket (which I don't believe, by the way).

 

If you block the EGR flow completely, whatever way you do it, the car will eventually catch on because of its regularly-scheduled flow test, and post a P0401 code. Once it does that, it will protectively dial back engine performance parameters like spark timing.

Any risks of head gasket or other damage will be highest in the interim period while you have the flow blocked but the ECM hasn't caught on yet. (Or any time you have cleared the P0401 code, and the ECM hasn't re-posted it yet.)

 

Just for the record, I would never consider blocking the EGR system. I like my vehicles to be as clean and efficient as possible.

But, I thought the theory was the mismatched EGR flow is what may cause 'something' to happen in cylinders 1 and 2.
Those first two ports are found blocked the most because the EGR gasses are cooling off as they move across the cool manifold, correct?
Whereas with the EGR system totally blocked with a plate, there would be no 'mismatch'.
Just keeping the discussion going.

Is there any indication of the Gen 4 engine having a design change with the head gasket system?

 

Huh, I do not really agree with not expensive. Here in Europe is 110 EUR for two cans.
In comparison I bought a QUALITY coolant for my Audi A2 and it cost 30 EUR. Yes, the quantity was half of it, but anyway, the same quantity would cost 60 EUR.
I will just keep my recomended schedule in the service book. And I always keep an eye that the coolant is clean. And both were after 90.000 miles.

 

I might be able to come up with them.

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Didn't take pics of actual bearings but here is the crankshaft, view into the cylinders from underneath, and where the head gasket was blown out

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Yeah you could have gone into my posts if you want to doubt my word. Try working for your information.

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Oh wait you can see the pristine main bearings in there.

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Now what ye of little faith? Pictures provided. I would say put some carbon cleaner in the oil once in a while before the oil change. Because rings weren't stuck but could have been cleaner

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You didn't replace the pistons and rings with the updated one?
Just cleaning up the piston ring area of the pistons?

 

New. I was commenting on maintaining during operation.
Kinda silly to strip it down to the bare block and not replace the rings. Honed the cylinders and lapped the valves.

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So you DID put the 2015 piston and rings in....
It should last a longggg time then.

 

Even the old-style piston rings would give you a long reprieve, say at least 100K miles. Maybe more so if you stick with 5k mile oil change. It's less expense and hassle; pistons can stay.

 

Don't know but when I pulled it apart again the rings were no good.

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