Full on intake, egr, throttle cleaning

See attached Repair Manual excerpt for engine coolant change (attached inverter coolant change as well, just in case). It suggests to open the spigot on the block, drain that as well. That I wouldn't bother with: in practice I found maybe a quarter cup drain from there, at most, and it's very hard to reach.

Having a '10, it likely has the vent at top of engine coolant circuit, white capped gizmo at junction of hoses above EGR components. I'd leave that open while refilling, till coolant starts flowing out (you can attach tube to it to avoid spill if you want).

The instruction recommends to fill to the B line on reservoir, cap it securely, and run car in maintenance mode (info attached) till fans come on. When doing ours, I ran it in maintenance mode for about 30 minutes, fan never came on, I finally shut it down, and that worked out.

See first two links in my signature. On a phone turn it landscape to see signature.

160K is a little late in the day to start in on this. Ideally I would clean the EGR every 50K. 160K is definitely into head gasket failure territory; I would keep that in mind.

Are you consuming oil? If so, at what rate?

My 2 cents: the head gaskets are blowing due to EGR components hopelessly clogged with carbon. This happens even with an engine without runaway oil consumption, likely starting when the cars roll out of the factory. It's a lousy EGR design, largely rectified with gen 4. Then gen 4's started blowing head gaskets due to coolant loss, due to coolant leakage in the Exhaust Heat Recovery system.

Where is Samsara btw? I see one in Spain, another in India.

 

For a responders geographic location is of more interest, things like where you might be buying supplies, if there's Toyota dealerships, whatever.

 

Not sure; they may loosen up piston rings. What's your rate of oil consumption?

 

I can't imagine how fuel injector cleaner would unstick piston rings. Stranger things have happened but that seems like an outlandish thing to expect. Usually it only cleans deposits in the fuel injectors themselves, since it doesn't really spend any time in the combustion chamber before it is exploding. And even the cleaning of the fuel injectors is extremely suspect since you dilute it so much with gasoline.

FWIW, when you take your car in for a fuel system cleaning at the dealer, they literally hook the fuel rail up to a can of this (or whatever fuel system cleaner they have on the shelf) and idle the motor exclusively on fuel system cleaner until the can is empty. So even putting this in a tank of gas on E will still be diluting it 10-20 parts gas to one part cleaner.

 

I’d focus on the EGR and intake first, and just monitor oil consumption.

 

I have seen shops that use a fancy ultrasonic cleaner to remove deposits on 20 year old injectors. Those shops also have a flow bench to measure how much improvement the cleaning nets in terms of flow rate and evenness from one injector to the next. We are talking in the ballpark of 5% difference from one to the next though, not significant stuff.

Remember that gasoline is a really great solvent. So whatever buildup you might see in the fuel system can only be something #1 already in the gas tank, and #2 not soluble in gas. That is why you don't normally see fuel injector problems even in old cars.

And the problem you see, if you did experience buildup, it would not be because of a restriction; remember that the car normally runs in an O2 feedback control loop. If the O2 sensors detect a lean or a rich condition, the ECU will adjust for it and add or subtract fuel as necessary to hit stoich. The only danger is extreme unevenness from one cylinder to the next. If all four clog up but do it evenly, the ECU can take care of it. But if one clogs up then that cylinder will run lean. Either way it probably won't cause an MPG issue.

Putting fuel system cleaners in the tank, in my opinion, are hogwash. Though, that opinion is worth exactly what you paid for it. That all make any sense?

 

An example of before/after test results from such an on-the-bench injector service can be seen in this post. That was in a car that was running quite poorly before, and ran well after. You can see in those results that there was an overall reduction of flow that exceeded the ±20% the car's ECM can trim for, and also a 30+% relative flow difference between the best and worst injector, leading to very rough running.

So, injectors can get bad like that. They can also, in other cars, go for years and years and years and pass such a test with flying colors. The exercise is probably worthwhile chiefly when there is some reason for suspecting the injectors might be bad.

 

Yes, but there was some kind of extenuating circumstances for that car - you don't see cars with 165k miles having those kinds of problems virtually ever. If it was some kind of buildup that gradually increased for every car, you'd see cars like this more often, especially high mileage cars. I assume there was bad gas involved or some kind of failure of the integrity of the fuel tank (perhaps rust). Also as you noted, it was not fixed by multiple rounds of fuel system cleaner.

 

That last part did seem to be one of the takeaways from the experience: the in-tank cleaners did not seem to be effective on injectors with actual problems (though on-the-bench cleaning restored them like new). That was also a conclusion of the article linked in that linked post.

It's possible the in-tank cleaners have some effect in keeping good injectors from getting bad in the first place; I don't know. I'm hoping the additive package in "top tier" fuel is generally enough to do that job.

It's clear that not every car inevitably develops injector issues, but that some do sometimes. I'm not really qualified to pronounce on why those did when the rest didn't.

 

Geez, I also did both those, at the same time, well log shows same day. I believe I drained and filled the engine first. Then started on the inverter.

@ChapmanF might have some ideas: scenario is BOTH coolant circuits are drained, how to proceed.

 

The effect of maintenance mode is to keep the engine running so you can get it fully warmed up without having it turn off when it normally would.

Maintenance mode doesn't change anything about the inverter cooling system, so that pump will circulate inverter coolant just as well in maintenance mode as out.

Make sure you've got a good initial fill in both systems before going to READY at all. The engine cooling system will then pretty much take care of itself; if you started at the B line and capped the reservoir as instructed, the extra coolant should trade places with the trapped air and be down to FULL after you have warmed it all up and then let it cool.

The inverter coolant level will drop while the pump is circulating it and the air escapes, and you'll have to keep an eye on that to add more if needed before it gets too low and sucks air (go back to start, do not collect $200).

If you had a scan tool with active tests, you wouldn't go to READY for the inverter coolant; you'd just go to IG ON and use the scan tool to command the inverter pump on. That has the advantage that the inverter itself isn't trying to operate, as it would be in READY mode.