2010 Prius not driven - how to get running again?

Have you charged the 12v battery yet? Eveyone is waiting!

 

Probably you just need coil or spark plugs. Swap the coil and see if it changes from p0304 to p0303 if you swap cylinder 3 and 4. If it does not change, change the sparkplugs.
Change the oil and wait if everything gets better. The iron in the cylinder wall and cylinder rings may get corroded by not running it for a long time. The oil consumption maybe better over time too.

It is recommended to run hybrid car once a month for about 1 hour to recharge the 12v battery and let the engine warm enough. Or make a long enough trip for 30 minutes.

I don't worry about head gasket on 2013 or newer Prius. Don't be panic or make conclusion without proper diagnostic. Check if the coolant level are ok, not dropping every week.

If it is 2010-2012 and burn a lot of oil plus head gasket problem. It is better to swap it with 2015 engine. The 2015 has revised piston and piston rings, no oil consumption.

How often do you need to add coolant and how long it had been like that? Coolant kill catalytic converter. I never need to add coolant on my 2015 even after 70k miles, it is still at the same level as new.

 

Brake fluid is the last thing we need to worry in Prius. It is still in very good condition even adter 10y/100k miles in both anti corrosion and water content ~1%. Clean and lube the sliding pins with silicon grease is more important on Prius brakes.

Transmission fluid still need replacement and every 90k is enough.

The most important thing is engine oil change every 5000-7000 miles/6 months from the facts of how it starts burning oil from carbon build up on the oil control rings. 10k miles interval is a little bit too long in most Prius owner.

Cabin filter and HV filter cleaning/replacement should be done annually.

Coolant is not a problem. 150k miles/7 years is more than enough and indeed we never need to top off.

Toyota should recomend Intake manifold and EGR pipe cleaning in 3rd. Gen as part of 120k maintenance together with spark plugs.

 

last seen 11/12

 

Has the FBI been notified?

 

It is probably sold. Burning oil + head gasket is not the end of the world. The problem next is catalytic converter that could be costlier than used engines. 2015 Prius and up is the best bet. It does not burn oil, less problematic EGR and makes the head gasket problem much less likely.
I understand the feeling of car that is totaled from head gasket, catalytic converter, and aging HV Battery. Hopefully no additional problems like brake booster and AC evaporator leak like many gen 2 had.

 

Wow, some really pessimistic replies here.
I wouldn't change the oil or the plugs or even the fuel. Or the tires (if you they can hold air). I wouldn't even buy a new 12volt battery. I would try to see if the old one charges first. It may, you may need to charge it at a slow rate. But seems you already got a new one.

Just check the fluid levels. Add if necessary. You may add some fuel stabilizer if you are concerned. Then crank it up. I can't comment on the misfire. It could be many things. But the car should start if you have enough charge left on the Hybrid battery pack. If the HV pack is low in voltage, and can't turn the engine over or turns very slowly, then you will need to charge those battery modules.
So just try it, your car will not blow up

 

if the 12v is good, you should be able to put it in neutral and push it.
if not, they can put dollies under the wheels and move it.

but i have to ask, why new tires? seem like you'd want to get it running before making that investment.

once you get a complete diagnosis, you may not want new tires anymore.
cracked sidewals aren't a danger except at highway speeds and hard cornering.

 

There are many advice here for the OP. But it seems like the OP does what they want to do. Getting that car towed to a shop to get the tires replaced before checking out the condition of the car first is plain crazy to me. But it is their money. We cannot tell them how to spend it. We can only advice and we did that.

 

I would not spend any money besides basic safety (tires and 12V battery) first on 2010 Prius. Honestly, 2010-2011 are the worst period of 3rd gen.