Bought Used Gen3 2010 Prius IV @ 155k miles. What should be done?

Do you have any repair history on this car? You can run a carfax to see if there are repairs/maintenance that has already been done, so you don't have to repeat them. 155k miles, many things should have been done already

 

Yes, for engine water pump replacement. Also, be prepared for the head gasket going bad in the next 10k to 45k miles.

 

congrats and welcome!
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The top two links in my signature are EGR related (on a phone turn it landscape to see signatures). Also recently added an EGR cleaning workflow, here.

At your miles, I wouldn’t look at EGR cleaning as a “get out of jail for free” card; it’s late in the day to start with this. Unfortunately, it’s just about the time head gaskets start letting go, so tread cautiously, don’t make any major investments in it for the next few months; just deal with the EGR, then wait and see for a bit.

 

B12 or other piston soaks won’t help a gen3 Prius burning oil because of their low tension piston ring design flaw. Save your money for a rainy day fund.

Try to avoid dealer repairs. Sometimes their diagnostics are ok but their repair costs are often 150-200% higher. Do find and use an independent hybrid shop before you need it. 5k mile oil and 50k mile coolant changes are your best bet.

 

At 155k miles, I would go for the full works. Try to get parts from the dealership or rockauto. Ebay has a lot of fake parts

1. plugs
2. pcv valve
3. change coolant
4. change transaxle oil
5. change brake fluid and check brakes
6. change water pump (you can get away with changing the rotor only or if you want to splurge change the pump using OEM pump)
7. clean throttle body
8. clean entire EGR circuit

I wouldn't overly invest too much money on this car. Since it's burning a lot of oil and it's nearing it's head gasket replacement time (anytime over 150k miles). I would just do simple basic needed maintenance.

 

2. PCV valve is easy and it could be part of the reason why you're burning so much oil. You would normally do this along with the EGR circuit clean, the removing of the intake manifold would expose the location of the PCV valve.
4. Transaxle fluid - this is not urgent since Toyota considers this to be a lifetime fluid. But we all know there is no such thing as a lifetime fluid.

I would tackle the water pump, throttle body cleaning, and EGR circuit at the same time. The water pump is actually very important to change out as it could fail and you could end up with an overheat condition that ultimately leads to (contributes to) a head gasket failure. Since you've already changed your coolant, you would just drain and fill that coolant back into your system during the water pump change.

The bad news hasn't really been shared with you yet. These cars tend to have 3 big failures. 1. Brake booster pump, 2 Head Gasket, 3 HV battery. Any of those 3 items will cause you some big problems and are big ticket items. So hopefully you can put away some money in anticipation for when those repairs are needed.

 

Don't let some people scare you. Because they had issues they want others to share in
there misery... And it makes them feel better if they can scare others. EVERY car has issues.

I'm at 360,xxx miles on my 2010 and no issues with the brakes. I know sooner or later I will
need to replace those parts. It's 15 years old! With a LOT of miles. I replaced the head gasket
at 301,000 miles. And the hybrid battery 6 months or so back. Even with all that it's a LOT less
than a new car, or even a used car.

If you can do the work yourself, no labor cost. That usually about 75% of the cost of repairs.

If you listen to the brake pump, and how often it runs, that will usually give you a heads up on
if it's starting to go. When I bought my Prius in 2017, it ran every 35 second or so. Some on here
said it was going to fail anyday. 7 years later, it's cycling every 25 or so seconds....
Yes, some have just failed, seemingly without warning.

I drive 85% highway miles, as the previous owner did. Those who drive mostly in the city, seem
to have more issues sooner, like the head gasket.

So ENJOY your Prius. If/when an issue arises, repair it. There are more people NOT having
issues then there are that are. Some people think that they should never have any problems.

 

Since you already bought the car, the easy option to avoid it has past.

B12 can't help a car with low tension rings as the block gets damaged quickly. Usually you hear "it went from a quart every 800 miles to a quart every 1300 miles." Many controlled tests have shown no improvement. Early on Toyota replaced pistons and rings for free. Low tension ring oil burning was widespread on many Toyota models through 2014. It also clogs catalytic converters, another big expense.

Brake boosters are difficult and no aftermarket options exist. It requires a tricky flush and calibration with Techstream. Many diy replacements fail at this step.

Head gasket fails on an oil burner means another engine. This has become expected on gen3s and the problem had revised parts and software thrown at it by Toyota. No help until the gen4 engine redesign that was successful and is essentially still used today.

Inverters suddenly fail and strand you. A class action suit on this may cover you but that's small consolidation if you can't trust the car any distance from home.

Water pumps are the least of the problems. Timing chain oil leaks are common.

Almost anyone with experience with these would have warned you to avoid if you asked up front. As is you can install JDM or rebuilt engines, have a quality independent do the brake booster and stay close to home so the inverter does not strand you badly.

It is possible to spend $10k to keep a used gen3 100%.

 

Another one bites the dust...... fear!

 

No, But it "might" slow it down.
You didn't say what type of driving you mostly do, city or highway.

 

Not enough data available. Not enough to bank on, anyway.