IS IT A HEADGASKET?

Kind of wish the clean egr and misfire guys would back off and save unnecessary work and parts replacement. Many times that money would have paid somebody to change the hg at the early stage. Which is the time to clean the intake and egr.

98% an advanced stage hg. When it was rattling on cold start it was small, now you are risking hydrolock and bent rods.

A borescope inspection will remove the remaining 2% of doubt. Or just get a rebuilt engine that will also stop oil burning and save your $2k catalytic converter,

 

Depends on the rebuilder and his inspection after a teardown. I think the typical shop or diy rebuild is a risk. Many have bought from Hybridpit in Calif with good results and had it shipped to them.

These aluminum engines tolerate very little overheating without warping and have a tenacity to score the cylinder walls if it is an oil burner. Either problem and the engine may fail after a "simple" head gasket job. As a result most dealers and experienced mechanics would go straight to a professionally rebuilt engine unless the hg was caught early and the engine was not an oil burner.

The alternative is an used JDM engine installed by a shop who has done many gen3s. Again trust in the shop is essential. I would not install a US salvaged engine because the highest volume of gen3 engines were made prior to the late 2014 piston, hg and ring improvements.

Ideally find a non dealer shop who specializes in hybrids. Dealers are too expensive and will install a new short block to ensure success. Almost everyone else does not understand gen3 engines were a Toyota engineering fail. They often think gen3 misfires that clear up are plugs, egrs, coils and injectors.

A gen3 hg doesn't present the same as many are used to (a huge problem) and the egr guys give false hope after the damage has been done. This was initiated by a sticking egr tsb which caused stumbles and rough idles but not serious misfires.

 

Cleaning the EGR and intake at 160K miles, when you've got head gasket failure symptoms, is about 110K miles too late. Still commendable, but don't expect it to reverse time.

For head gasket diagnosis: pressurize the engine coolant circuit (employing something capable of applying pressure, maybe with an added T-connection to a hose at the reservoir), and use a boroscope to check for coolant tears (seeping past head gasket) and/or exceptionally clean-looking piston tops.

There's some relevant links in my signature; on a phone turn it landscape to see signatures.

The video sounds normal, btw. Was that a cold-start?

 

Doesn’t sound unusual at all then, but maybe the recording doesn’t do it justice. That said, 160k, it’s common.

 

the only way to determine if it is too late for just a hg is to disassemble it and measure everything.

 

yes, and they have to make sure no damage has been done to the lower half

 

Especially the bottom link.

There's flatness specs for the head/block interface, and the machined faces at intake and exaust manifolds IIRC. And the head bolts, timing chain, and so on. One biggie: with the head off, when you rotate the pistons to TDC (Top Dead Center), if any one of them is lower than the others, that's a sign of a bent piston arm.

Again, with 160K miles, and the sound in that video, it doesn't sound bad. Is coolant stable in the reservoir? Keep an eye on it over the next weeks.

 

Gen 4 transplants have proven problematic, prone to overheat, maybe not working well with gen 3 programming, or whatever.

Still, considering your miles, and the way that engine sounds in the video, I would lean towards just a gasket replacement. At least pull the head and check everything, see where you stand.

If you get the Toyota gasket kit it's got the head gasket plus pretty much every pliable seal, gasket, guide and O-ring in there. It's prudent to also replace the head bolts. It's about $200~250 USD for the kit, and maybe about $100 for new head bolts.

If you've got getting-up-there oil change, a short block swap is something to consider; they're about $2K brand new, and any for sale through official channels now will have the revised piston/rings, less prone to consumption. Either the old or new style are good for at least 100k anyway.

 

unfortunately, i have never had one done, or read about any in this area. there haven't been any decent hybrid shops recommended around here over the years that i have seen.
the only one i have read any decent review on is leo and sons. you can google them, i have no direct experience.
on the gen3/4 thing, i have read mixed reviews. all you can do is read the threads, and if you can find someone to do the work, they will have an opinion i'm sure.

 

It'd take me a bit longer.

Full disclosure: I've never done anything more arduous than the EGR cleanout.

I wouldn't recommend these guys, but a good video:

For the head bolts they use a "triple square" bit, which is not optimum. Toyota specs a "10 mm double hex", which is readily available on amazon. Also, they use an alternative form-in-place gasket, Permatex Ultra-Black IIRC (it's spec'd in the video), which likely IS preferable to the Toyota spec: it's got a much more leisurely cure-time, which is important for DIY install of the timing chain cover.

 

i think you would have to take it to a machine shop to determine. you also need to make sure the top of the block is flat.
again, without testing, idk if the engine is sound outside of the head gasket.
rjparker suggests some testing in his post above, he knows more than i do.