Is New or Rebuilt Engine in Gen 3 Worth It?

Keep adding oil until the consumption gets bad enough to foul the catalytic converter or oxygen sensors. That should occur when the burn rate reaches a quart per 1000 miles. You're not there yet. Worry about it then. Motor oil is still cheap - an engine isn't (obviously).

And don't be concerned about blowing up the engine. If you're diligent enough to top off the oil level as needed you won't blow it up.

 

While you may find the oil consumption excessive -- most manufacturers say 1k per Qt .. some go as low as 750.

What oil have you been using? -- Toyota switched to 10k intervals with synthetic 0W-20. I would not be rebuilding an engine for 3qt in 5k of driving. I don't see why it would blow ? I'm not sure if they make high mile 0W-20 ... if they do .. try it.

 

As noted excellently above, club up to a 5w30 and monitor.
More later.....

 

What work have your mechanics done to the car? PCV valve? Intake manifold cleaning? Egr system? Tried an engine treatment?

What type of driving do you do? Can you go 5 mph slower than you currently are?

Plenty of things to investigate and explore before an expensive decision has to be made.

Keep adding oil and keep your Prius on the road.

 

If you don't mind sharing, how often were you changing the oil, following the US schedule? I'm not saying it matters, just curious.

 

Adding 3 quarts for $12 every 5000 miles, or $240 every 100000 miles.

Makes sense to me vs $3000 engine

 

Would you consider a used engine from a low-mileage wrecked Gen 3 Prius? If I could be sure of the provenance of the ICE in such a case and the cost was less than $1000, I would consider it. Just my $.02.

 

Not a defective engine, a worn engine. It's very strange that your oil consumption issue occurred over a very short time. Typically it occurs gradually and increases over that time. By the way, your Prius' oil consumption isn't nearly severe enough such that smoke would spew from the exhaust - a quart every 100 miles definitely, but no way with 1666 miles per quart.

I wonder what those gaskets were that the dealership charged you for - the Johnson rod maybe? Save your receipts in the glove box - you'll never lose them.

 

If the oil is burning it's probably from worn piston rings. You ought to be able to just replace the rings and the head gasket, but it is an involved process and you will almost certainly need to remove the engine.

This is why a used engine can make sense; you're removing the old engine anyway. It depends whether you can find an inexpensive, low mileage engine from a wrecked car.

 

Per @Raytheeagle : check again if PCV valve has been changed. Same with the EGR : what was done. The dealership should be able to find this info. The more aware you are of your car's history the better.

 

Also the more aware you are of the cars history, the better troubleshooting you or someone else can do.

 

More likely clogged and stuck with carbon, not worn (assuming decent air filtration).

 

So you can clean the rings without replacing them?

 

Engine treatments and performance restorers are options.

Some work, some don't. When I used the BG Products EPR before changing the oil, the oil came out jet black after treatment. So in my case this worked. I did it to see if I could reverse some oil consumption and get back to not adding oil between changes every 10 k miles. At 4300 miles on this oil, it is on pace to do that.

 

Can you enlarge on that, consumption before and since? Interesting.

 

Was consuming a quart of oil every 4500 miles since 120 k. Did the egr system and intake manifold cleaning, upped the oil from 0w-20 to 5w-30, EPR treatment and now consumption is now around the oil change interval of 10 k miles. Probably a little short, but still close.

I will be doing some experimentation with some oil additives to potentially improve lubrication. I use synthetic (Toyota or Mobil One), but if carbon deposits have built up once and led to blow by, what's to say it won't happen again? And with the engine logging more miles ( currently at 143 k miles), the situation will only get worse.

First test will be starting after thanksgiving: Oil change with Mobil One 5w-30 and BG Products MOA. Doing this oil change early as we will be going to So Cal to Disneyland after thanksgiving and want to see what mpg and oil consumption will be with this configuration going about 80 mph down I-5 and over the grapevine. I know what I have gotten on previous trips in terms of gas mileage and oil consumption, so this will be another data point.

But these are my observations and may vary.

 

On this subject: Have you guys found a good way to make reading the oil dipstick reliable? Because I almost always have a streak of oil on my dipstick that makes accurate reads impossible.

 

Yeah, someone here had a brilliant idea, works: remove dipstick and wait at least 5 minutes, before reinserting to do the check. Oil apparently gets pulled up the dipstick tube when you remove the dipstick, and it drains back in a few minutes.