My '14 Saga (head gasket or not)?

You can compare to post 892 in this thread as we had two Prii that were borescoped:

Possible Monthly install meets. Bay Area-Fremont | Page 45 | PriusChat

Is your car consuming coolant?

One way to know if you have a bad head gasket is if the coolant level drops.

Maybe put a mark on the reservoir at the current level and go from there.

 

Could be a head gasket for sure.

 

Yes. Well, maybe another mechanic. Because of this:

And this, very likely not necessary:

Gen 3 with 179K, EGR and intake manifold never been cleaned, it's very, very likely head gasket failure. There are countless tales here, where everything else is suspected first, everything else tried first. Leak-down test is the best way to check the head gasket integrity, see if it's leaking, and where.

I'd suspect the car was sold because of this condition; do you have any recourse, was it a dealership for example?

See first link in my signature, has EGR info. There's also links for head gasket replacement info.

The sand pounder: Toyota doesn't want to know about it...

 

Leakdown test or pressure-pulse sensor should verify the HG failure:

My opinion is that the HG and EGR issues are unrelated, but we can save that discussion for a different day. The coating just degrades on the HG. I've seen it on a few 2GR's too.

 

If it is not a vin number higher than this list you should consider new rings as well. Compare last six digits.

 

The production change upgrade started at 791355 so yours is the earlier less desirable design.

 

No help from dealer after 5 years 60k miles. Could have mechanic quote new pistons and rings especially if your head gasket job escalates to a replacement used engine. Main benefit is it eliminates oil consumption and excessive carbon buildup. Some of us believe it’s the root cause of head gasket issues by clogging up everything.

 

Make sure the inverter software update is installed. That is a dealer responsibility but they do not automatically do it.

If there are oil leaks at the timing chain cover, the head gasket repair should fix it. Some mechanics don't follow directions and end up with a leak again.

After getting your engine fixed, change oil every 5k miles or less. Even if Toyota says 10k miles is ok. Most agree that the 10k interval aggravated excessive oil consumption in these engines along with the design flaw in the piston rings.

 

Regarding the piston oil ring replacement: that is a BIG, separate job, requires complete engine removal, much additional labour expense. I would not dive into it, just because you're there.

And, as noted in the Technical Service Bulletin, you would want to have run-away oil consumption, to justify this. The criteria is a quart consumption, every 1100~1300 miles. The attachments show both the test and the ring replacement procedure.

If you for example are consuming only a pint or so between oil changes, that's not unusual for a higher mileage engine, really doesn't warrant intervention.

To check your oil consumption, the distance between the two dipstick marks represents 1.6 US quarts (1.5 litres). The marks are spaced roughly 1.5" apart, so each 1/2" is equiv. to 1 pint, aka 2 cups, aka 1/2 quart (roughly 0.5 litre). Attached is an excerpt from Owner's Manual, showing how to read the dipstick. Also attached are the two TS-B's relating to the oil consumption test and the remedy.

If I was in a high oil consumption situationa, and was going to undertake the oil ring change, I might just replace with the old styly rings, simply because it's less involved. Changing just the rings means you don't need to also change the pistons. This in itself is a saving in parts of maybe $200 USD, or more. Secondly, it's a lot simpler; the pistons don't need to be disassembled, just cleaned up. The old-style rings may be more problematic, but they're not bad, and should be good for at least another 100~150K miles.

 

Yeah not sure what to say; I'm by no means a mechanic, just piecing together info like lots here. You get the sense something feels different, could be a "slightly" bent piston arm, or maybe the damper between engine and transaxle?

 

This happened with the Prime when it was new too. Not all owners agreed that the switchover was an issue, but it was reported by several owners when there Primes were new, including me.
Things that made it worse for me were asking for heavy torque. Uphill climbs and especially in colder weather.
Much less noticeable when the ICE fired going downhill and at slower speeds as long as it wasn't uphill.
Hypermiling techniques like backing off the Go Pedal helped too. But is really hard backing off the Go Pedal while mounting a hill in traffic or on the highway.
Anything you can think of to reduce the shakes when they happen should make some difference in both the cars responsiveness and your sensitivity to the issue.

 

Good news! Don't forget about the EGR valve pipe and ducts that were cleaned. Since a buggered EGR system is thought to be the precursor to many head gasket issues. That's a lot of new data for the computers to adjust for.