09 Touring sheds heat better than any mecha

A head gasket being slightly broken is a lot like being slightly pregnant. After a short time the morning after pill does not work and neither does block sealer. Then you have a new baby or a new engine.

If the fans don't engage in ac mode they are suffering as well. Check power at the fan connector.

 

And head gasket sealer is like a PayDay Loan place?

 

If you can open the radiator with the temp at 245 - and the radiator hoses are cool - you're probably running with very little water (coolant) in the system and that engine is not gonna last much longer.

With no pressure in the system (can take cap off without being boiled alive), plain old water in the system (boiling point of 212F at sea level) AND the gauge showing 245 - there is no liquid water cooling the engine.

No "antifreeze"/glycol in the system and no pressure means you have nothing to raise the boiling point of water.

If you keep driving it without doing a proper repair, and filling the cooling system with proper coolant - you may as well just drive it to the junkyard.

A Geena Davis might say "Be afraid, Be very afraid."

 

Can they use ultrasound to tell you which it's going to be?

 

Nah - but you could use a borescope to tell you which cylinder was gonna give you labor pains.....

 

Nope.

A payday loan place provides a valuable (but expensive) service to people with few options.

Head gasket sealer is more like an old condom - it might promise to protect you - but will likely not provide any service.

 

...evidence that somebody got f----d?

Jerome- Please understand this joke wasn't meant as a personal attack against you. I understand that a broken car can be a rough experience, been there myself.

My own experience is that gasket sealer gets you home once. It usually isn't good enough to allow you to keep driving in a normal sense, not over any real span of time anyway.

It's time to start working on plan b.

 

I know there are plenty of products that claim to seal head gaskets, but if you consider the pressures involved, if it even gets you home once - you're fortunate. Consider too that those pressures have already succeeded in blowing through a gasket that was much better suited to the task than any "pour this in your engine" sealer is.

Of course any "sealer" you use in a system is gonna "seal" stuff you don't want sealed as well.

It's also like "slime", "Fix-a-Flat", or other tire sealants. Yeah, they'll get you home, but the guy at the tire shop is not gonna be very happy with you when you take that tire in to have it properly patched. Cleaning that gunk out of the tire (or engine) is a chore.

Hopefully, "Plan B" - pull the head off and replace the head gasket - is still available.

It may be "Plan C" time.....

 

A 50/50 solution of water/white vinegar “may” dissolve the sealer. If you can scoop out some blobs, say from reservoir, you can test first: drop them in the solution.

 

Block sealers have often given two or three months of head gasket relief especially with early use on self sealing gen3 rattle victims. One overheat or hydrolock and the aluminum engine with thermal cycling problems in the cylinders is soon to be retired.

Even when used early, the most effective old school sealers need pure distilled water in the system which is extremely time consuming because of multiple drain, fill, warm, drain, fill cycles required. Most don't do this. If the engine is going to be history anyway, 500 miles with the sealer is best. Getting a proper dilution of antifreeze later is the next challenge generally requiring multiple drain fills again and use of a calculated amount of concentrate.

End result generally is a replacement engine. Might as well bite the bullet upfront. Head gasket if it has not overheated.

 

For dealing with a system that's largely water filled:

AFAIK 2nd gen Prius (and gen 3 and 4) can use Toyota Long Life coolant (without "Super"), which is a full strength concentrate. The only hitch is a shorter working life, say 1/2. So if you've done multiple water flushes, and last one or two with only distilled water, AND you know the system's capacity (spec'd in Owner's Manual I think), then:

1. Drain as best you can.
2. Add Long Life Coolant (full-strength concentrate), an amount equal to half the system capacity, or slightly more.
3. Continue filling with distilled water, bleeding air and so on. This should get you in the ballpark of 50% coolant mix.
4. Drain and refill with Super Long Life Coolant, at half the recommended service interval, say around 2 years or 25K miles down the road.

FWIW, in Canada the Super Long Life Coolant is sold in pre-mixed 4 liter bottles, at 55% strength, so I'd speculate anywhere between 50~60% is close enough, and preferable to a percentage lower than 50%. Too, if you err grossly on the side of too high a coolant percent, you can always rectify by a slight drain and refill with distilled water.

 

The coolant loop is the most cantankerous coolant loop ever.

3 way valve
Coolant heat recovery thermos
Aluminum head which makes it even scarier to over heat easily warped

really the last loop ever to inject sealant goop. Bad news is your engine is toast. It has seen severe overheats which most likely means the head is warped. That’s why the head gasket fails.