2011 with 280k miles, do the water pump?

Any car could have problems, and do. It's hard to know the history.
Even car fax has been screwing up. I wouldn't trust them more than anyone else.
A clogged cooler could cause more back pressure by not allowing the exhaust gasses
to exit completely and creating more pressure in the cylinder which would cause more
pressure on the head gasket....
I'm sure there are several reasons the gasket goes.....

Push comes to shove, replace the head gasket, water pump impeller, inverter pump.....
Have everything tested and then hope for the best. As you would with any used vehicle.

 

The engine's have a VIN plate, around back, near the passenger end. @rjparker might have an pic.

Dealerships will deal with it, for about a grand USD for parts alone, before they start talking about labour.

Toyota, they did have a warranty extension for the EGR system (in Canada, my letter is dated May 2017, and id'd as SOSH-W11-1A). They talk about "rough idle and/or tapping noise from the HV transaxle at cold start due to a sticking EGR valve due to excess carbon build-up". Rough idle at cold start is a typical head gasket failure symtom, due to incompressible coolant in a combustion chamber.

They also say "the majority of vehicles will not experience this condition" (underlined and italicized, just like that. And who knows your car better, right?

When 4th gen came out I recall one of the press releases touted "revised EGR system". Oddly technical?

 

Agree 100% based on experience at high miles. Also agree with the strategy to clean an egr cooler.

The Toyota concerns have to do with an egr flowing when it should not. Like at low speed engine operation. Same as every other egr system. Egr valve sticking open. Cleaning a clogged system will resolve a check engine and restore the egr engine tune. Having a check engine light on all the time makes it harder to know when something else fails.

Vin plate (if not removed by the salvage yard or non-existent on a JDM salvage engine from Japanese use)

 

Back in the 80s I knew all the first seven of the vins of all vehicles we cared for corolla's celica's hi lux trucks lancruiser supra .still do today still own 85 celica's n supras and GT-s.

 

If you notice, this warranty extension covers the EGR valve. No mention of the EGR cooler or the intake manifold. Also, a stuck open EGR valve can absolutely cause a rough idle.

4th Gen high mileage cars are now experiencing blown head gaskets, even with an EGR system that doesn't clog. More proof that the EGR system has no correlation to head gasket life.

 

So if OP's engine doesn't have a plate, or it's got a plate with a different VIN, it's not the engine that came with the car from the factory?

 

This is from what, Gasket Masters?

Here, any 4th gen with blown head gaskets have turned out to be neglected coolant levels, due to exhaust heat recovery system leaking.

 

Does the Prime have the exhaust heat recovery system?


iPhone ? Pro

 

I believe all 3rd and 4th gen, plug-ins included.

 

They really should have a low coolant level sensor in the overflow tank. Waiting till an overheat alert is too late.


iPhone ? Pro

 

Yes.

No vin plate is normal from salvage yards. Reduces embarrassing inquiries about the actual year, miles or chop shop source. Different vin from the car means it was changed.

 

If you do the water pump you should also do the thermostat since its right on the other side of the pump housing and you will have drained the fluid.

SM-G960U ?

 

Don't forget to clean out the intake manifold's EGR passages, too. That's easier than doing the cooler, and equally or more likely to create havoc if neglected too long.