sudden coolant consumption, options to prevent HG failure?

Blown head gaskets

 

What was the condition of the EGR cooler when you cleaned it at 110k, can you hazard a clogging percentage? Also, did you clean the intake manifold, in particular the small EGR passages at each port?

Test the head gasket integrity with a leak down test? Toyota makes a gasket kit, includes head gasket and pretty much everything. A lot replace the head bolts too, for just in case.

I would pass on those AC Delco tabs.

 

Lets see, maybe a spreadsheet is needed to count the number of gen3 head gaskets. About ten in the last month that I know of which is a very small sample set. Maybe there is a systemic fault....

Jack, where are you located? One of our diy guys did a headgasket for $156 in parts, Gasketmasters in Cali, $1500-$2000 with a reworked head, some this month have replaced the engine from $1800 - $3500. Dealers will offer an engine for $5000 - $7000.

 

The downside of waiting can be a bent rod or even a hole in the block, both caused by a hydrolock of coolant in the cylinder.

watch this video

 

Hi Jack, what part of the USA are you from?

 

That is a GM solution I swear by on an HT4100 engine. (See Cadillac Forums in the '85 de Ville FWD section. Quite controversial, I swear by it that it stops water pump failures in that engine. GM put warning labels on cover on top of the radiator with the part number of those tabs). GM apparently sent out TSBs that it was no longer required, but I still have that whole package in our system.

If you're burning coolant, (coolant into exhaust) there is a product specifically for that which is worth a shot called K-Seal. Have that in another car. Follow directions carefully.



moto g(7) power ?

 

Welp I disagree with just about everything you said:

1. The stop-leak quick fix
2. "Thermal cycling"
3. Toyota head gasket quality
4. You're good for 200K if you drive highway

Nope, not just about, it's everything, lol.

 

Fair enough:

1. The stop-leak quick fix <buys you nothing but a month or two, makes a royal mess of the coolant system
2. "Thermal cycling" <Gasket Master's theory, while the smoking gun is a carbon chocked EGR. Their expertise is replacing head gaskets fast/cheap. Even they say in one video "it's always cylinder one". Wonder why... Thermal expansion? Or that's the cylinder one EGR port is the one that clogs worst and first.
3. Toyota head gasket quality <Likely the best head gasket going.
4. You're good for 200K if you drive highway <Seriously doubt it. If anything, the protracted high speed will accelerated the EGR clogging.

 

You're correct. There are plug in prius owners that posted on this gen 3 non-PIP forum intentionally seeking head gasket failure explanations and/or quick fixes when they are running on electric most of the time. Thermal cycling rarely happens on PIP gen 3 but they still suffer blown head gasket failure under 100,000 miles, one came here lurking with 50,000 miles w/gasket failure. I'll ignore myself also

 

Very useful explanations, but still unfriendly

 

Terse, terse.

 

I think OP's data point isn't conclusive but can't be ignored -- an early head gasket failure that happened well after a full EGR cleaning really is notable. It runs counter to the most popular theory about what's causing the HG failures. Not sure if we've seen this happen before, discounting where people do an emergency EGR clean *after* things start running rough.

We can still all agree that there's *something* wrong with Toyota's design on the Gen 3 Prius that is leading to low-mileage head gasket failures, and not much right with Toyota's public response to whatever that problem is. (Right?)

That idea of a spreadsheet tracking early head gasket failures is a great one IMO. Especially if it includes the manufacture date and location. (Hey I'm not volunteering tho!) I seem to remember there was a recall for head gasket issues on a short run of serials from one factory, it would be interesting to see how many of the observed failures were close to those.

From the horror stories I've seen in these forums, those stop-leak products don't seem to play well with this car. If it's really the HG (check cylinders in morning for fluid, or find a guy who's good at leak-down testing), it's a matter of time before you replace the HG or end up needing an engine rebuild. The stop-leak thing is a seductive temptation, but the fact that you already had a rough start is a huge red flag. And I'm not talking about a one with a friendly maple leaf.