Overheating after full tuneup and Blue Devil

Head gasket is blown, money is wasted and perhaps low coolant now. That is is the optimistic assessment. Hopefully the repair attempts have not cost you the engine via overheating. Head gaskets are a known problem on 2010-14 Prius engines. By the way, when gambling the house always wins.

 

Plugs and wires? There are no wires. This car uses individual coil packs.

Sounds like a blown head gasket.

 

Time to DIY a new engine.

Perhaps a head gasket is doable

@Mendel Leisk can fill you in on the vinegar cleanse.

 

Don't ask me about using anything Blue Devil makes. Had a small leak in my PS rack with my Volvo and added Blue Devil as recommended. Leak stopped for a couple weeks, then started back up so I added a little more as the instructions stated. Two weeks later every seal connected to my Power Steering system was puking fluid. Needless to say the whole system had to be replaced due to damage the product caused to the seals.

 

Nothing complicated. There's one such product (I forget which, @cnc97 might be the guy who knows), an email to the company got a response, with the advice that acetic acid (vinegar) could dissolve their product, make it flushable. Specifically, drain the coolant system and fill with a 50/50 mix of water* and vinegar.

A method, just off the top of my head:

1. If possible, scoop a bit of the gloop, and test it with a small amount of the 50/50 mix, see if it's effective, disolves it. If not, that's all she wrote.

2. Assuming it was effective: mix up about 1.5 US gallon of the mix (a bit more than required), drain the engine coolant system, with cabin temp set to high. Then refill with the 50/50 water/vinegar mix, per the usual coolant change procedure (see attached).

3. Do another drain and refill, this time just with distilled water.

4. Do another drain and refill, this time start the refill with 3.7 liters or 3.9 US Quarts (slightly more than half of the system total capacity, per attachement), of Toyota Long Life Coolant**. Then complete the fill with distilled water. This should hopefully leave you with a 50/50 coolant mix, even with the residual distilled water that was in the system.

5. Since the Long Life Coolant does not have as long a service life, schedule a subsequent drain and fill with Super Long Life Coolant, say for 30K miles or 3 years max.

* Preferably distilled water I think.

** Long Life Coolant is the full-strength coolant Toyota offers. Super Long Life Coolant is the spec'd coolant, has a longer service life, but only comes pre-mixed.

 

Yes, that’s what Blue Devil recommended to neutralize their concoction of “maybe mechanic in a bottle”.

I would say that after the rinse, use a 60/40 coolant/water to compensate for residual water though. Peak and Prestone coolants say to go 70/30 for maximum protection, but I don’t see a need for protection to -84° F.

 

I would stick with Toyota SLLC or similar formula with phospate.

 

i have similar situation. 2013 Prius V. 236,000 miles.
About 130,000 miles had symptoms of head gasket failure. Used Bars which lasted for a while. Have added as needed and switched to K-Seal which was great for a while. Fast foward, have been blowing coolant out of the reservoir. Changed reservoir with cap and water pump - should have tried the thermostat at the same time. No change with coolant pumping out of the cap. The temperature sensor dash light comes on briefly if driving distance at higher speed. Goes off as soon as i coast and typically does not come back on. I am looking for the most direct answer to the problem and i'm hoping it's not the worst case scenario - that the engine is just too full of sealant and gunk to salvage. Is there any possibility cleaning the EGR valve, replacing the thermostat or flushing the radiator would alleviate the coolant blowing out?