OVERHAULING A PRIUS ICE

everyone. Want to appreciate your efforts in proffering solutions to some of the problems I have had with priuses I have worked on.

I have got a Prius 2008, that's got 100, 863miles on it. It shortens oil more than necessary, getting to the level I have to top up the oil with more than 3quarts of oil.

The valve gasket seal has being replaced, and there isn't oil seeping out from the valve covers any longer.

Crankshaft oil seal, and the seal between the interface of the eCVT and the ICE, isn't leaking.

My conclusion now is to overhaul the engine.

Question is, I need some advice on precautions to take before embarking on the job.

Thanks everyone.

 

I really want to thank you guys for your various inputs. I just concluded the overhaul or rebuild of that engine (1NZ-FE) yesterday, and this was what I learnt:

05PreeUs: Have checked all that prior to opening up that engine.
When we did open up the engine, to our surprise, this was what we saw after inspecting the engine:

1.Piston rings, and oil control rings were worn(I meant the ring gap ends were beyond specification).
I'm still surprised how that could be, since the car is a 100+ thousand mileages.

2.All the rings(compression and oil control), were all not at the right positions (the 12-3-6-9 rings positions on the piston lands were positioned directly at the gorgion pin locations of the pistons. And that allowed more oil consumptions and excess fuel consumption.

3. Piston crowns and both exhaust and intake valves tops on the cylinder head, showed signs of engine oil seeps into the combustion chamber.

4. Spark plugs, intake and exhaust valves also had ash yellowish kind of deposits on their surfaces.
This made me to conclude that the yellowish deposits might be as a result of carbon and engine oil accumulation that has undergone exposures to tremendous amount of heat.
On some of the piston crown also, we noticed kind of blackish carbon deposits on em.

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I really never knew that OEM parts could be fitted wrongly from the factory. Or is it possible for compression and oil control rings to shift from their original positions after installation from the factory? I heard it doesn't shift, because the pistons only engage in reciprocating motion.
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69shovlhed: Well, you could get that engine there, but you the problem is, no one is sure of the mileages of those engines. And coupled with the fact that Prius parts in Lagos are very expensive, compared to a highlander or Camry hybrid.
To be on the safer side, I preferred to overhaul that engine e, with new OEM parts.
We replaced all the metal and beqrings,; O-seals, rings, water pump, chain, etc.
In a used engine, those parts may be on their way out already.
Though this project took us a week to finish, because we had to be very careful of the connectors of components.

ChapmanF: Refer to my response to 96shovlhed.

bisco: I meant, before someone undertakes such a project as an overhaul of such, what care, or precaution should one adhere to?
For instance, ensure blablabla is done, etc kind of.

Thanks everyone once again for your contributions

 

Those are the pictures of the car, and the parts replaced?

 

I didn't set the valves. There wasn't any noise or of some sort coming from the valves area at the top. I don't think there's any need setting the valves. They're controlled by the VVT-i mechanism.
Correct me if I'm wrong.

 

The car was bought from my second country, the "USA", used.
The oil shortages has being like that ever since.

As regards, MPG, I did a test drive this evening, and returned awhile ago, didn't bother to check that on the energy monitor. Would do that tomorrow.

My observations after the test drive:
1. Check engine/VSC/BRAKE/ABS lights suddenly came up, and brakes suddenly became ineffective.
Solution: scanned the car, and got a code related to hydraulic system fault.
Checked all the lines, discovered rear left had brake fluids leaking from the brake shoes.
Brake shoes were worn, and had to replace them, and some of the seals there.
Those lights were cleared with the scan tool, before driving the car.

2. While I was driving with the AC system on, and stuck in heavy traffic, there was intermittent red triangle caution sign with a temperature sign displayed on the MFD. Within some seconds, it disappeared. That tells me there's a temperature rise somewhere in the system.
Solution: Would get the car scanned tomorrow for codes.

3. Car feels smoother more than ever before now.


Thanks

 

A note of caution pls. Anyone engaging in an overhaul like this, must ensure.all connectors are properly connected back from where they were removed. That would prevent the battery from running out of juice, when it has to power the ICE.

 

...let me reintegrate. The connectors at the throttle assembly are two, in the gen2.
The one with lots of wires going into the throttle assembly outside of it, is easily seen. But there's one behind the throttle assembly, hidden that you can't see. So you'd have to search for it with your hands, or use an electrical wiring diagram.

 

Legends:
First picture: Prius being testdriben in traffic
.
.
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Other pictures are the leaky brake shoes/seals and the replaced parts.

 

Wao! Didn't know that Chap! Thanks for the info. But mine weren't making any noise, so left them. If it did next time, would take off the buckets and see what's in there.

 

Would post the MPG stuff later today as I embarked on the next round of test drives today

 

Returned from my final test drive today, and while the AC system was ON, and driving some miles, the triangle caution sign came on, at the same time, a thermometer sign in red. Check light also was on.
Scanned the car using tech stream, got a P1116 code.
Relaizsed the inverter coolant was some what low, and had to bled it of air bubbles.

Prior to when the engine wa overhauled, there wasn't such a code, and triangle caution sign.

I checked the connectors to the heater temperature sensor by the inverter, they were all properly connected.
Have cleared the codes after bleeding air bubbles from the radiator and inverter coolant systems.

Meanwhile, here are some pictures of the MPG.
Pls correct me guys, if in wrong in my calculation, and how do I do it the right way?